We Make Custom 10 Round Magazines for Rock Island FS A2 10mm and .40S&W High Cap Pistols

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.

Click here to go to the section of our online store that has all of our current 1911/2011 magazines and related products.

I’m not going to re-invent the wheel – click here for blog post on the MGP164015B conversion. It’ll give you a good idea of what was done and is the same work that needs to be done with these 10-round magazines.

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.

I hope this helps you out.

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