Nov 222019
 

I was having lunch with a friend of mine earlier today and, as it often happens, the conversation turned to guns. We talked about politics prior to that and a fifteen minute conversation was all it took to solve the majority of world’s problems. We had a little time left, so we figured we should tackle something substantially more complicated: what gun he should buy next. He used to be a LEO, so he has had a lot of training with submachine guns. However, now that 300 Blackout is here, I do not see a ton of value in that. A 300 Blackout SBR would be kind of cool. In a perfect world, he would just get a HoneyBadger SBR from Q and be done with it. Except you have to deal with NFA and there is a six month backlog on the gun itself. Next best thing, I figured, would be a Honeybadger pistol. With that approach, you do not have to deal with NFA, but apparently the folks at Q are doing something right, since the backlog for that one, as of today, is around 15 months or so. I am a big fan of Q’s guns, so I checked to see the situation with the Sugar Weasel pistol. That is also backordered. Sugar Weasel uses the same barrel and gas system as Honey Badger, but the stock is a little less sophisticated and the receiver set is essentially mil-spec. It is very slightly heavier than the Honey Badger, but it kicks ass otherwise.

He knows that I’ve built a few AR style guns over the years, so he asked me for some recommendations on what components I would choose if I were building a 300 Blackout AR pistol, so here we are. Generally, I do have one of these that I built a while back and I learned quite a bit about working with a 300 Blackout cartridge in a short barrel from it. However, the one I built has a folding stock from LAW Tactical and Dolos takedown barrel system. Altogether, it is kinda heavy, so I figured it is worthwhile for me to go through the exercise of building another one that is a lot lighter. I think I can shave a couple of pounds off of the weight of the one I have. Ultimately, I am going to go through a set of considerations for a 300 Blackout build that is mostly designed to replicate Q’s Sugar Weasel, given that my chances of finding one are fairly slim with their crazy backlog and all. I will explain why I suggest using Q’s components where possible and why. The links to most of the components I mention are at the very end, although I will link to a few things in the body of the article as appropriate.

Because 300 Blackout was designed to work with both supersonic and subsonic loads, you are dealing with very different gas volumes and pressures. If you also use a suppressor (and you should), you add some additional concerns. Basically, you end up with four distinct possibilities:

  1. Subsonic unsuppressed: least amount of gas volume to work with, so the gas port needs to be the most open in this case
  2. Subsonic suppressed: suppressor adds back pressure, so the gun will cycle with a smaller gas port opening
  3. Supersonic unsuppressed: a little more gas volume, but basically this works at a fairly similar gas port opening as subsonic suppressed
  4. Supersonic suppressed: even more back pressure, so if you use one of the earlier settings you will be overgassed.

With short pistol barrels, tuning the gas system can get kinda tricky and getting it to run reliably with every load is not likely if you do not pay attention.

The sorta standard recommendation from many manufacturers is to pick one scenario and run with that. I appreciate why they suggest it, but I think there is a way to work around it.

In principle, most short barrel 300 Blackout pistols end up using an adjustable gas block. However, switching between gas block settings with most of these is not something you can do on the fly. They are really designed to be tuned once and left alone. The two exceptions to that I am aware of are Collar Adjustable gas block from Strike Industries and Select Gas Block from Seekins. Both of these can be adjusted with a simple tool through the opening in the handguard. I have not used either one of these myself, but I might. I do know people who have used them.

With conventional gas blocks, I like the idea of using them together with a Bootleg adjustable bolt carrier. The bolt carrier has four gas settings, so you can adjust the gas block for the most lowest gas pressure situation (subsonic unsuppressed) and then experiment with the bolt carrier gas settings to make sure everything works with other loads. Unlike the gas block, the bolt carrier adjustment is easily accessible without disassembling the rifle.

With barrels, if I manage to find one in stock, my preference would be to get the Honey Badger barrel assembly from Q. I know I talk about Q a lot, but they make good stuff and there are a couple of things about their barrels that are rather unique. The barrel assembly linked above comes with an adjustable gas block secured by a jam nut and faster than usual 1-in-5″ twist rate. Both are a good idea. Also, their barrel comes with a machined taper up front for mounting a suppressor. If you eventually add one of their direct mount suppressors to the mix, that tapered surface makes sure proper suppressor alignment.

Aside from that, most barrels in the 7″ to 10″ length will work fine, but it worth your time to check with the barrel manufacturer what the had in mind when selecting the gas port diameter. For example, Noveske’s barrel are designed to run with subsonic suppressed and supersonic unsuppressed. There is a good chance that subsonic unsuppressed will not cycle.

I have had good luck with Seekins barrels and I know they can be tuned for all four scenarios. There are, of course others that work well from Odin and Rainier.

Handguards are kinda in the eye of the beholder. There are a lot of them and they mostly work. Some people like long handguards that are virtually as long as the barrel, but with a short firearm like this, I am concerned about accidentally sliding my hand in front of the muzzle. I’d go with something in the 6″ to 8″ length range depending on which barrel you end up using. Q’s excellent 6″ handguard is, naturally, out of stock right now, but it is certainly a good option. Lately, I’ve used handguards from MI for a couple of builds and I think they offer a very good combination of performance and cost.

As far as receivers go, I kinda like somewhat lightened receiver sets like Palouse from 2A Armament. There are lighter ones out there, but they get really expensive. Something like Palouse is not bad, but a standard mil-spec receiver set from someone like Aero Precision is not a bad option either.

Charging handles are also kinda personal. I have had good luck with ambi charging handles from BCM and Raptor, so I would go with one of those.

Lastly, we get to the arm brace. There are quite a few out there now, but I think SBA3 is your best bet for flexibility of use.

Lastly, I want to touch onto the subject of triggers. There very many good AR triggers on the market. If you already have a preference, go with that. Personally, I’d probably just go with Geissele’s SSA or SSA-E and be done with it. It is a know quantity and I have yet to have a problem with one.

 Posted by at 10:12 pm

  2 Responses to “300 Blackout Pistol”

  1. Very similar to what I built. I do think barrel length has an ergonomic factor to consider. Overall length wasn’t my highest priority, so I went with a 10.3″ barrel and 9″ hand guard because that combo had the best shooting ergonomics for me personally.

    The charging handle I would add to your list is the PRI Gasbuster. I originally had a BCM handle and the PRI made a noticeable improvement managing gas to the face when running supersonic suppressed.

    I also went with the SBM4 brace over the SBA3. The SBA3s I have used tend to deform at the shoulder during use. I know there is an aftermarket strap to help with this, but I don’t have experience with it. If you have, I would be interested in your thoughts.

    Thanks for all you do here.

    • You are very welcome.

      Ergonomics are pretty personal. The gentleman I was talking to was trained on the MP5, so he is likely comfortable with shorter guns.

      On SBA3 vs SBA4: I have not had any issues with SBA3, but I mostly shoot subsonics, so perhaps that makes a difference.

      With charging handles, that is a good point about PRI. I have been experimenting with a gas block from Superlative Arms that vents some of the gas forward. That seems to help with the gas issue.