In early March 2023, I picked up my second RIA 52000 Pro Ultra Match 6″ HC 10mm pistol – more affectionately known as “The Big Rock”, which is exactly what it is. I sold my first Big Rock many years ago because I needed the funds and regretted it once I started making custom 10mm mags for whole family of high-cap 10mm and .40 S&W RIA pistols. I couldn’t buy a new one at the time because Armscor, who owns RIA, only seems to make them periodically. Maybe 2-3 years later after I wished I had it and was looking, 52000s started popping up on my saved searches – Gunbroker alerted me first and I bought one about a week later. [A number of places have them now including GrabAGun – click here]
I should add that as soon as I ordered the pistol, the next thing I did was to order another set of grip panels from Mark Browne. His grips just look and feel great compared to the rather boring but durable G10 composite grip panels that come with the pistols.
Bottom left is the new Big Rock with its factory grip Panels. Above it and to the right is the 51679 with Mark’s wood panels. The lighting doesn’t do the wood justice.Here is a better view of the wood on the 51679 plus you can always go to the blog post about it and see more.
The new panels for the Big Rock arrived
I emailed Mark and told him how much I liked the first set and he said he’d look for one with plenty of grain and contrast. What showed up was awesome.
…Wow…
Fitting them to the Big Rock
While RIA does use modern CNC machines to make the frames, the funnel fitment can vary – I know this based on clients that have fitment issues with the relatively shorter 9mm mags using Dawson Base Plates. Either they do not use a jig or it moves and wheter the funnel sits exactly can very. Why this matters is that you may find the panels go right on or you may need to fit them. DO NOT FORCE THEM! So let’s step through this.
Each OEM grip panel is held in place with two unique Allen head screws. Remove the screws and the panel lifts right off. Note in this photo how very little material is between the grip screws hole and the funnel – that’s tight. The pistols are made in the Philippines and then need to travel across the Pacific. They liberally coat these pistols in preservative oil and this is one example of how much they use. Have a towel or rag handy to wipe this stuff off before you start installing the wood panels. By the way, this is typical of all the RIA 1911 pistols and again highlights why you need to clean them.This side went right on without adjustments being needed. That was an unexpected pleasant surprise. They panels need to seat fully without pressure being needed. If you try to force them in, something will snap.Everything is nice and flat and the screws went in without forcing them. The screws are installed until they are firm – not so tight the wood snaps – they just have to keep the grip panel in position, You do need to use a dab of medium-strength screw threadlocker such as Loc-Tite Blue to keep the screws from backing out.The other side had issues. Teh funnel was riding high here and the panel would not even seat fully. To adjust the wood, take a single cut file and remove a bit of wood from the bottom and try over and over.Fitting is slow work with wood. It is better to be able to take more off than wish you could put it back on. After maybe 5-10 minutes I thought I had the panel good to go but it was still riding too high and the screw could not seat properly. So, more fiiling and testing until it fit completely. Take your time and you will get a nice fit without a gap. This is a great example of time, patience and handwork can generate a far better end result than being in a rush with a sander and taking off too much. The bottom is the new Big Rock.The top is the new Big Rock with it’s 6″ barrel and slide. I really like the gloss finish. It really brings out the contrast in the wood.
Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.
If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.
I genuinely like the Rock Island Armory (RIA) double stack 10mm pistols. I jumped into the deep end of the pool and started converting some really cool Mec-Gar Para P16 mags for use in the 10mm and .40 S&W pistols for folks who need either 10 or 15 round limited pistols due to unfortunate magazine limit laws where they live. The feed lips must be shortened and reprofiled to work reliably in RIA double stack pistols.
I’ve written about the conversion and you can click here to learn more but I didn’t really show a lot of photos of the different Dawson Precision base plate options. In addition to changing the feed lips, you have to replace the plate because it literally will not fit in the funnel – it’s a show stopper plus it really does need to be longer to allow for positive seating of the mag in the pistol. You could grind the OEM plate down but then you would need to glue/add material so you can fully set it – note, if you do that, leave a hole so you can unlock the plate in the future.
This post also applies to folks who own the RIA A2 HC double stack 9mm pistols. The same base plates are used on the magazines for your pistols as well and the magazine capacity is limited to 15 rounds as a result.
At any rate, here are a number of photos showing the Dawson Precision base plates and get a better idea of their different thicknesses relative to each other as well as when fully seated in the pistol:
The Dawson plates are machined from aluminum and their sizes are how much thicker they are than the original Para P16 base plate shown on the right. The bottom left Dawson plate is their +200 model and the one above it is the +300.
Here are the three Dawson plates next to each other on our converted P16 magazines. The +100 is on the left, +200 in the middle and +300 on the right. They increase the height and weight of the mag but do not increase the capacity.
With our 3rd Gen mags, Mec-Gar started using the left polymer plate and it works great in the RIA pistols. Both it and the +100 Dawson plate sit flush in the RIA mag funnel.
These 15 round windowed mags all have +100 Dawson plates.
This is a +100 Dawson plate in my RIA 52009 Ultra HC 10mm pistol.
This is the +200 base plate.
This is a +300.
This is the 3rd gen polymer Mec-Gar plate that comes on the 10mm/.40 S&W mags for reference. It fits the RIA funnel just fine.
I do need to note something – out of the two to three hundred converted P16 mags I sold, two buyers had pistols where the distance from the mag catch to the bottom of the funnel would not allow the mags with the Dawson plates to fully seat. I gave them full refunds and don’t know if the issue was the mag catch or the fitment of the funnel to the pistol. Again, only two gentlemen out of hundreds. I really do not think it was an issue with the base plates just to be clear – just stacked tolerances going in the wrong direction.
Summary
Dawson Precision makes great base plates for Para P16 and P18 magazines that enable them to fit in the funnel of most RIA high cap 9mm, 10mm and .40 S&W pistols. They come in three sizes and you can choose based on your preference.
Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.
If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.
If you’re reading this, I’m going to assume you are either the owner of a Rock Island Armory (RIA) high capacity 10mm or .40 S&W 1911 pistol – sometimes called a 2011 – or you are thinking about buying one. The RIA pistols are workhorses and I honestly have no reservation recommending them. What I really want to cover in this is post is to tell you about our magazines for these pistols and why I think they are the best.
Yes, I Really Own And Shoot Them
I currently own two of the high cap 2011s, a 52009 Rock Ultra FS HC in 10mm and a 51679 Tac Ultra FS HC also in 10mm. My point is that I actually own and shoot the pistols – I’m not just some guy designing to specification who doesn’t actually shoot — I actually do shoot them and I’ve developed some insights as to what makes a good reliable magazine for the RIA FS A2 series of pistols.
What Got Me Started?
What got me into the mags originally was that I bought my current 52009 during the pandemic panic and there weren’t magazines to be found anywhere. Tons of websites said they were out of stock and then ones that did claim to have them turned out to be scams or backordered them. This drove me to do some research, that I’ve documented in the past, and resulted in a series of generations of magazines starting with base Para P16 magazines and evolving to our current third generation.
Here’s a sibling photo: The 51679 Tac Ultra FS HC is on the top and the 52009 Rock Ultra FS HC is on the bottom. The only two differences I have noticed is that the 51679 has a threaded barrel, serrated slide and a Picatinny rail on the bottom of the frame. Otherwise, they seem to be the same pistol.
Two Questions I Get Over And Over In Email
There are two things I constantly have to answer in emails – are we a real business or another scam? Yes, we are a real business and got our start making AK grips and handguards back around 2006-ish. We’ve since slowly grown our small family owned business since. Yes, if the website says we have them in stock then we have them in stock.
Second, people ask why they should buy our magazines and not the ACT-Mags sold by RIA (they are the OEM supplier to RIA by the way) and other resellers? For months we were the only supplier actually shipping magazines and people bought about 500-600 mags without ever asking “why you folks?” Well, now that there are options again between us and the ACT-Mag and tons of sellers selling them, that’s an honest question that I need to try and answer because I really do think we offer the best magazine for these specific pistols.
Here’s one of my personal magazines loaded with Underwood 200gr bonded hollow points. They function great in the pistol. I actually have not found a round yet that the 52009 pistol in the background can’t feed or eject properly.
Why Our Magazine’s Are The Best
First, we start with an Italian Mec-Gar P14-45 magazine. Mec-Gar makes tons of magazines and they know their stuff. In fact, they are a family owned business founded by Mr. Edoardo Racheli in 1965 in Italy for the sole purpose of making firearms magazines.
Rather than reinvent the wheel and learning from scratch, the base magazine I start with is Mec-Gar’s P14-45. That magazine reflects a ton of lessons learned that Mec-Gar has incorporated over the years and let me give you the big ones:
Second, unlike some mags that just have a blued finish on the steel, our Mec-Gar mags have a very cool advanced anti-friction coating that makes loading easier and far smoother feeding. The coating also reduces the risk of corrosion and does not require a lubricant – some magazines use a liquid lubricant that can attract dirt and lead to feeding problems.
The left magazine is made by ACT-Mag and it is what comes with RIA pistols. The right magazine is one of our’s – note the anti-friction coating on it vs. regular bluing on the OEM mag.
Third, we use a variable geometry spring that enables easier loading and reliable feeding regardless of the number of rounds in the magazine plus they can be stored loaded. The whole design of the follower, spring, floor and baseplates is very well thought out.
The ACT-Mag spring is on the left and does not use a floor plate. The Mec-Gar’s variable geometry spring and floor plate retainer are on the right. The tab on the right side of the floor plate rests in a notch in the magazine body to orient the plate and spring accordingly.
Fourth, our magazine’s spring, floor plate and base plate are all captured / locked in place and aid with easy disassembly and re-assembly for cleaning. The ACT-Mag use a tool-less design and while that makes closing the base plate a bit of a challenge because the bottom of the spring wants to escape plus the base plate can be shoved off the magazine accidentally as well.
The ACT-Mag tube, tool-less base plate and magazine spring assembly are to the left. To the right of the middle are the Mec-Gar variable geometry spring, locking base plate and tube — all based on years and years of experience and innovation at Mec-Gar. The tool in the photo is something I made to speed up the disassembly of the magazines in bulk.
An OEM ACT-Mag is to the left and one of our Mec-Gars is to the right. The notch in the front of the magazine body’s base is where a tab from the base plate on the spring sits. Everything is nicely locked in place by this elegant design.
Here’s a view of one of the magazines fully seated in the pistol. You have the big flared mag well around it and the button in the middle locks the base plate to the floor plate. It needs to be depressed for the base plate to come off.
Fifth and most important – every single magazine we sell has the feed lips adjusted specifically for the RIA pistols. I use tooling that I developed to change the feed lips for optimal feeding and retetion.
For testing, I use dummy 10mm rounds and insert them by hand to feel if anything is wrong during loading. I also cycle them by hand through either my 52009 or 51679 to ensure proper feeding, retention and slide lock on empty. I’ve found tons of things that can go wrong and have refined my tooling, processes and testing to produce a magazine you can count on. This RIA-specific tuning is where we add the value and I will stand behind them if you run into a problem and need help.
Every magazine is tuned and tested to confirm it will load a 10mm round directly in the chamber. Testing is done with dummy rounds but for the sake of the photo, this is an Underwood 155 grain HP round.
Underwood 220 grain hard cast – One of my bear defense loads. I carry Buffalo Bore also. Note how the front of the feed lips are securely holding the round in place. The lips are not just about feeding but retention also or the rounds would be popping out from under them at the wrong time.
One last photo 🙂
Summary
We pride ourselves on our customer service and small town family owned business values. We only sell stuff that we actually use as well. I really do think our magazines are solid and reliable and are worth it. I wouldn’t be using or selling them if I thought otherwise.
Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.
If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.
This is our third generation of magazine for the Rock Island High Capacity FS A2 10mm and .40 S&W pistols that use the 16 round magazines – not the single stack 7-8 round mags.
This is one of the new mags. You can see a dummy 10mm round poking out from during testing.
These are converted Mec-Gar Para P14-45 magazines that have the feedlips adjusted and fine tuned to properly retain and feed 10mm rounds. Note, a normal P14 mag can’t securely retain a 10mm round. These tuned mags will only work with 10mm and .40 S&W. They will not work on any other calibers or in a pistol that requires P14 mags.
To properly retain a 10mm round, the feed lips must be properly spaced plus this must be done correctly or the feed angle will be wrong.
The adjustment process and tooling took some work because Mec-Gar uses surprisingly resilient hardened steel magazine bodies and feed lips. I had to develop a means to convert the magazines using a forming jig I developed.
Here’s a closer look at the mag lips. The finish wear is from the adjustment process.
Compatibility
These custom mags should work with RIA pistols that use the OEMP164015B magazine including the following pistols:
51994 TAC Ultra MS 10mm
51914 TAC Ultra FS 10mm
56862 TAC Ultra Threaded 10mm
52000 PRO Match Ultra 6″ HC 10mm
52009 Rock Ultra FS HC 10mm
51738 Pro Match Ultra H – 40S&W – note, I tune for 10mm as I don’t have a .40 so some minor adjustments might be needed.
Observations
Based on my past experience and some research, there are some really cool benefits from the new Mec-Gar P14 design:
Hardened steel bodies and feed lips will hold up very well with extreme use
Mec-Gar developed an anti-friction coating that aids in feeding
The magazine spring is made from type “D” music wire and holds up nicely
They developed a polymer base plate that fits very nicely in the large RIA mag well funnels
The slightly taller magazine body clears the RIA mag-well funnel very easily. It’s longer than our previous generations of magazines and is even slightly longer than the original RIA/Act-Mag magazine
The magazine’s capacity is 16 rounds of 10mm. I was able to get 17 rounds in during testing but I feel that last round is just too tight. Thus, I am listing it as 16 rounds.
The polymer base plates work very nicely with the RIA pistols. You don’t need to change them unless you prefer longer plates. We do sell Dawson base plates if you wish to have one that extends further than the included Mec-Gar plate – The Dawson +100 plate is about the same height so if you do want the mags to be taller, you’d need either a +200 or +300 to see a difference. Please click here if you are interested in the Dawson plates.
These are all P14 mag bodies but with the different base plates installed so you can see the difference in thicknesses. The plates just change how tall the magazine is – they do not add capacity.
The OEM Mec-Gar base plate fits the RIA mag well funnel just fine. I set aside four mags for myself and am using the original base plate for them.
The Mec-Gar spring seems pretty robust. If you want an even stiffer spring, we do sell Wolff magazine springs that are 10% stronger than the originals. Please click here if you are interested.
The top mag is the Wolff +10% model. The middle is an OEM Mec-Gar without the floor plate and follower and the bottom is one with the floor plate and follower. Note, the Wolff Spring does require bending at the top to properly hold the follower.
After the mag lips are tuned, each magazine is tested in both my 10mm RIA 52009 Rock Ultra FS HC and 10mm 56862 Tac Ultra pistols to ensure proper fit and feeding. You may find some final tuning is needed on your particular pistol and it is easy to do – please click here for more information.
This is my 56862. You can see one of the new mags peaking out of the bottom of the big flared mag well.
Here, one of the new magazines is in my 52009 that is locked open.
One small detail, since these were originally for .45 rounds, the mag round indicator counts doesn’t match since you will be loading either 10mm or .40 – usually you have one or two more rounds of 10mm/.40 compared to what the round count hole label says.
These holes were calibrated to .45 ACP rounds so the slightly thinner 10mm / .40 rounds don’t quite match up. You can fit 16 rounds of 10mm in here – not just 14.
Ok, this is pretty interesting. The magazine that Rock Island ships with the high cap pistols is made by Act-Mag and is in the middle. Notice that the original Mec-Gar P16 is a bit shorter and the P14 is just a tad taller. For anyone who found our earlier mags to be a tight fit, I’d bet the new ones will fit a lot better.
Conclusion
I feel like we’ve come a long way since the first P16 conversions. This mag is solid and comes in at a far more affordable price point than the P16s that needed the Dawson base plates also.
If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.
I started digging and found out that the Mec-Gar MGP164010B is the exact same magazine except Mec-Gar used a hydraulic press to form dimples in the tube to stop the follower at 10 rounds for folks with Para 16 pistols in areas that had a 10-round limit.
I brought in a bunch of the 10 round mags and converted them for use in the RIA pistols. Then, the supply of the MGP164015B mags dried up and I decided to figure out how to convert the MGP164010B magazines for use in 16 round RIA .40 and 10mm pistols.
To make a long story short, you drill out the dimples, remove the burrs from the inside of the tube and then sand it down. That’s why the mags have 3/8″ windows drilled in them. The fact the magazine bodies were tempered steel definitely made life interesting when it came to the drilling and deburring operations.
Here’s a Mec-Gar 20 round magazine that is about to get the dimple drilled out. I made the jig to securely hold the magazines during the drilling operations.
Folks, I have gone through a ton of dummy rounds prototyping and now testing the magazines. I also use a MagLula to help me load every magazine and with 15 rounds. I am testing that the load and feed smoothly. If they do not then that would tell me something needs more work in the tube.
Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.
If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.
It was brought to my attention that there are owners of high capacity (HC) Rock Island Armory (RIA) Full Size A2 pistols who are in a jam because where they live limits their magazine capacity to 10 rounds (California, Connecticut, Washington DC, Hawaii, Maryland, Massachusetts and New York state to name a few. The problem is that nobody is making 10 round magazines for these “high cap” RIA pistols — until now.
The following are the 15-round 10mm and .40 high cap RIA pistol models that I am aware of:
51994 TAC Ultra MS 10mm
51914 TAC Ultra FS 10mm
56862 TAC Ultra Threaded 10mm
52000 PRO Match Ultra 6″ HC 10mm
52009 Rock Ultra FS HC 10mm
51738 Pro Match Ultra H – 40S&W
3/24/2024 Update: This is an obsolete post and product. We now make 10 and 15 round magazines by blocking and pinning closed our third generation magazines. These new mags have excellent springs and an anti-friction coating. Please click here for the product listings.
How did we make a 10-round magazines?
Okay, good question. The RIA pistols are related to Para Ordnance pistols (Paras) so magazines for those pistols can be adapted. Mec-Gar is a large players in the magazine market and it just so happens they make a number of magazines for the Paras including ones with 10-round limits – the MGP164010B – “B” meaning blued and MGP164010N – “N” meaning nickel plated.
This is the Mec-Gar MGP164010B magazine – the feed lips need to be trimmed and opened up and the baseplate needs to be replaced as the long front tab will not fit in the big mag well funnels that RIA puts on their pistols plus they really need to be longer to allow you to effectively smack that mag into position in a rush. Last comment – that dimple is pressed in with a die and limits the follower from going down to far such that only 10 rounds can be limited.
The above magazines are essentially Mec-Gar’s 15-round Para P16 MGP164015B magazine but with the dimples pressed into each size of the magazine limited the capacity to 10 rounds. So everything I learned about converting the Para 16 mags over for RIA HC use applied here not to mention the jigs I had worked out to do the work.
These are three examples of the converted 10-round magazines ready for RIA HC pistol use. The thicker Dawson Precision +200 base plates protrude just a bit from the big RIA funnel and allow for positive seating of the mags (that’s a fancy way to say “slap them in so they seat fully”).
This is a better view of the modified feed lips. The magazines retain their original followers that lock the slides open.
The +200 base plate extends just a bit below the funnel.
Because of pistol and magazine variations, you may find that you need to adjust the feed lips just a bit for your pistol. This sounds daunting but it is actually quite easy. Click here for the blog post on that.
I have an initial batch of magazines ready for sale and have more if the Para mags coming in. I don’t know how secure the supply will be of the Mec-Gar 10 round magazines but I will try to keep them in stock.
3/24/2024 Update: This is an obsolete post and product. We now make 10 and 15 round magazines by blocking and pinning closed our third generation magazines. These new mags have excellent springs and an anti-friction coating. Please click here for the product listings.
I hope this helps you out.
Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.
If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.
Hi folks, I am just trying to get the word out there that we actually have OEMP164015B compatible magazines that the 10mm and 40mm high cap 2011-style RIA pistols use in stock.
The base magazine I used to create these mags are the very well made Mec-Gar magazines for the Para P-16 (mag model MGP164015B). In addition to being close in terms of the required tube design, the Mec-Gar mags are quality and feature:
heat treated tubes
high tensile music wire springs
the follower is made from high impact nylon and locks the slide open
These mags were all converted by me and then hand fit and tuned to my RIA 52009 high cap 10mm pistol. For most shooters they should be good to go. If there is a feed problem then a minor adjustment of the feed lips (perhaps opening them a tad so the round sits higher) should be all that is required.
This is my personal 52009 10mm pistol. The magazine on the left is one of mine and has a +100 Dawson baseplate on it. The mag on the right is an original OEMP164015B that is made by ACT-Mag for RIA.
To accommodate the flared mag well that RIA put on these pistols, I used a variety of lengths of Dawson Precision base plates. The +100 Dawson model pretty much is flush with the bottom of the flared mag well, the +200 sits just a bit lower and the +300 is lower still. The number refers to the length (0.100, 0.200 and 0.300 inches).
Here’s a picture of three converted mags. As the text says in the photo, from left to right the Dawson Precision base plates are the +100, +200 and +300 models.
Our prices start at $69.99 and go down (not up) the more you buy. I just saw some of these magazines listed for the first on GunBroker this morning and they start at $80 and go up!
If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.
In the first post, I outlined the problem that high cap Rock Island Armory 10mm magazines (OEMP164015B) are next to impossible to find right and and shared some of the research I did. I also let the cat out of the bag that I figured out a way to successfully convert Mec-Gar Para P16 magazines (MGP164015B) for use in the RIA pistols.
Safety Comment – Use Dummy Cartridges / Snap Caps
I said this in the first post and it is so important that I want to reinforce the message – I knew I was going to need to do a ton of cycling of rounds. Using live ammo is risky because you have the very real risk of a negligent discharge. To avoid this, order yourself in a bunch of dummy cartridges. There are sellers on eBay that will sell you 10+ at time. Order yourself in 10-20 rounds. You are going to smash the crap out of them due to the heavy recoil spring a 10mm uses. I trashed at least 10-15 of them. Most were due to the bullet being smashed back into the case, one dented the case pretty bad and one deformed the case right at the mouth.
I can’t even guess how many cycles I did – especially starting out. I’m going to hazard a guess and say I averaged about three cycles per dummy before something failed on the dummy as I worked out the kinks and I would load three rounds per magazine to do the testing.
I can’t stress it enough – get dummies to tune your magazines.
Comparing the RIA and Para Mags
Per the first post, Armscor’s RIA mags are actually made my ACT-Mag. Since my pistol did not come with a mag, the seller was able to get Armscor to send me a OEM mag so I had a baseline to compare to. I definitely made sure it function tested properly before doing anything else. Never assume something works until you test it – I can’t stress that enough.
To let you see the differences, here are photos with comments in teh captions of the two mags:.
The RIA model has a plastic baseplate and the the Para model (right) has a steel base plate. Look at the top – the feed lips are much longer on the Para. The magazine locking slot is the same.
RIA on the left – see how the baseplate is stepped. This clears the big mag well funnel on the RIA pistols. The longer flat metal base plate runs right into the funnel and prevents the mag from seating. The RIA model has “40 SW Made in Italy” – the 10mm uses the same mag. Now the Para mag has more marking. On the left edge of the mag in the photo you can see “-A-” and on the right lower-edge in says “MG P16 .40-15”. The followers are a tad different and again the different length feed lips are apparent.
From left to right: Para, RIA, empty Para tube. The RIA follower is slightly different. I found that they work okay but I wasn’t sure at first.
Top is the RIA base plate and the bottom is the Para. The Para’s metal plate is too long but can easily have the front ground down to fit the mag well. The tapered top of the RIA base plate can clear the funnel. The Para’s plate is more like an immediate shelf or duck’s bill that hits the front of the funnel. The other three sides of the Para base plate are fine.
What Needed To Change?
There were two things that needed to change for sure and one maybe:
The feed lips on the Para were too long thus preventing the round from pivoting up to align with the chamber. Fortunately the Para lips need to be trimmed. It would be far harder, if not impossible, to lengthen the lips if they were too short.
The base plate needed to either be trimmed or replaced to fit in the mag well funnel
This was the “maybe”: The followers were slightly different and I didn’t know if the original Para follower would work or not. I figured that I would address the first two points and then decide the next steps. Let’s start with the easy one – what to do with the base plate.
Changing The Base Plate
You have two options here and either one works – it’s up to you. When you remove the Para base plate you will notice that the tube of the magazine’s body rests in a cup. You can remove that front tab off just shy of the depression. I left about a 1/4″ in front. This serves to stop the plate and located it properly on the plate. Seriously – just file, sand, or otherwise cut the extra material off. I used my big 2×72 Esteem grinder to remove the extra material and round the edges.
On the left is a modified base plate and on the right is an original. I reprofiled the plate on my grinder but you could use any tool you are comfortable with. Just remove material until the magazine seats fully. The above modified plate has about a 1/4″ or a tad more of material on it. You just need to leave enough for the plate to be positioned appropriately on the magazine. Yes, the mags do drop free.
The pro of the above is that it is fast, easy and cheap to do. The con is that the bottom of the magazine sits further into the mag well than I would like. You could easily add .100-.200 of material on the bottom using somethign like Kydex or G10 and some quality epoxy or a stiff rubber with an adhesive tape. In all cases be sure to drill or punh the hole out so you can remove the plate in the future – I had that mistake many year ago and learned a lesson – it is way easier to make the hole before you install it and need to remove the baseplate!
Your second option is to buy an aftermarket base plate. I bought some plates from Dawson Precision that I really like. Their +100 plates sit flush with the mag well, the +200 extends just below/outside of the mag well and the +300 sits further yet. All three work and it comes down to preference.
Here are two Dawson extended base plates on the left. The top left is their +300 model and below it is the +200. My modified plate is in the magazine. The Dawson plates are CNC machined and fit perfectly. I like both.
Changing The Feed Lips
This step is slightly more involved than the baseplate. In this step we need to shorten the longer Para feed lips. Again, I was really happy they just needed to be shortened. I was expecting to need to change the angle but shortening them isn’t as bad as you may think.
This is where having an original RIA mag to compare to the Para mag was invaluable. I needed to remove the same amount of material from the front of both feed lips. After watching the pistol load the mag and feed dummy rounds as closely as I could, I decided to use my grinder to remove material in a straight line from the front top edge to where I wanted the new front of the feed lips to be.
Rather than measure and transcribe, I used a steel divider (compass) that was my grandfather’s. I like doing stuff like that when the occasion suits. A divider wants to spring open and a small thumbscrew allows you to adjust the gap between the two points. In the case of the feed lips, I could use it to duplicate the length of the feed lips to each new magazine I needed to cut down using the back of the feed lips as the reference point.
Adjust the divider so the points are at both ends of the RIA magazine’s feed lips. This makes it extremely easy to scribe the mark for where the feed lips will be trimmed to on the Para mags. Yeah, these dividers are old. They belonged to my grandfather, then my dad and now me. Using tools reminds me of projects with my dad and the importance of family.
I would then use a scribe with a carbide tip to etch the distance and a small steel rule served as a straight edge from which I scribed a line at an angle from the front top edge of the magazine tube back to the length I just scribed.
Two things – first you can see the line I will grind down to marked on the magazine body. Second, the scribe has a carbide tip that cuts right through the finish and makes a real easy line to see. The first scribe I tried had a hardened steel tip and it didn’t make a very clear line. The carbide tipped one bit right in and easily scored the finish. Get a carbide tipped scribe if you can. I tried varying the angle it didn’t seem to make a big difference. I tried to more closely follow the original edge of the magazine with latter magazines.
Everything above that line needed to be removed. Again, I used my big 2×72 belt sander, or “grinder” as knife makers call them. I squared my work table to the belt, used a 80 grit belt and removed the offending steel by carefully pushing my scribed line towards the belt in a parallel manner. In English, I sanded off the metal above the scribed line 😉 Any kind of sander would make short work of this but it will be way easier if it has a flat table that will enable to you feed the magazine towards the sanding belt or sanding disc in a controlled manner. I would not do it free hand – same goes with a file but I’ve also seen guys wield a pile of files to do work I only thought could be done by a mill so to each their own. By the way, take care not to overheat the lips when sanding.
This is my 2×72 Esteem grinder (belt sander) and it’s simply wicked. I bought it after my dad passed away and it whipped the extra material of the mags with speed and ease. Because the work platform is trued to the belt’s backing plate, I found I could trim the mags in one pass by putting the flat edge on the platform and feeding the magazine into the belt to remove material. I think it’s an 80-ish grit belt and it left a burred edge that definitely needed cleaning up. Note, these big grinders run cool due to the long belt and a variable speed drive that let’s me dial down the speed so I don’t burn the metal. You don’t want to hurt the heat treat so an easy gauge for novices is to not let your work piece get hotter than you can touch. You can let it air cool or have a dunk tank – just be sure to spray it with WD40 later to displace the water.
Slow down removing material as you get close to the line. Double check all of your measures and scribed lines. It is way easier to take more metal off than to remove too much.
With the coarse cut made, you need to go in and remove all of the burrs and round the sharp steel edges over. I used a specialty flap sander known as a “sanding mop” at 180 grit and then a rubber polishing cone in my Dremel.
I used a type of flap sander known as a sanding mop to do the initial deburring but you could use small files, stones, or whatever you are comfortable with. Here, I am using a rubber polishing bit to clean things up and ensure there are rounded edges on all of the newly trimmed steel.
Last, blow out the tub, wipe it out and clean the body too. You don’t want abrasive materials jamming up the magazine or the pistol. After that, reassemble the magazine and check the action of the follower and that everything seems ok.
After blowing out the tubes. I used a purpose built Arredondo HiCap Mag Brush to ensure the insides of the tubes were clean.
Las step was to function test the magazine with at least three dummy rounds. Four would be even better because you will test feed from both directions as the follower pushes the rounds up from the bottom of the magazine.
Feed Lip Measures
I measured the first few magazines I converted and they were fine so I stopped checking every mag unless I ran into a problem during function testing.
Feed Lip
RIA Mag
MGP164015B
Modified
Length
0.482″
0.599″
0.436-.438″
Front Gap
0.356″
0.354″
0.362-0.364″
Back Gap
0.340″
0.364″
0.336-0.370″
Measures are approximates. I had one RIA mag and measured two MGP164015B mags and averaged the measures. The length was a challenge as I had to make a judgement call as to where the actual front part of the lip was at given the angle. The length was measured from the back forward. I measured three modified mags after fine tuning. Each mag was tuned until it reliably fed.
Fine Tuning
Trimming the lips gets you in the ballpark but more work needs to be done. Every magazine was deburred and had all top surfaces deburred and polished. The inside of the magazine was treated with Dupont Teflon. The feed lips were adjusted until four rounds fed reliably into my RIA 52009 10mm pistol. The final round was tested four times.
To tune the feed lips, use snap ring pliers or chandelier chain pliers to open the feed lips ever so slightly and test. In general, it does not take much. Your goal is to get the bullet pointed towards the chamber as much as possible. Go slow and test – it really does not take much to spread the lips and change the angle.
This fine tuning gets you in the ballpark – you then need to actually go to the range and shoot them to see if any final tuning is needed and then brings us up to the last topic – you need to number your mags so you can keep track of what mags are having problems so you can work on them.
Note: I purposefully fit the mags to use the supplied Mec-Gar followers that can lock the slide open. There are aftermarket Arredondo followers that are really nice and are angled to point the round more at the chamber. The downside is that they don’t lock the slide open – while a person in competition doesn’t need that, I do like to know when I fired the last round.
A lot of feeding problems are actually caused by the magazine – notably the feed angle and that is controlled by the feed lips and the follower. The feed lips can get bent when they are dropped, sat on, or whatever. The follower is plastic and will wear over time – not fast, but it will wear.
You need to put a unique number on each magazine so you can track the ones that are having problems and need some tweaking. I’ve seen guys use engravers, paint pins and stickers. What you use is up to you. I’m currently using waterproof stickers on my mags.
I am using waterproof stickers to track my mags. You could use an engraver or paint pen. I find that permanent markers rub off way to easy. The paint pens are a bit better. The method that holds up best is an engraver if you are good enough at it.
Conclusion
I now have my original RIA magazines and a nice back up selection of mags for hunting, going to the range, bear protection, etc. How did they turn out? So far, so good at the bench. I expect most will do really well at the range as well and I am waiting for a chance to go.
Left is the original RIA mag, in the middle is a converted mag with a Dawson +200 base plate and the mag on the right is also a converted unit but with a +300 base plate.
This is the mag well on the high cap pistols. It’s big and I really like it but it really does mean that you need to have a longer baseplate and just a piece of metal like the Para P16 originally had. You can make your own by adding something to the Para plate or buy an extended plate such as the ones from Dawson Precision that I use.
Pistol with the original RIA mag fully inserted. It is almost flush with the bottom of the mag well.
This is the +200 Dawson base plate. It stick out far enough that I can firmly seat / smack / beat the mag into place if I need to. Not much to grab onto though but all of the mags easily drop free – at least during bench testing they do.
The .300 base plat stick out a tad further. Dawson’s number is the length in tenths of an inch – 0.100, 0.200 and 0.300. I ordered some 0.100 plates but they haven’t arrived yet. They will likely be very close to the polymer plate that RIA has on their mags.
I figure there must be guys like me who have one of the RIA high cap .40 or 10mm pistols who want spare mags and hope this will help them out.
6/29/2021 Update: Folks, I have converted a ton of mags now so if you order, I want you to know I have the process working smoothly. My biggest problem right now is finding mags – everyone and their brother is sold out of mags – it’s crazy.
4/1/2021 Update: Added dimensions for the modified mags and info on fine tuning.
3/22/2021 Update: I took them to the range and they worked great with both Ammo Inc 180gr TMC ammo and a variety of Underwood HPs.
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