300 BLK Build

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Kanwar88

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Looking to build a 300 BLK AR.
I've decided to go with AAC 9" MPW Upper, but am undecided on the lower.

I shoot left and right handed so I would like ambi controls.
Which manufacturers does this leave me with?
KAC?

Or, is it advisable to get a standard lower and throw on something like the KAC ambi mag release and raptor charging handle and be done with it?

Any advice is appreciated, thanks.
 
Try the latest ATRS lower (and upper/barrel for that matter). Fully ambi, Canadian made.
My 9" barrelled ATRS .300 Blk shoots 10s at 300 meters all day.
 
r_taylor said:
Try the latest ATRS lower (and upper/barrel for that matter). Fully ambi, Canadian made.
My 9" barrelled ATRS .300 Blk shoots 10s at 300 meters all day.
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How well does it handle subsonic rounds? All my research shows me that the AAC is the most reliable. And I really like the look of it especially with the KAC handguard.
 
No issues. I have shot all sorts of SS ammo. really only accurately out to about 150 meters. I have perhaps shot about 7-8000 rds with only ammo related failures. In fact, we shot about 1400 rds without cleaning it and it still ran fine. I can PM pics of my 2 guns
 
Competitive, but I cant remember exactly. I have an AAC as well, but generally reach for the ATRS when I hit the range. Call ATRS and ask for Rick...Tell him you would like a build like Rod's and I am sure he will price it out for you.
BTW, this carbine was demoed to the Edmonton Police Tac team on the range a couple of years ago and they loved it.
 
I will contact them after shot show, but looking at website an AT15 in 300 BLK costs $3400 which is quite a bit more than the AAC upper for $1500 and a lower assembly of $1000. One could argue that ATRS will do a better job of putting it together but not sure if it will be a $900 diff.

Thank you for the info.
 
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This is my build.
Custom stainless 12 inch barrel
NEA upper and lower
Fail Zero nickel boron BCG
BCM Mod 4 charging handle
Daniel Defense buffer tube and castle nut
Troy Alpha forend with built in flip up sight
Magpul CTR, MOE+, RVG
Daniel Defense LPK
Standard carbine spring and buffer
Hi-Lux CMR-AK
Burris PEPR QD mount
S&J linear comp
Phase 5 EBR-2

Assembly by me :)


View attachment 20833
View attachment 20834
 
Rainer Arms billet lower has an ambi bolt release at a very reasonable price (around $360 IIRC). Other ambi controls like safety and mag release can be added to make it full ambi. I'm waiting for OST to get some more in stock.
 
Phhtt. Buy a bbl and put the thing together yourself. You could prob assemble an entire rifle for between $1000 and $1500 and you get the exact parts you want. Hell, if it keeps you from spending huge dollars I will volunteer to put the thing together for you ... gratis.

FWIW as a lefty I don't get the need for ambi controls on an AR. Never had problems manipulating the controls as they are.
 
Suputin said:
Phhtt. Buy a bbl and put the thing together yourself. You could prob assemble an entire rifle for between $1000 and $1500 and you get the exact parts you want. Hell, if it keeps you from spending huge dollars I will volunteer to put the thing together for you ... gratis.
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This ^^^

I forgot to mention that Suputin is also the one who built my barrel for me.
My build was well under $2000 and it has been 100% reliable and shoots some nice groups with ammo I had built for a different rifle, once I have time to do a little development with this rifle I'm sure it will be shooting sub MOA just like the other 300BLK barrel Suputin built for me.

Putting an AR together from parts is a great experience and isn't hard at all if you buy the right tools to do it. It's addictive though, I'm always looking for deals on parts so I can start putting another one together.
 
I originally wanted to build one, but was dissuaded after reading about how the 300 BLK is a finicky round and there are lots of rifles out there that have trouble shooting ammo etc etc.
And that building a 5.56 ar-15 is easy but 300 BLK is more of a challenge getting right. I want it to work the first time and not have to mess around with it. If you say that it can be done reliably and at a decent price then I am inclined to do so. I guess I need to start sourcing parts then.

Suputin, can you PM me, I am unable to message you.
 
Kanwar88 said:
I originally wanted to build one, but was dissuaded after reading about how the 300 BLK is a finicky round and there are lots of rifles out there that have trouble shooting ammo etc etc.
And that building a 5.56 ar-15 is easy but 300 BLK is more of a challenge getting right. I want it to work the first time and not have to mess around with it. If you say that it can be done reliably and at a decent price then I am inclined to do so. I guess I need to start sourcing parts then.

Suputin, can you PM me, I am unable to message you.
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My 300BLK work great, just don't get sucked into the 5.56 mentality of heavy buffers and full auto BCG's. The 300BLK doesn't need that stuff.
The only problem with 300BLK is that not all factory loads and not all reloading data work well in a semi auto, I have loads that work great in my bolt action that won't cycle a semi auto. Once you've been reloading it for a while you get a feel for which powder is best with which projectile weight in your rifle. I find that H110 is great for the lighter pills and A1680 works great with the heavier stuff. I also use Lil'gun as well with some of my mid weight loads.
 
Kanwar88 said:
I originally wanted to build one, but was dissuaded after reading about how the 300 BLK is a finicky round and there are lots of rifles out there that have trouble shooting ammo etc etc.
And that building a 5.56 ar-15 is easy but 300 BLK is more of a challenge getting right. I want it to work the first time and not have to mess around with it.
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Dunno where you read that but I have 4 300 BLKs and they all run reliably using the exact same ammo from the same set of dies. And I have bbls built with at least 3 different reamers and everything seems to work with everything else.


If you say that it can be done reliably and at a decent price then I am inclined to do so. I guess I need to start sourcing parts then.
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It can. 300 BLK is simply a different bbl. Everything else is exactly the same. If you want you can go with an adjustable gas block but it is reasonably easy to set a rifle up to run both subs & supers on a single gas setting. There are a bunch of threads on building your own AR and the tools required are not all that expensive.


Suputin, can you PM me, I am unable to message you.
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I can't cause the mods turned off my PM function .... because I am a bad boy apparently.
 
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