Suppressors Suppressor cover and prcision

[hlee]

Can a suppressor cover that shifts around during a string of fire cause issues with precision on an otherwise very precise rifle?

I shot a match yesterday and had a suppressor on my rifle. This was the first time shooting this combination in a match. Furthermore, this was the first time shooting the suppressor with a cover. Previously, I had experienced no change in the precision of the gun either with or without the suppressor, shooting prone or bench on a square range. Yes, the POI changes, but the group size does not- at least with the naked suppressor. But, I had not shot extensively with the cover. The cover, while tight, would shift forward by about 1/4- 3/8" over the course of a 10 round stage. The cover does have a cord that cinches it down on the can, and wraps around the rear to prevent slippage. However, it seems that the cord lock allows enough slippage that it all loosens up just a bit. The first round of the stage seemed to go where it was supposed to, but fell apart after that.

I'm not competing for first place finishes, but my score was ~1/3 of "normal," so I think there's more than my own rust at play.

After the match I went back to the zero range to see what was up. I had adjusted the cover so that it was not overhanging the end of the can, but had not noticed the cord was a bit loose. The first few shots, I couldn't find in the field of other impacts on the used zero target. With 5 rounds left I found a big clear spot on a target and sent a round. The impact was easily 1/2 mil off the poa. The second shot was further away. Shots 3-5 made a tight little group at the poa. I was out of rounds so packed it in. When I got home I noticed that the cover had again shifted ~3/8" forward- taking all of the slack out of the cord. Now I'm wondering, can a shifting cover kill your precision?

 

[Lunchbox27]

I have had my cover come loose many times. Almost to the point of sending it down range. I didn’t notice any difference. Honestly, I think you have something else causing this.

Only way to know for sure is to go back and shoot with the cover off. If everything is solid as before, throw the cover on loose and see if it changes your poi. Not saying it’s not possible, but a first I have heard of it.

Interested in your results. What cover is it?

 

[hafejd30]

Never seen my cover make a difference but it doesn’t slide forward either.

Only things I think that would contribute to that would be heat, gasses, barrel tuning or mirage....I think.

Tuning in to see what others say

 

[Precision Underground]

I’ve never seen a cover change accuracy. POI may change on a thin barrel but not a change in groups. Not sure I’ve had one sliding forward though. I would think the bullet would be long gone before any turbulence from the cover could affect it but I guess it’s possible. With our cord a key is to make the cord go 90deg down behind the can and then wrap back up. That takes any pressure off the cord lock and will make sure there is no slippage.

 

[hlee]

Well, more testing is obviously in order.

The rifle is a 6.5 Grendel "Franken-15" built on an Anderson receiver set. JP barrel, Geisele trigger. The can is a thunder chicken. The cover is a Rifle's only HAD.

I just looked at my reloading book and all of the test loads from my load work up were moa or better at 200 yards- 5 charge weights, 5 shots per weight. Of course, this was with a different brake, and no suppressor. I'll update the thread after some more shooting. I hope to get out this week, but we'll see.