.300 BLK pistol done.

Direct Assault

Sergeant
Full Member
Minuteman
Sep 8, 2011
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Finally finished my pistol. I ended up going with NiB just to see that it was like. This one is just for fun.
Mega NiB billet recievers.
KAC urx 4 10 inches
KAK super big extension with Sig TAC brace.
Rainer arms ultra match 8.5 barrel 1x8
Rainer arms BCG and raptor charging handle.
DD lpk
Noveske kx3
KAC micro sights

The balance is nice. Maybe a little nose heavy. Can't wait to shoot it.

 
I went with an 8.2" Noveske on mine. It's a super compact rig. 21.5" with brake. I built a 12" upper with carbine length gas as well just to compare sound reduction, recoil impulse, etc. and mess around with loads. I ended up keeping the 8" and run either the 185 TTSX and or 194 gr Lehigh ME with adj gas. Got the report down to about 1 1/2 decibels of the 12" carbine when suppressed. This is next to an 11.5" 5.56. Ridiculous, dare I say it's borderline too short. Never thought "too short" was even possible.


 
I went with an 8.2" Noveske on mine. It's a super compact rig. 21.5" with brake. I built a 12" upper with carbine length gas as well just to compare sound reduction, recoil impulse, etc. and mess around with loads. I ended up keeping the 8" and run either the 185 TTSX and or 194 gr Lehigh ME with adj gas. Got the report down to about 1 1/2 decibels of the 12" carbine when suppressed. This is next to an 11.5" 5.56. Ridiculous, dare I say it's borderline too short. Never thought "too short" was even possible.




That thing is really sharp man. I need some of those rail scales! They look great on the urx 4
 
The rail scales are perfect. They add about 3.5mm and feel like a grip with finger grooves. Also do a great job reducing any heat coming through the handguard. The one downside is the $70+ for 3 4" scales. Hopefully the 2"ers are a little cheaper...
 
I got mine from Engage Armament in Maryland for $410 shipped and it got to me in three days. Their # is 301.838.3151 or you can shoot a note to Ryan at [email protected].

A few things to note, the stocks they have include the proprietary bolt carrier that has a buffer machined into the rear and a spring made specifically for the set up.

The right side bar does not have multi-position adjustment for length of pull. It pulls back and locks only at fully extended position.

If you have a lower with a right side bolt release, like the Seekins for example, the right side bar must be cut to allow the stock to fully collapse.


The spring and mag release button used as the adjustment mechanism is poorly made. I switched the spring out for a longer 308 mag release spring and used a spare Seekins magazine release button instead of the std plastic one as it protrudes just a touch more and ends up making a huge difference in the ease of adjustment.


The left side bar has a set screw machined into the end to act as a stop and somewhat as an anti-wobble mechanism. Problem is there is still significant wobble. I drilled, tapped to rethread using a 3/16ths that works perfectly. Pic is of the gaps present with factory set screw.


The term "cheek weld" should not be used in the same sentence as this stock. If you're used to having one this unit will take some time to get used to as there is literally zero cheek weld to be had. It's also nearly a half pound (7.6 ounces to be exact) heavier than the LWRC UCIW. All parts in each lower are the same. Without stocks they are with .8 ounces of each other. Adding stocks and using the same upper on each lower (swapping carrier obviously on the NEA) the NEA-equipped rig is noticeably heavier. The UCIW does give up 1.3 inches in length when fully collapsed. That said, I do feel the UCIW is "shootable" while fully collapsed if one had to. That is not the case for the NEA - at least for me.



The UCIW has a buttpad 4.65" tall by 1.95" wide vs the NEA that is 3.4" tall but only 1.25" wide. Seems like you're jamming a dowel rod into your shoulder. It's things like this that effect the "shootability" of the rifle that Im really conflicted about. If the design wasn't so damn cool it would already be on Gunbroker or in the classified section.


Compared to the LWRC UCIW kit (that runs $129) I'm not sure the NEA is worth keeping. The jury is still out. I called NEA to get the multi-position adjustment bar to replace the current one to see if I can make it at least somewhat comfortable to shoot about halfway through the adjustment range. I'm also messing around with some of Slash's UCIW springs to see if I can't get this running how I like, see how well I can control gas blow back, dwell time and just go from there.

FWIW, I did throw an 8.5" .458 SOCOM on this and swapped the NEA factory spring with a UCIW XP spring from Slash's heavies. Thing ran like unicorn butter!
 
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I almost forgot. My original intent was for this stock/carrier to ride my 5.56 which I've built on the San Tan lower. I then tried a KAC. No go with either as a result of the flush cups milled into the rear of the receiver right where the adjustment bars on the NEA pass by. Unless you're willing to file those down to fit flush (and render them unusable) the NEA will not fit.
 
Wow, that's a ton of info. Thanks! I'm interested in putting it on my 300blk pistol build once I get out of Kommiefonia and I can register it as an SBR. If you decide you want to get rid of it, let me know and maybe we can work something out. I wouldn't be so much worried about cheek weld since mine will only have a reflex on it. I'll be down in the swamps shooting hogs with it so maneuverability is a big deal. It's going to have an Aero precision lower on it, and I will probably mill some extra slots on the tube to make it adjustable for LOP. Long story short, that thing's BA man. Well done for you and the OP. Sorry for derailing the crap out of your thread brother.

And now, back to your regularly scheduled programming.
 
Your build does look awesome. Can't wait to hear how she shoots. It's definitely making me reconsider my 8" barrel for a 10". I'm planning to use a Aero Precision COP upper with a matched pistol lower. I'm just not sure what the length of the hand guards are. I'm going to be using the same muzzle device on mine, and I'm worried it will be completely recessed in the hand guards with an 8" barrel.
 
Your build does look awesome. Can't wait to hear how she shoots. It's definitely making me reconsider my 8" barrel for a 10". I'm planning to use a Aero Precision COP upper with a matched pistol lower. I'm just not sure what the length of the hand guards are. I'm going to be using the same muzzle device on mine, and I'm worried it will be completely recessed in the hand guards with an 8" barrel.

My build is in fact an 8.5 inch. It has a 10 urx 4 rail. 8.5 inch barrel. And it shoots great! Super smooth and without hang ups. I was surprised at the accuracy! Im impressed with the .300 and now I want to build another one for the wife because she shot my damn gun more than I did!
 
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I may eventually SBR my pistol but who knows. The wait time would kill me.

Correct me please if im wrong, but I was told that I wouldnt have to give my pistol up while waiting for the stamp.. I have the Tac brace also and im not going to lie, everytime I shoot I wish I had a adjustable stock. Just bugs the crap out of me. Better than a pistol with no "forearm" brace, just isnt the same.

Love that rail/pig combo! Plan on ever supressing it?
 
My build is in fact an 8.5 inch. It has a 10 urx 4 rail. 8.5 inch barrel. And it shoots great! Super smooth and without hang ups. I was surprised at the accuracy! Im impressed with the .300 and now I want to build another one for the wife because she shot my damn gun more than I did!

Also, have you shot for groups at all? I have a 9" AAC barrel and mine seems to be around 2.5"-4" on average at 100 with just a trijicon reflex with a 4 moa dot standing against a post in my backyard. Just wondering, to be honest I dont even know what to expect. Ill take it!
 
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Correct me please if im wrong, but I was told that I wouldnt have to give my pistol up while waiting for the stamp.. I have the Tac brace also and im not going to lie, everytime I shoot I wish I had a adjustable stock. Just bugs the crap out of me. Better than a pistol with no "forearm" brace, just isnt the same.

Love that rail/pig combo! Plan on ever supressing it?

You have to get it engraved or engrave it yourself as a registered SBR. You do not have to give it up but you can't build it as a SBR until you pay the fees and wait the time. Don't even buy the parts to SBR it until ALL of the paperwork is done. There are very serious rules and even more serious consequences if you break them. Most people build a pistol while they wait for the nfa approval because it take such a long time. All I have done is safety check it at close range so no groups yet but so far I'm really liking it. I would love to suppress it of course but that's another stamp and another waiting period.
 
Also, have you shot for groups at all? I have a 9" AAC barrel and mine seems to be around 2.5"-4" on average at 100 with just a trijicon reflex with a 4 moa dot standing against a post in my backyard. Just wondering, to be honest I dont even know what to expect. Ill take it!

Also do NOT get your lower engraved as a registered SBR and take it home and put your PISTOL back together. That's a mistake. Buy a stripped lower have your ffl take it in as a "pistol" or "other".( You can make a pistol a rifle but not the other way around.) Once you have your new stripped lower send it off to be engraved and use its serial number on the nfa paperwork. Then wait and wait. During the wait you can shoot your pistol as it is now. When you get the new stripped engraved lower back from the engraver and your stamp is approved build the lower as a rifle lower and put your shorty upper on it. Boom legal SBR.
 
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I got mine from Engage Armament in Maryland for $410 shipped and it got to me in three days. Their # is 301.838.3151 or you can shoot a note to Ryan at [email protected].

A few things to note, the stocks they have include the proprietary bolt carrier that has a buffer machined into the rear and a spring made specifically for the set up.

The right side bar does not have multi-position adjustment for length of pull. It pulls back and locks only at fully extended position.

If you have a lower with a right side bolt release, like the Seekins for example, the right side bar must be cut to allow the stock to fully collapse.


The spring and mag release button used as the adjustment mechanism is poorly made. I switched the spring out for a longer 308 mag release spring and used a spare Seekins magazine release button instead of the std plastic one as it protrudes just a touch more and ends up making a huge difference in the ease of adjustment.


The left side bar has a set screw machined into the end to act as a stop and somewhat as an anti-wobble mechanism. Problem is there is still significant wobble. I drilled, tapped to rethread using a 3/16ths that works perfectly. Pic is of the gaps present with factory set screw.


The term "cheek weld" should not be used in the same sentence as this stock. If you're used to having one this unit will take some time to get used to as there is literally zero cheek weld to be had. It's also nearly a half pound (7.6 ounces to be exact) heavier than the LWRC UCIW. All parts in each lower are the same. Without stocks they are with .8 ounces of each other. Adding stocks and using the same upper on each lower (swapping carrier obviously on the NEA) the NEA-equipped rig is noticeably heavier. The UCIW does give up 1.3 inches in length when fully collapsed. That said, I do feel the UCIW is "shootable" while fully collapsed if one had to. That is not the case for the NEA - at least for me.



The UCIW has a buttpad 4.65" tall by 1.95" wide vs the NEA that is 3.4" tall but only 1.25" wide. Seems like you're jamming a dowel rod into your shoulder. It's things like this that effect the "shootability" of the rifle that Im really conflicted about. If the design wasn't so damn cool it would already be on Gunbroker or in the classified section.


Compared to the LWRC UCIW kit (that runs $129) I'm not sure the NEA is worth keeping. The jury is still out. I called NEA to get the multi-position adjustment bar to replace the current one to see if I can make it at least somewhat comfortable to shoot about halfway through the adjustment range. I'm also messing around with some of Slash's UCIW springs to see if I can't get this running how I like, see how well I can control gas blow back, dwell time and just go from there.

FWIW, I did throw an 8.5" .458 SOCOM on this and swapped the NEA factory spring with a UCIW XP spring from Slash's heavies. Thing ran like unicorn butter!
Jason,
Where the stock with no cheek wield would be great is as a dedicated night vision gun. When you are running NOD's on a helmet you don't have cheek wield anyways, so the compactness and coolness would be great for throwing an IR laser on it and rocking out. I am about to do the exact same thing.