Tag Archives: Alexander Arms

The Fastest Way To Convert Aluminum 5.56 AR Magazines For Use With .50 Beowulf

Back in 2018, I documented how to convert a basic aluminum AR magazine using a Dremel and a small drum. With the new Alpha ‘Wulf build, I made four new ones real fast using a slightly new method.

With the Alexander Arms (AA) .50 Beowulf DIY Upper comes one actual Beowulf magazine built to AA’s specifications by E-Lander Magazines of Israel. This gave me a chance to see what they did differently to support the ‘Wulf and it comes down to a relief in the front of the otherwise normal AR magazine. This allows the shoulder of the cartridge to pass by without hanging up on its way towards the chamber. Everything else appeared the same in terms of the feed lips and the follower.

E-Lander of Israel makes the Beowulf magazines for Alexander Arms. One is included with the DIY Upper Kit.
This is the top front of the E-Lander magazine. Note the notched out area. On a normal AR magazinet his goes straight across,

So, armed with how basic this was, it immediately hit me that a flap sander could make a quick angled surface faster than the drum mag. So, I loaded up a 3/8″ 120 grit flap sander with a 1/8″ shank into my bench rotary tool.

The magazines I convert are D&H 5.56/.223 magazines that Palmetto State Armory sells. They are reliable and well made plus they are very affordable with sales prices starting around $8.99 and normal price around $12.99 for buyers in a rush. They also have regular combo deals such as a case and seven mags for $89.99. You have to love PSA’s deals. Click here to see what they have.

The first step is to remove the floor plate of the magazine. On these D&H magazines from PSA, I just use a screw driver to lift the floor plate for the tabs to clear the magazine body. Pull the floor plate off while trapping the magazine spring. Remove the floor plate, spring and follower so they are out of your way.

I slide a small screw driver between the magazine body and the bottom plate to then lift and remove the plate from the magazine. Note, the magazine spring will come fling out.
See the tabs/ridges stamped in the floor plate? That is why you need to use the screw driver to lift the plate so those tabs can clear the magazine body.
Any rotary too will use. This is my benchmounted unit that I use on grips and what not, Any Dremel or other rotary tool would work.

So you basically use the flap sander to to cut a ramp on the inside edge of the magazine. You do not need to replicate the notch – just use the flap sander to quickly remove the material.

The left magazine is an original unmodified magazine. The middle has the ramp cut and the right unit has been reassembled. Be sure to blow out the mags before reassembly.

Using the flap sander can get the job done in 30 seconds or so – it’s literally that fast. Be sure to blow out the magazine bodies to remove all of the grit before you reassemble them. Failure to do so may cause you problems later either with the magazine failing or getting into the rifle.

The final step is to test each magazine to make sure it feeds properly. Load two rounds to test chambering in a safe place with the muzzle pointed in a safe direction. Never take a risk.

That’s all there is to it. You can convert a magazine faster than the time it took you to read this post. I hope it helps you out.

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 [email protected]. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Building A .50 Beowulf – Part 3: Observations On Building the Upper, Lubrication and Vortex Strike Eagle

So things were going together really well for the Alpha ‘Wulf and no, I’m not going to say “and then I hit a snag.” I was impressed by all the parts so far. In the last post I talked a bit about the lower assembly and the upper parts I picked in addition to the Alexander Arms DIY upper. In this post, I’m going to share a few observations on the handguard, brake and lubrication.

The MI Combat Handguard

I don’t recall exactly when I first found out about the Midwest Industries (MI) Combat series of rails but used one this past Spring when I built a 10.5″ 5.56 AR Pistol. The biggest thing I like is the barrel nut. Now that may sound like a crazy thing to get excited about but there’s a reason. Look at the MI Combat barrel nut – it is a knurled circle with a groove in it. The reason this matters is that the handguard can rotate however it needs around the nut and is secured by a steel key and clamping onto the knurling. If you don’t have this kind of a design, you need to use shims or do some combination of filing and potentially crazy levels of torque to get the handguard’s top Picatinny rail to “time properly” (or align properly) with the rail on top of the upper receiver and also to get the gas tube to pass through into the upper receiver’s bolt carrier channel. PSA has good prices on them so click here to see what they have.

This is the MI barrel nut that the combat rail uses along with a small tin of AeroShell – 33MS/64 Extreme Pressure Grease, MIL-21164D and an acid brush to apply it.
The key shown just to the of the screws is part of the cool design. The small nub sitcking out goes into the groove to lock the handguard into position front to back. The two screws go into the handguard to both secure the key and to provide the clamping pressure onto the knurled surface of the barrel nut – it is a very elegant and effective design.
Here the key is inserted and the two screws were just inserted. They have blue Loctite on them and will be torqued down to 55 inch pounds.

I do have a few tips for you to bear in mind. Bear in mind the Beowulf has a kick. Bring everything to a torque spec and use Blue LocTite 242 or 243. Both are “medium” formulas that can be readily disassembled with the right tools and 243 adds a bit better oil resistance. I’m moving to 243 as I use up my 242 supply but it’s up to you one which you want to use.

Install the Barrel Nut First

First, just back out the set screws and the low profile gas block will slide right off the barrel. You need it out of the way to install the barrel nut.

Next, secure the upper assembly in a vise. You will need to use a fixture to hold the upper when you do this. Absolutely do not use your lower to hold the upper. You will bend things. My tool of choice now is the Magpul Barrel Extension Vise (BEV) Block. It very securely holds the upper by engaging the barrel extension. It’s the best tool I’ve found and PSA carries it.

This is my BEV Block along with a spare bolt carrier I use to secure it into the barrel extension akong with a cross pin.

The following is the approximate process for installing a barrel nut:

  • Degrease the receiver threads and the barrel nut. The Combat rail comes drenched in oil.
  • Apply the AeroShell – 33MS/64 Extreme Pressure Grease, MIL-21164D to the receiver’s threads – I use an acid brush to get an even light coat.
  • Torque the barrel nut down to 35 foot pounds (yes, this is foot pounds unlike the gas block) using the spcial MI torque plate they provide and your 1/2″ torque wrench
  • Loosen the barrel nut – ideally not with the torque wrench to save it from wear and tear.
  • Torque it again to 35 foot pounds again and loosen it again.
  • Now, this is the final torque – take the MI nut down to 35-80 foot pounds. I took mine down to 40 foot pounds and called it even. Why the huge range? Well, if you have an old school barrel nut, you may need to torque it quite a bit to get things to align but in our case we just need to apply enough torque to call it even.

Installing the Gas Block

The gas block set screws do have a torque spec if you hunt long enough. Alexander Arms (AA) does not provide it in their general purpose Beowulf manual or instruction sheet that comes with the DIY upper. People cite 25 inch pounds (not foot pounds) with one drop of 242 Loctite per “echnical Repair Standard (TRS) SOFWEP-07-G12P-00032-00 Rev 1 Appx H” that I have yet to locate a copy of that manual. With that said, that is exactly what I did but I used the 243 formulation of Loctite.

Also, AA has done all the machining and used centering set screws to go into the divots in the barrel. You do not need to worry about needing to measure a set back from the barrel’s step lip – just slide the gas block on, put a drop of Loctite on each screw, carefully align the tube and then torque down the screws.

One drop of 242 or 243 Loctite and then torque each set screw to 25 inch pounds – I used my Vortex torque screw driver to tighten mine down.

Timber Creek Heart Breaker Brake

Based on my first Beowulf, it’s very critical to get a good muzzle brake. If you want to reduce felt recoil, the best things you can do in order are: 1) install a good brake. 2) have a good recoil pad 3) make the rifle heavier. Now, I do all three plus I use a hydraulic buffer that helps a tad but a good brake is absolutely critical. For me, it is absolutely my first priority and I knew I wanted to use the Timber Creek Heart Breaker again.

Here’s the Heart Breaker from the side and you can immediately see the heart shapes that give the brake it’s name. Also note the jam nut behind the brake.
A view from the top with the ports shown. The bottom does not have ports – just the top to reduce climb.

The AA barrel uses a unique 49/64-20 RH thread. If you are not using an AA barrel, confirm the thread before you order a brake.

To install the brake, I run the lock nut to the bottom of the thread and then thread the brake on as far as it will go, rotate it into final position and then tighten down the lock nut to 20 foot pounds using a crowsfoot head on my torque wrench. I’ve not used Loctite but you can if you want extra protection – I would still go with the medium strength 242 or 243 formula.


To lubricate the whole rifle, I use SuperLube grease and oil. I know it sounds like an infomercial name but it actually works really good. The base is a synthetic lubricant with “micronized PTFE” (think tiny Teflon particles) added in.

If it slides, I apply a light brushed on film of Superlube grease. If something rotates, I use drops of the Superlube oil. Now some folks will disagree with me and go with all CLP or LSA or some secret blend they like – fine. This is just what I do.

After lubricating it, everything was nice and smooth plus I did function testing to make sure everything was working properly in terms of the selector, disconnector, trigger, etc. In fact, Brownells has a nice page on attaching the upper to the lower, lubrication and function testing.

Vortex Strike Eagle 1-6×24 Optic

Before I pick an optic, I think about how the firearms it is going on will be used. For the Beowulf, it will be hunting and target shooting typically within 100 yards and maybe out to 200 max plus low light situations might well occur.

Armed with that, I decided to use a Vortex Optics Strike Eagle with a 1-6 power magnification, a 24mm objective and a lit reticle. My eyes aren’t so red hot any more so I knew I would need some basic magnification while still having a wide field of view at 1x. Also, I am a huge fan of Vortex due to their quality and no BS warranty. If anything goes wrong with a Vortex optic, they will repair or replace the unit and not run you ragged.

I also opted for a quality offset Vortex mount. You need a solid mount and not something that is going to constantly shoot loose or break under strain.

How Does It Look?

I haven’t had time to take it to the range yet, but am definitely liking how it turned out. The Alexander Arms DIY upper was great to work with as were the Geiselle trigger and MICombat handguard. The PRS stock helps balance out the rifle and adds weight plus the great recoil pad that comes with it. Now, If I can just find some time to go to the range 🙂

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 [email protected]. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

My apologies but I have no way to filter out items that the vendors have sold out such as ammo. For example, most places sell out of the ammo fast but you should keep an eye on both Midway USA and going to Underwood Ammo directly – Underwood makes very good ammo by the way. I usually run Alexander Arms ammo but they are sold out most places and while you can place an order directly, you will need to wait quite a while for it to be made and shipped.

Building A .50 Beowulf – Part 2: Observations On Building the Lower and Upper Parts

As mentioned in the last post [click here] – building a Beowulf is pretty much like building any other AR15-class rifle. I put it that way because the AR10s are different and the Beowulf uses the AR15 platform with the notable exception of an enlarged ejection port. The modular capabilities of the AR platform are what make it versatile.

Lower Build Comments

First, I’d like to point out I ran into one small snag with the Spike’s lower. The detent spring and pivot pin hole had some kind of debris in it or maybe a bur. I had to chase it to clean it out. Other than that, it went great.

Normally, installing the front pivot pin is pretty easy with a tool like the one shown that helps you trap the deternt and spring. Because of somethign obstructing the hole inside, the deternt didn’t push down and actually scored my relativelyt soft tool. So, I chased the hole and it installed no problem. Two lessons learned – #1 chase the holes first. #2 – I decided to mve to a stainless steel install tool.

My second comment is about the Magpul PRS Gen 3 stock. Wow. It is really cool. First, I went with the rifle buffer tube because I assumed the Gen 3 needed it – in fact, it does not. When you look at the Gen 3, it has a modular front nose that comes apart just behind the front swivel hole. It comes from Magpul all set to use a carbine buffer tube! Now it is a fixed stock and will not adjust but you do not need to change tubes. Had I known that, I would have used a carbine tube to avail of all the different buffers that are out there.

12/28/2020: I am tinkering with the combination of buffer and buffer spring. Click here for a post about them.

By the way, the PRS is an expensive stock and it pays to watch for sales. Also, this is specifically then third generation model – you will see older stocks pop up on eBay, etc. The older ones will not have the really thick recoil pad or the ability to use a carbine tube. Here it is for sale at PSA.

The PRS Gen 3 is sweet! Note the really thick recoil pad and modular front end that can accomodate either a carbine buffer tube or be swapped out to support an A2-style rifle buffer tube. This gives some nice flexibility.
The carbine modular front end is to the left and the rifle is in the right.

By the way, I took the time to torque down everything including the rifle buffer tube in this case. The Magpul wrench makes it real easy to bring the nut down to the torque spec of 35-39 ft lbs.

Screwed in the rifle-length buffer tube with just a bit of moly grease on the threads.
Used the Magpul wrench and a toruqe wrench to bring the receiver extension / buffer tube down to a 35-39 foot pound torque spec. In general, I set my wrench at the lower end of a scale unless there is something very specific.

I think I will stick with the basics going forward. In other words, I’ve tried extended head pins, bolt catches with giant heads, ambidextrous selectors and in the end, I find I really don’t need them. The takedown pins and controls are all mil-spec in this build.

Upper Build Parts

The upper is the actual DIY (Do It Yourself) upper from Alexander Arms and they do all the engineering and machining for you. I also need to point out that it is really well done. I have zero complaints on the fit or the finish.

The DIY kit includes the upper receiver, bolt, carrier, charging handle, barrel, and the gas tube has already been installed in the lowe-profile gas block. The unit arrives assembled including their already divoting the barrel for the two gas block set screws. What you will need to do is to add your own barrel nut and handguard plus whatever you want to do for a muzzle brake. The DIY comes will a thread protector for the 49/64-20 right hand (RH) threads.

Here’s the upper fresh out of the box.
They already drilled the divots in the barrel an are using centering set screws so you can just remove the gas tube, install your barrel nut and then slide the gas block back on and tighten it down.

Folks will tell you I am either particular or eccentric (maybe both) when it comes to my builds. I knew there were some parts I wanted to use on this upper:

  • MI Combat 15: M-LOK handguard. These are very nicely done with all edges beveled plus I like the barrel nut they use. It simplifies aligning the handguard and receiver rails. Also, I really like having the flexibility to add rails or accessories where needed while having a slim profile where I don’t. Keymod has pretty much died out and M-LOK seems to be the lead attachment method now.
  • BCM Mod 3 charging handle greatly simplifies working around optics to charge the rifle.
  • Timber Creek Heart Breaker muzzle brake. This is an excellent choice for taming the Wulf. I was so impressed by it on my first rifle that it was my automatic choice for this second rifle.

Upper Build Instructions

A Beowulf upper is very much like any other AR with the exceptions of no ejection port cover and a screw on gas tube block.

Here are some third party resources on assemblign AR uppers in case you are interested:

Here Are Some Videos For Building Uppers

I always like to combine stuff I read, like the above, with videos I can watch. I always pick stuff up both ways and think the two perspectives are very valuable. With that said, here are some build videos.

Brownells also has a ton of training videos online that cover building the AR-15 overall. If you click here, you can then select whatever videos you want to watch.

Closing This Second Post

Hopefully this post gave you some insights into what I actually did with the lower and thoughts on the upper. In the next post, I’ll share some of my observations from when I actually installed the handguard, brake and ortex Strike Eagle Optic.

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 [email protected]. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Building A .50 Beowulf – Part 1: The Alexander Arms .50 Beowulf 16″ DIY Upper Kit and Lower Receiver

Okay, so I built my first .50 Beowulf rifle in 2018, spent a lot of time planning out the recoil mitigation and documented the adventure – click here for the post. At any rate, I sold it to move on to fund other projects but ran into a problem – I missed the ‘Wulf. There are some bragging rights when you say you have a .50 caliber rifle even when you explain it’s not the .50 BMG round. So, I decided to build another one and make it pretty unique. It’s the Alpha, or the dominant Wulf in my mind.

The first thing I want to point out to folks is that the 12.7x42mm is the generic designation of the .50 Beowulf round and is mainly used by firms who don’t want to get into intellectual property issues with Alexander Arms (AA). If you look on Gun Broker and do some searching with Google you will turn up tons of listings for complete 12.7x42mm uppers starting just over $300. … Let me put this delicately – I would recommend that you avoid them. You will get what you pay for either in terms of performance out of the box or over time. If you do some searching you will read that I wasn’t the only buyer who had issues with Radical Arms uppers for example because of the wrong bolt being used.

If you do buy a cheap 12.7×42 upper, I’d recommend you test it right away before the warranty expires. I’m sorry – I just don’t have much faith in them.

Started With an AA .50 Beowulf DIY Upper

This time around, I decided to use an actual Alexander Arms (AA) upper and not screw around with cheap stuff. The only problem was that I wasn’t really sold on the handguards of their complete units. That and the prices were a turn off the last time. As I looked down the AA page, I saw they now sell a “.50 Beowulf Upper Kit DIY” that had everything except for the barrel nut, handguard and brake of your choice. They have both 12″ and 16″ barrel versions of the kit. As much fun as a 12″ howitzer would be, that didn’t interest me as much as building a new rifle using a 16″ barrel.

Here’s the 16″ DIY kit from Alexander Arms. It is very nicely done. Fit and finish were excellent. The manual is for their Beowulf rifles in general and doesn’t help much with the assembly. They do give a bit of guidance with a sheet of paper that comes with the upper. A person new to ARs will need to research how to assemble an upper – I’ll give a quick summary of what I did in this post.
Here’s the upper receiver assembly – good finish. No ejection port door as the port is enlarged. I thought about making one but I really don’t need the cover.
This is their low profile gas block. All the machining work has been done for you. They already fit and pinned the gas tube plus dimpled the barrel for the two set screws on the gas block to center on.
They do include a muzzle nut over the threads. AA threads their barrels 49/64-20 RH for brakes and you definitely want a brake for a ‘Wulf. A brake is essential for reducing felt recoil – weight of the weapon and a good recoil pad help as well.
A view of the bottom of the upper – again, want to point out the nice fit and finish. Nothing gritty like you feel with cheap parts – these are very well done. They need lubing certainly but that is to be expected. Cheap parts can be so bad sometimes that it feels like two pieces sandpaper rubbing together. Everything in the AA upper slides/moves smoothly.
Here are the two set screws for the gas block. Mine were very lightly tightened and thus easy to remove. I’ll mention this again later but when you install use medium blue Loc-tite (formula 242 or 243 if you want the numbers) and tighten the set screws to 25 in/lbs each.

To sum up the AA upper, they make this build real easy. For me, building an AR is like building with Lego parts from different kits to make something unique, which was exactly my plan with this new ‘Wulf. Next, I am going to skip the upper for a minute and tell you what I in terms of the lower receiver. Why? Well, I’m a creature of habit and always build the lower first and then the upper.

An Overview of The Lower and Parts Used

The stripped Spikes Tactical lower I picked is pretty cool! You have the Crusader Cross up front and then look at the selector markings – Pax Pacis (Peace, Truce, treaty)), Bellum (War) and Deus Vult (God Wills).

I thought about using an existing AR lower from another rifle but I decided to build one from scratch. In case you didn’t know it, a Beowulf upper is actually designed to work with any 5.56 AR lower without any modifications being needed to the lower itself – same trigger, buffer, etc. The magazines are slightly modified but we’ll return to that later. So here are the parts details for the lower assembly:

Building the Lower

A Beowulf uses a standard lower so there really isn’t anything special that you must do. Thus, I’m not going to do a complete part by part instruction just for this rifle. Here’s a write up I did a while ago while building an AR pistol, which is pretty similar other than the use of a brace with a pistol vs. a stock with a rifle:

I always found having multiple perspectives to draw on can help. Here are two excellent written resources for you if you are new to building lowers:

If you would like to see videos of the AR build process, Brownells also has a ton of training videos online that cover building the AR-15 overall. If you click here, you can then select whatever videos you want to watch.

Closing This First Post

Okay, so you have an idea of the Alexander Arms DIY .50 Beowulf Upper upper I bought and the lower parts plus assembly. In the next post, I’m going to give you some tips/observations that I had when assembling my lower. I’ll add a link to the new post here as soon as it is complete.

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 [email protected]. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.