Over-torqued flash hiders and accuracy?

[Circle_10]

So years ago when I first got the midlength upper that's been the subject of like two previous threads now, I didn't really know about torque values and just cranked a YHM Phantom flash hider on to the muzzle (using an M7 bayonet inserted through the slots....ugh..)
I'm pretty sure it's way over torqued.
Fast forward several years and I have heard that over torquing a muzzle device can be detrimental to accuracy by, IIRC, something to the effect of deforming the shoulder and causing the device to sit unevenly etc.. etc..

I have given some thought to changing out the Phantom for something else (I'd be adhering to recommended torque values this time...) But I'm wondering if I've already potentially dicked my barrel up by over torquing the Phantom.
The gun has a mid length 16" government profile non-free floated barrel with a standard A2 FSB. Currently, with optics (Both a Primary Arms 2.5x originally and now a Steiner P4xi 1-4x) I can get the gun to group between 1"-1.5" at 100yds with decent ammo (Hornady VMax, IMI 77gr.... sometimes even Prvi M193) as long as I don't get stupid and blow my shots, unsurprisingly I can do this more consistently with the Steiner than I could with the Primary Arms. As my other ARs are all iron-sighted and/or equipped with Aimpoints, I don't have any other ARs with magnified optics to compare to. Is 1-1.5 MOA about what a non free floated 16" AR *should* be capable of with optics or could I *potentially* improve that by having a correctly torqued muzzle device on there? Or, conversely, could I make it worse by messing with it now and I should just leave well enough alone?

EDIT: here's a recent target with the last batch of groups I shot with some IMI 77gr. Obviously as you can see by the black pasties covering some previous groups *I'm* a variable in this equation too but these are fairly representative of the groups I've been getting with this gun lately

[hotrodder636]

Interested to hear opinions on this.

[Circle_10]

In case anyone is wondering why my elevation is kinda inconsistent in some of the groups that's also me. The P4xi is supposed to be sighted in at 200 yds, not having access to a 200 yard range at the moment I sighted in at 50yds and so in order to actually hit inside the bullseyes at 100yds I have to hold a bit lower than desired POI. Sometimes I don't hold low enough and sometimes I hold too low.

[AKDoug]

Those are some pretty good groups with a non-free float barrel.

I've only messed with this with a 16" PSA blem midlength barrel that I got for $100. I went from 5 ftlbs to 50 ft lbs in 5# increments on an A2 flashhider and a crush washer. Shooting a 5 round group at each stop. It was a 2.5 moa barrel when I started and a 2.5 moa barrel when I ended. I was looking for a drastic change in group size and never saw it.

Is that going to be the case with every barrel and every flash hider? I don't know.

I do know that if I have to go to 25# to get an A2 to index I really don't worry about it anymore.

[sinister]

Over-torquing a muzzle device causes the barrel to stretch and "Bugle." Bullets traversing down the tube suddenly hit the flared end and you get inconsistent gas blow-by around the boat-tail or base of your bullets. Precision crowning of the barrel becomes a moot point.

USAMU gunsmiths use shims and just lightly tighten A2/A4 flash suppressors. Other gunsmiths time the barrel shoulder and use red lock-tite to keep the flash-hider from unthreading or backing off.

The bayonet and retard strength tighten-torquing method is not helping your case for precision, even with precision handloads, a good free-floated barrel, a good trigger, solid rests, no wind, and awesome shooting technique.

[Ned Christiansen]

Over torquing will collapse the bore under the treads. I saw one that gage-pinned .004 under; it had been shot quite a bit in the condition so was already in the process of being shot back to a .224 groove diameter. Needless to say accuracy sucked and continued to suck after the device was taken off (threads had been stripped).

I often done even go beyond hand-tight. Have not used the tq wrench on a muzzle device in quite a while but I'm sure I never even get close to the bottom end of the range.

[Circle_10]

Yeah, I won't be doing the bayonet thing again. Chalk that up to ignorance. I have both an awareness of proper torque values and the tools to actually achieve them now. But I still have some lingering mistakes from the "old days"...

So in my case is it worth changing the muzzle device out and making sure the new one is torqued to a much lesser degree, or are the groups I'm getting about as good as I'd probably get from a non-floated 16" midlength anyway? I basically just wanted a flash hider that was a bit less err.. "kludgy" than the phantom, but if messing with it is unlikely to add any benefit, or might perhaps even be detrimental at this point perhaps I should just leave it alone.