AR Dudes: Blackout Pistol Build Help

tt35

tt35

New member
OK so I have an AR Pistol lower I purchased after the 2008 Presidential election. It was just chance that it was marked as a pistol but I'm glad it is now as I just pulled the trigger on a CMMG 8" stripped AR barrel in 300 Blackout. Looking for some help/input. Never assembled an AR before.

Here's the rest of what I have so far:

lower parts kit
pistol buffer tube kit
SBX15 stabilizer
bare upper
bolt and bolt carrier group
pistol length gas tube and pin
LP gas block


I haven't bought a pistol fore end. I think I'd like a free float tube. Any suggestions?
I'll also need another QD FH for my suppressor.
I do not have an armorers tool either. Anything special I should be looking at?

Any other parts I need that aren't mentioned?

Thanks for the help!
 
I'd go with the free float tube, one that's long enough to cover the gas block. No special reason i just don't like the looks of a gas block on the barrel. If you don't want to buy the tools I'll loan you mine. But having all the tools is nice when you decide to change things up a bit.
 
vahunter: Thanks for the generous offer! I guess I should be posting this up in the AR Forum. Duh. Mods want to move it? New thread?
 
Man o Man, you've done it now. You'll be hooked! Might as well buy nice tools the first time. I have a dpms upper receiver block that works pretty well, but if I was buying now I would get this: http://www.brownells.com/gunsmith-tools-...-prod55168.aspx It looks like the cat's meow, allowing assembly without any stress on the upper at all. Maybe someone on here has used one and can comment.

This tool is nice for squaring the face of the upper receiver: http://www.brownells.com/gunsmith-tools-...prod20220.aspx. Probably not necessary on a 300 blk pistol, but you'll want it when you build that 17 cal sage-rat slayer.

I need a new barrel nut wrench myself, and will probably get something like this: http://www.brownells.com/gunsmith-tools-...prod27412.aspx. I have one in the 308 size and it works fine and is versatile.

I would do a ff tube on your pistol, probably a carbine length so it would cover the gas block. Although you may want an adjustable gas block to fine tune it, and would then need access to it.

BTW a buddy and I were out your way 2 or 3 years ago with Duanne shooting rats. We are considering coming out again this year. I scheduled work for May 5th vaca, does that seem like prime time? Could you PM me some details on your shoots?
 
Thanks for all the info, 204! Is an adjustable gas block needed specifically for subsonic loads? I can see that that may be an issue. The barrel is only eight inches long. I'm looking at a 7.2" tube. Does that sound about right?

Here's a link to our guided hunts page. Let me know what other info I can give you. We set up on platforms with individual swivel shooting benches, do a big "field lunch and have a guide with you loading mags, spotting and keeping you on fresh targets. It's a good shoot.

http://no-off-season.com/guided-hunts.html
 
If you were a little closer, you could borrow my upper vice block and armorer's tool. Or if you come to the Nampa/Boise area, drop me a PM and we can do it here at the house. Takes about 10 minutes to get the barrel and rail on. Depending on which can you have, I'd go with a Seekins MSRv2 12 or 15" rail depending on how long your can is. Which can do you have? The ID of the Seekins rail is large enough to fit most cans under the rail and it would look like this, only a little shorter.

Here's a picture of my 300 upper with a 15" MSRv2 rail on my SBR. My can is an AAC 7.62 SD and there's enough room in the slots to use a tongue depressor to spin the can off.
desktop300bo_zpsf188ae99.jpg
 
Thanks again for the kind offer. I may just take you up on it if I don't have this done before I get your direction. I am building this for my YHM-3300-ti. It's QD. It's 1.5" dia by 8" long IIRC. I had not considered covering a portion of the can with the handgaurd. That's a great idea. Looks like you could turn yours on and off from the end of the suppressor. No? I do have a source for Seekins. I was looking at Troy since I get a better discount but I'm open. The SBR looks awesome.
 
The AAC 7.62SD has a 51 tooth ratchet type system that locks the can in place. You have to press a tab down to unlock it so it can be spun off. I don't think you'll have that problem with the YHM design and will be able to spin it right off.

I've had a couple Troy rails and still have one on my grandson's 22lr build. I personally think they're a little heavy, around 3oz's heavier without counting the barrel nut. Seekins is 10oz's and that weight includes their barrel nut and I really like the keymod system on the Seekins, no intrusion into the ID of the tube where the rails on the Troy have a nut type system that narrow the channel a little bit. Along with that, on the Troy rail, the modular pieces are nearly impossible to get on and off without taking the whole handguard off.
 
Gotcha. I may just cut down an old knurled aluminum FF forearm tube for now until I see what length and configuration will work best. It should be big enough i.d. for the suppressor. I'm pretty stoked about covering part of the suppressor though. That's gonna work sweet.
 
http://www.predatormastersforums.com/for...323#Post2758323

Here's my build that's kind of along the same lines. IMO an adjustable gas block is an absolute must in the 300 blk. It amazes me the amout of threads that you can read on people who can't get X, Y, or Z to cycle in their gun. All of that could be fixed with a couple quick turns.

I actually have 4 loads that get shot through mine. 110 Vmax, 208 Amax, and then a super and sub load with 150s! All of which cycle. I wouldn't think twice about paying a little more for the SLR block. They also sell a long wrench so you can adjust it when on a gun with a recessed block like mine.
 
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Wow, Brian, that is an amazing piece of kit right there! I'm just kinda piecing mine together as an experiment. It's going to look like a coat of many colors compared to that baby. Would you mind PMing me some of your load data? Have you shot coyotes with the A-max? I was going to order some for mine.
 
Thanks, I sure like it!

No yotes with the subs but I'm 99% sure they would pencil through based on some I've revovered from much harder impacts. I'll be real honest, I couldn't wait to shoot subs when I built this but I now shoot supers the vast majority of the time. They're super quiet and have better trajectory that a rock!

I'm away from home for a bit but when I get back I'd be happy to send my data your way.
 
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