Suppressors Larger groups with can installed?

[BurnOut]

In another thread, I noticed some folks saying that their groups were opening up when they installed their cans. So here's my question: for those that experience this issue, are you using the same load for shooting your suppressed and unsuppressed groups?

What I'm getting at is that hanging a can off the end of the barrel will obviously affect barrel harmonics (as many have observed); so, with that in mind, how many of you who are experiencing larger suppressed groups (compared to your unsuppressed groups) are doing load development with your can in place? Theoretically (and logically), the ideal load with the barrel weight (can) installed could easily be different than the ideal load without it.

Thoughts?

 

[EasternNChunter]

Use heavier barrels if this is a concern but I have seen absolutely no difference with my brand new Thunderbeast 30BA on 2 different rifles shooting multiple loads.

 

[Buckeye308]

Most will have a point of impact change with a suppressor but accuracy should be the same if not better, I know my groups shrink when I shoot suppressed.

 

[3DHUSKER]

All suppressors are not built the same. I have seen several bad designs that degrade accuracy. There are also other factors that can cause this problem besides the suppressor.

 

[Icallem]

All suppressors are not built the same. I have seen several bad designs that degrade accuracy. There are also other factors that can cause this problem besides the suppressor.

This.

My AAC cans shoot for crap with their 51t mount, but with my Thunderbeast all is well. That said, I did have to back off the charge weight by ~2 tenths. This could have been due to timing, as I got the TB just as the temps were heating up outside.

 

[DeadNoise]

Ive got a Gemtech HVT 762 can, that has been on a 2 GAP's, 1 Surgeon and an AI and opens the groups up to 2in +. Its been sent back to Gemtech and they say there is nothing wrong with it and that its all within spec. Paper weight now. Sucks to wait that long to get something to ruins your groups.

 

[pkt1199]

If I run my non-suppressed load through the suppressor I end up with flattened primers and ejector marks. I had to back it down a grain or so to not see pressure signs. Not sure if this is typical or if I was right on the edge of pressure signs pre can.

TBAC 30p-1 on a Savage 308.

 

[Zak Smith]

The pressure max happens way before the main pressure is even applied to the suppressor.

It is most likely the case that some additional carbon accumulation is reducing clearance in the throat area.

 

[pkt1199]

The pressure max happens way before the main pressure is even applied to the suppressor.

It is most likely the case that some additional carbon accumulation is reducing clearance in the throat area.

Thanks for the reply! You are likely correct as I only shot suppressed that day with a known load but had not cleaned the rifle since its last outing shooting that load. Should have shot a few without the can to verify but who wants to do that.

Sorry to derail Burnout.

 

[Zak Smith]

The litmus test for that particular issue is if you clean the barrel including the throat area and starting shooting, the first few rounds will be fine and then within usually several the pressure will rise. We have seen this in just a few barrels and don't have a 100% answer but believe it has to do with a throat that is already tight and the additional carbon makes it just too close.

 

[Name Enough]

I had problems with my AAC SD6 can and it was caused by the can wobbling on the mount. MOA went from .75 to 3". I had the gunsmith grind the mounts so that the can locks up tight and now I get the same groups suppressed as unsuppressed. The POI will change with the additional weight on the barrel. Depending on the barrel length and weight. On my 12.5" barrel it is minimal but on an 18" barrel it can be as much as 1.5MOA depending on the load.

 

[nfoley]

Ive got a Gemtech HVT 762 can, that has been on a 2 GAP's, 1 Surgeon and an AI and opens the groups up to 2in +. Its been sent back to Gemtech and they say there is nothing wrong with it and that its all within spec. Paper weight now. Sucks to wait that long to get something to ruins your groups.

I have the same can. Had issues with it initially, sent it to Gemtech twice and both times everything was 'ok.'
I just kept using it and after some time (cannot recall how many rounds it took), it finally settled in. Now it has no effect on accuracy - my daughter just used it over July 4th weekend to win a 1000 yd shoot on a 6.5x47. I believe it was Lowlight that suggested to put more rounds through it.

 

[3DHUSKER]

I have the same can. Had issues with it initially, sent it to Gemtech twice and both times everything was 'ok.'
I just kept using it and after some time (cannot recall how many rounds it took), it finally settled in. Now it has no effect on accuracy - my daughter just used it over July 4th weekend to win a 1000 yd shoot on a 6.5x47. I believe it was Lowlight that suggested to put more rounds through it.

Like I said, bad designs........ There are cans that shoot perfect out of the box and don't need to be shot 500 times to settle it in. Good designs don't need to settle in.