Poor grouping with supressed AR10 308W

[Paqueo]

Have a Savage MSR 10 Hunter in 308Win.

Has a free floated 16” semi heavy fluted barrel 1 in 10” twist with an adjustable gas block.

Can group slightly under 1 moa with SMK190 @ 2510 fps using the original muzzle brake but can spread shots to 1’ with suppressors like this:

https://enn.aimsport.se/triton-no.-5.html

big and heavy or with this one:

Jaki Titanium Super with 11.6 ounces and a bit less than 8 inch long that add 5.5” to barrel length. https://www.jaki.fi/en/products



Already confirmed that barrel nut is torqued to 30 lbf/ft and also the adjustable gas block.

Same happened with a load with 130grain Barnes TTSX.



Anyone experienced something similar or has any explanation and solution for this?

 

[hlee]

1', like 1 foot group? Any indication of a baffle or end cap strike? Nice clean holes in the targets? Adding a suppressor can certainly change the barrel harmonics. And, the addition of a suppressor can negatively affect the function of a semi auto rifle. You may just need to find the load that the rifle+suppressor combination "likes..."

 

[Paqueo]

1', like 1 foot group? Any indication of a baffle or end cap strike? Nice clean holes in the targets? Adding a suppressor can certainly change the barrel harmonics. And, the addition of a suppressor can negatively affect the function of a semi auto rifle. You may just need to find the load that the rifle+suppressor combination "likes..."

Yes, can spread shots 1 foot apart @ 100 yards without baffle or end cap strikes and nice clean holes in the targets.

I adjust the gas block to just send to BCG the minimum amount of gas to cycle properly and developed a load with the suppressor on looking for best grouping and regular POI and velocity. After a few shots with the suppressor the gun start shooting weird shots.

Tried mild loads with other bullets. After a few shots with the suppressor starts shooting badly.

Also tried with a different scope and with a smaller and lighter suppressor not to cause major difference on barrel harmonics but after a few shots gets crazy as well as the owner

 

[UpSideDown]

Is the weight of your suppressor dipping the barrel down enough to have the barrel or gas block touch the handguard?

 

[acudaowner]

the shooter ?

using the force is tricky might be easier with your eyes open just saying .

 

[Maxduty]

Try the FGMM 168s. Mine wouldn't shoot 175s well with or without suppression. Stacks the 168s.

 

[Paqueo]

Is the weight of your suppressor dipping the barrel down enough to have the barrel or gas block touch the handguard?

No. Free floating

 

[Paqueo]

the shooter ?

using the force is tricky might be easier with your eyes open just saying .

??? Sorry I can't see the image

 

[Paqueo]

Try the FGMM 168s. Mine wouldn't shoot 175s well with or without suppression. Stacks the 168s.

Also thought on trying with some SMK168 but left the idea as same happened with 130 and 180 grain. Anyway might give it a try...

 

[hlee]

It sounds like you are saying that it starts by shooting fine with the suppressor, but then opens up as the barrel heats. Is this correct? If so, how many rounds? One foot groups are certainly excessive, but many barrels begin to string or otherwise lose precision as they heat.

 

[jetmd]

Is there any shims or a crush washer that was installed with the original muzzle device?
If so make sure to remove it/them prior to installing the can.
Do you have access to another suppressor you can temporarily install for testing?

 

[Paqueo]

It sounds like you are saying that it starts by shooting fine with the suppressor, but then opens up as the barrel heats. Is this correct? If so, how many rounds? One foot groups are certainly excessive, but many barrels begin to string or otherwise lose precision as they heat.

Yes but that only happens with the suppressor after 5 to 10 shots

 

[Paqueo]

Is there any shims or a crush washer that was installed with the original muzzle device?
If so make sure to remove it/them prior to installing the can.
Do you have access to another suppressor you can temporarily install for testing?

There is a shim/crush washer on the barrel but doesn't come out. What is your concern with the shim? Already tryed with a different suppressor but will try another one

 

[hlee]

If there is a crush washer between the barrel and the muzzle device, the muzzle device can be ever so slightly canted when timed. This can cause all sorts of accuracy issues with a suppressor that you will not see with a bare muzzle device.

It is best to bottom out the muzzle device on the thread shoulder, or use a shim designed for timing suppressor hosts, if they must be timed.

 

[Paqueo]

If there is a crush washer between the barrel and the muzzle device, the muzzle device can be ever so slightly canted when timed. This can cause all sorts of accuracy issues with a suppressor that you will not see with a bare muzzle device.

It is best to bottom out the muzzle device on the thread shoulder, or use a shim designed for timing suppressor hosts, if they must be timed.

OK. This suppressor do not need to be timed and I use it in other rifles without any issue

 

[jetmd]

hlee is correct.

That is where I was heading.

If a different can has the same results it will most likely be a barrel issue.