The Bushmaster guy says that the melonite coating and the piston system makes it so that the ACR should be run WITH OUT ANY LUBE. He said the lube will just attract crap and cause issues.
Not saying it ain’t so, but just seemed a bit optomistic. Anyone have a manual for an ACR, what does it say?
Also says that they 1x9 barrels have been shown to stabilize up to 77gr bullets.
the owner shoot 69gr and 75gr out of his 1:9 barrel at 100 and 300 yards, seems fine to me? Also does a return to zero test (gotta mark the barrel and trunion so you ratchet it back in the same spot) and it does RTZ. This guy is from East Texas I believe.
I squeezed in about 45 minutes of trigger time before dark.
I wanted to look at how some commercially available longer, heavier .223 bulllets performed. There’s always been a lot of talk about how the 1 in 9" twist barrel can’t accurately shoot the longer bullets.
First I shot two ten shot groups at 100 yards using PRVI Partisan 75 gr and PRVI Partisan 69 gr. Both are labeled by the manufacturer as Match ammo.
The PRVI 75 gr group at 100 yds…
( a little over 1.25")
The PRVI 69 gr group at 100 yds…
( a little over 1.4" …well, if you don’t count the low ball ) That was a poorly shot group by me.
Now at 300 yards…
I placed the bullseye targets over a CSAT silhouette. The POA was the green/orange center which matched up with where the neck comes into the shoulder. Shooting downhill with a drop of about 9-10’.
I have zero info on the PRVI ammo. I have no idea of the ballistics. I do not see it in their catalog or on their website.
I fired 9 shots at the center of the target and one holding at 12 o’clock in case I did not hit the bullseye.
PRVI 69gr at 300 yards…
The group averaged about 8.5"-9" low. The shot aimed higher was 8.5" low.
The horizontal spread was 2.5" and the vertical spread of the lower group was 3.5".
I was down to my last 5 rounds of PRVI 75gr… at 300 yards…
I clearly pulled one right. I knew it as soon as I pulled the trigger.
Not counting the flyer, that group was measured 2.25" horizontally and 2.75" vertically.
The rough center of the group was about 6.5" below the center POA.
The bullseye over the silhouette…
and under the bullseye, the silhouette…
from a tactical, self defense standpoint , that works for me with the PPU long bullets. Granted I have seen BUIS shot targets at 300 yards better than that. But at least the 1 in 9" twist barrel can get it done with these longer bullets up to 300 yards . Please note, I do not presume that ammo such as Brown Tip or Mk262 would give anywhere near the same results. They are a different breed of cat.
I have to do some serious mowing before I can push back to 400 yards and see what happens there.
I hope to post some pics of the gas piston assembly and its operation in the next few days.
I’ll get to it as quick as I can but I have a LaRue OBR arriving tomorrow.
BTW, the easiest way to get the barrel locking ring tightened that last little bit is by using a small length of tubing or a pipe as a cheater bar. It just snugs right up tight.
I plan to talk to some tech reps at Remington on Friday to see if I’m missing anything.
Hopefully I’ll have a Tan ACR by the time the HGCA show rolls around next month.
J
I have a little north of 2k rounds shot out of my acr in various training drills.
When I first pulled it out of the box I shot about 300 rds then dumped it into muddy watter fired 600 rounds , then dumped in mudd soup and it worked without a problem.
This rifle has yet to be cleaned or lubed
When you tear it down to clean, could you post some pics of the bolt, carrier and other wear items?
Bushmaster does a rather pathetic job of sales on the rifle. If it really this wunder coating, get out there with some pics of groups with the coated barrels and the rifles parts that show the lack of wear.
Lubrication does more than just make shit slippery.
Lubrication cleans foreign matter between moving surfaces, cools, cushions and preserves.
“Wondercoatings” do only two of those things.
If it’s a machine, it needs lube to function ideally.
I challenge the assertion that foreign material is attracted/trapped by lube between two clearanced parts. The swiping action of those parts ensures the lube lifts that same matter and allows it to be carried away.
I also challenge the assertion that maintaining proper lube is such an onerous task that you need a new weapon systems so you do not have to do it.
Oddly enough, Walter, the Czech engine manufacturing company, made a “lubeless” engine during the 1930s. All the bearings were sealed wet bearings and cooling was by forced air. They were horrifically expensive to purchase and maintain. But they worked.
) That was a poorly shot group by me.
