ACR Media and Info Thread
- Thread starter McFlurri
- Start date
Just got mine back from black box. Had the upper and lower cerakoted magpul OD green. Waiting for a long RPM handguard. Had the NR conversion done by Herron and barrel cerakoted black, and I put a super acr trigger in.
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Thank you !
This is so wrong...
Idealizing barrel twist rate to the bullet weight/length is the most basic and fundamental key to accuracy.
Running light bullets from a fast twist is better than running heavy/long bullets through a slow twist, but that general truism is about as far as I would agree.
A bolt gun with a 1:7 could be ran with light bullets with good accuracy if the velocity is dialed down to compensate for the over rotation, but the ACR is a semi auto and pressures with such a load may not cycle the rifle. If you run light bullets at high velocities in a 1:7 you can get a number of problems caused by centrifugal forces which can cause the bullet to fly apart in flight or almost fly apart in flight. This does not help accuracy.. especially when you see little pepper flake holes randomly appear on the target when the bullet flies apart.
I tested this stuff in great detail back in the 1980s when my standard hunting rifle was a Colt AR15 A2 Delta Hbar which was not restricted at the time.
I always liked the 1:7 for that rotational energy and how that rotational energy affects how the bullet performs on impact particularly with 69 grain SMKs. On the other hand, the opposite is true with green tips or FMJs.
The 69 grain SMK fired from a 1:7 hits a ground hog like a 308, but most FMJs and armor piecing type ammunition from a 1:7 will poke a clean hole and leave the animal wounded. Without fragmentation or expansion some bullets perform badly on impact.
I know some guys like running cheap 55 grain ammo with 1:7 and yes you can do it, but do it knowing accuracy is going to be sacrificed accordingly. Going even lighter gives up even more. To me that's like golfing and using a putter for your first tee shot... you can do it, but its just not right.
The real advantage of the 223 with 1:7 is about terminal performance and you will get best terminal performance running a full load with a bullet that is designed to just barely tolerate the rotation. Just under the ragged edge of destruction is where the juice is where the bullet explode violently on impact and causes the most damage.
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I agree with a lot of what you said but I've done accuracy testing (not terminal performance) and been able to get good groups from barrels with twist from a 1:7 to a 1:12 and gotten good groups at shorter distances with almost any projectile, as long as like you say you pick an appropriate bullet for the velocity and spin it will experience. I've had bullets come apart as soon as they left the barrel of a 20 in 7 twist AR but with a bullet designed for it like a Varmint Grenade it holds together and comes apart nicely on impact.
All I'm saying is that inside 300 meters when it comes to accuracy the bullet weight doesn't mean much as long as the barrel finds a nice harmonic with the load. You also see little to no benefit from a boat tail within 300 meters, but once it gets past that distance you can see the increased BC maintaining velocity better in the drops. Terminal performance is a different discussion and I agree, spin it as fast as you can without it coming apart for better fragmentation. I've never experienced over spinning a bullet negatively affecting accuracy though, only that funny sound when the bullet comes apart as it clears the muzzle.
Big ACR life question.
I have a regular ACR and another newer DMR version I was building.
Should I keep the DMR build and turn the 2nd ACR into a restricted 10.5" gun?
Or
Sell the DMR build and buy a 7.62x39 conversion kit for the standard ACR to take advantage of the multicaliber properties?
Cons I see for both
Restricted ACRs are harder to sell
I don't shoot restricted rifles very much (and have a Colt IUR)
I already have a XCR M DMR set up
I have a regular ACR and another newer DMR version I was building.
Should I keep the DMR build and turn the 2nd ACR into a restricted 10.5" gun?
Or
Sell the DMR build and buy a 7.62x39 conversion kit for the standard ACR to take advantage of the multicaliber properties?
Cons I see for both
Restricted ACRs are harder to sell
I don't shoot restricted rifles very much (and have a Colt IUR)
I already have a XCR M DMR set up
polskadude
CGN frequent flyer
- Location
- London Ontario
I'd be surprised if the XCR can match the ACR's accuracy provided the ACR barrel is tightened properly. The barrel on the ACR DMR is really nice, and it runs a MUCH nicer trigger as stock being a G.
On topic, anyone see the new KRG ACR stuff? two stocks, one PRS style for 400, the precision one that folds for a lot more. But their new rail looks amazing.
A 10.5" with that PRS stock would be awesome.
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I don't think thats an ACR. ?
