Can a muzzle device change POI? ...by a lot?

[vicious_cb]

Vicious what's the logic behind this? Both AAC and BattleComp recommend 20-25 lbs on their muzzle devices.

Maybe if you are using it with a suppressor, the extra torque gives you extra insurance your muzzle device will not loosen with heavy can attached.

If you are NOT using a suppressor there is NO REASON to put any torque over hand tight with threadlocker. The logic is ANY added torque will "trumpet" the muzzle and affect accuracy.

[Eurodriver]

I am using a suppressor almost exclusively.

I know that a normal guy can torque about 15 ft lbs with his hands which would be totally sufficient unsuppressed.

That's the issue - enough torque not to come off with the can, but not enough to tweak the rifling or crown.

[vicious_cb]

I am using a suppressor almost exclusively.

I know that a normal guy can torque about 15 ft lbs with his hands which would be totally sufficient unsuppressed.

That's the issue - enough torque not to come off with the can, but not enough to tweak the rifling or crown.

So were you having accuracy issues with or without the can?

[Blak1508]

Maybe if you are using it with a suppressor, the extra torque gives you extra insurance your muzzle device will not loosen with heavy can attached.

If you are NOT using a suppressor there is NO REASON to put any torque over hand tight with threadlocker. The logic is ANY added torque will "trumpet" the muzzle and affect accuracy.

I always torque to 25-30 with all my MDs as per instruction recommendation and instructor recommendation. I have never had an accuracy or barrel problem doing so, on the other hand I have seen hand tightened to thread locked MD's come lose more than once during a course and in one case it blew through the spinning MD and could have caused a big shit storm. I like the "Logic" of torquing properly to value YMMV.

First I clean the thread on both the MD and barrel.
With a crush washer, I hand tighten and from there use a torque wrench and crank it to value and correctly timed. With peel washers I add them until I am hand tight at around the 11 mark and correctly offset timed, and from there torque to value and if done correctly at 12 I am just about or at 25-30 lbs of torque. I thought this was the correct way but maybe I am wrong.

[Eurodriver]

So were you having accuracy issues with or without the can?

Both.

[Blak1508]

You may want to check out the suppressor alignment tool from Geissele. Any strikes on your can ?

[vicious_cb]

I always torque to 25-30 with all my MDs as per instruction recommendation and instructor recommendation. I have never had an accuracy or barrel problem doing so, on the other hand I have seen hand tightened to thread locked MD's come lose more than once during a course and in one case it blew through the spinning MD and could have caused a big shit storm. I like the "Logic" of torquing properly to value YMMV.

First I clean the thread on both the MD and barrel.
With a crush washer, I hand tighten and from there use a torque wrench and crank it to value and correctly timed. With peel washers I add them until I am hand tight at around the 11 mark and correctly offset timed, and from there torque to value and if done correctly at 12 I am just about or at 25-30 lbs of torque. I thought this was the correct way but maybe I am wrong.

All of my muzzle devices are shimmed and tightened with rocksett and Ive never had one come loose. Note other thread lockers are not heat stable, this is why you use rocksett.

[Eurodriver]

How would the suppressor have anything to do with a 15 MOA change in POI when it isn't mounted? Definitely something with the mount. I can see a 6" shift. But to not be on a 24"x24" paper after a muzzle device swap seems really odd.

No baffle strikes.

[Blak1508]

What rail ? Lo-pro block ? If so what manufacture ? I may be reaching but I experienced something similar and I am wondering if it's close to the issue I had

[Eurodriver]

This is a factory BCM 11.5" LW Upper w/ 10" KMR that shot 100% to expectations out to 200 yards. 3MOA or so with a T1 at 200 yards right on target.

The only thing that was done to this rifle between it shooting fine at 200 and off paper at 100 (and about 5-6 MOA groups) was installing a BC 51.0 to ~30ft lbs. This was using the same ammo. I originally wondered if I might have used too much torque, thus distorting the crown/rifling at the muzzle, but after removing the muzzle device there was no way it was overtorqued.

The gas block isn't hitting the rail, I am not getting baffle strikes, I didn't use a crush washer, everything was done right. It's literally just the BC 51.0 on the end of the muzzle as a variable but I am really struggling to believe a muzzle device can change the POI by 15 MOA. Additionally, suppressed, my groups go from POA to 4 MOA at 8:00 which I've never seen this suppressor do on any other rifle (usually 2 MOA max, and always to 6:00)

It has since been re-installed to verified 25 ft lbs (well within AAC's 20-30ft lb spec). I'll try to take it back out this week and see if I can pinpoint what's really going on, but I wanted to ask here and see if anyone had any experience with an issue like this.