300 Blackout AR Pistol - actually pretty accurate

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AJMD429
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300 Blackout AR Pistol - actually pretty accurate

Post by AJMD429 »

Finally got some range time with the nearly-budget-neutral 300 Blk Pistol project I made by cannibalizing an existing AR I had, selling some stuff off, and buying a pistol buffer tube and 300 Blk barrel from CMMG. The costliest item was the folding stock adapter from Law Tactical, but it is very well made, and would be useful on any style AR-15 or AR-10.

I had to use some factory ammo (still not sure what the two different Remington 220 grain loads are), but mounted a scope to see potential accuracy (at 50 yards), and then used that zero to sight in the laser. Now the next step will be to sight in the irons, which I intend to be the primary sights. The irons work when the gun is upright, but it is WAY faster to bring on-target at the 45-degree angle, and holds way more naturally that way, depending on how you choose to implement the Sig Arm Brace. Best use is with two hands at 45 degree angles from vertical; it is the only way I can hold the gun 'out there' steadily very long.

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Last edited by AJMD429 on Sat Jan 17, 2015 9:33 pm, edited 4 times in total.
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rjohns94
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by rjohns94 »

Awesome! My brother just picked up for me a lower and parts kit. My build is underway! Think I will be joining you with the 300 blackout. What barrel length did you go with? 10.5?

What folding mechanism did you use for the recoil system/ sig brace
Mike Johnson,

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AJMD429
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by AJMD429 »

I went with 8.5" because I will often attach my Mystic can to it. So far I've got the adjustment on the gas block to cycle everything from 125 grain supersonics with the suppressor (easiest) to 220 grain subsonics without the suppressor (hardest challenge, but works flawlessly).
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44magHunter
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by 44magHunter »

Move your light to the top-left. You will be most pleased by results! :mrgreen:
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rjohns94
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by rjohns94 »

It's a laser
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Griff
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by Griff »

AJMD429 wrote:...(still not sure what the two different Remington 220 grain loads are...
2 $s. :P :P :lol:
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The R300AAC8 is a Boat-tail and the L300AAC4 is a Flat Base. Currently their website only lists a L300AAC2 which is a 115gr closed tip at 2285fps... the 220 is shown @ 1015fps.
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firefuzz
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by firefuzz »

The top box, 220grn OTM is the old Sierra Match King 220 HP. The changed the name from HP to OTM for political reasons. It has no cannelure. Not sure about the other only that is has a visible cannelure.

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Paladin
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by Paladin »

Nice looking set up, well done.
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44magHunter
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by 44magHunter »

rjohns94 wrote:It's a laser
If that was in reference to my comment about moving his light... Actually he has a light AND a laser on there. The bigger, gray one is a light and the one up top is a (LaserMax ?) laser. I am saying he should move the light over because it will be easier, quicker and more consistent and far as hitting the on switch :wink: :mrgreen:
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rjohns94
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Re: 300 Blackout AR Pistol - actually pretty accurate

Post by rjohns94 »

My bad, thought the laser was BUIS. Sorry :oops: :(
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