Supressors - Temperature vs grouping?

Hi guys. Question for the more experienced shooters than i regarding supressors. Interested to know what others have experienced in regards to how their gun groups as the supressor gets higher in temperature from multiple shots. I currently run a 6.5 creedmor for my general hunting, has a dpt magnum on it and at the range i can do 2x 3 shot groups before the supressor starts to get too hot to touch & i notice it start to not group as well (not drastically). Let it cool for 10 mins and carry on and its back to normal. Recently purchased a tikka in 300 win mag which came with a hardy stealth fitted, for the size calibre its surprisingly both soft to shoot & very quiet for a 300 win mag.(noticeably better than my 7mm rem mag with a gunworks maximus). However, by the 3rd shot its getting too hot to touch and the grouping opens up fairly drastically (100m, first 2 shots touching each other, 3rd leaves the first 2 by an inch or so, 4th sometimes as bad as inch and a half. Let it cool down for a couple mins between shot 2 and 3 and its not a problem, will group with all 3 holes touching each other or near to. I do realise in the real world hunting this is unlikely to be an issue as for what im doing the need for 3x back to back shots is slim to none, just interested to see what others opinions are, is this something directly related to how “restrictive” the supressor is ie doing its job, would a less “restrictive” supressor allow for more shots in succession before getting too hot, at the sacrifice of being louder and having more recoil? Interested to hear peoples take on it.

Cheers

Are you sure it's not got more to do with the barrel heating up rather than the suppressor? An overbarrel will insulate the end of the barrel and keep it hotter for longer as well.

Yes, i would assume that is whats happening, however im no expert so just looking for others inputs/experiences. I know my 6.5 doesnt have problems grouping wise if i run it without the supressor.

when you have fired 2 or 3 shots,whip can off to allow barrel to cool down quicker....
it also allows the damp air to bugger off elsewhere.
they sure do get hot..but not often I fire a long string of shots and when I do its into wallabies so dont notice accuracy....

Some rifles are quite ok with the heat, usually the heavier barrels. My hunting rifle is a M700 .308 with a slimmed factory barrel and it's a bit sensitive - groups stay the same size but they drop down and right...

The group sizes you are getting are still good enough for pest control accuracy. I have shot my suppressor dot with SS baffle so hot rain sizzles off it on a few occasions.

It's not mirage, is it?

The larger area or the can seems to make mirage worse - maybe it is affecting your sight picture.

Quite possibly yes, im not sure on the exact cause, hence the post. Was just explaining my symptoms in the hope that someone whos experienced this before pipes up and says "i had the same issue and i did x to resolve it". after the second shot, the supressor is quite hot already, and taking the 3rd shot you can notice the image through the scope is definitely not as clear compared to the previous shots, so would make sense in regards to the mirage theory, can certainly see the heat coming off it.

have you done the same without the suppressor to see what the rifle itself does without suppressor attached?

yes, sorry should have put that in the original post. with the supressor off, it will do 2x 3 shot groups fine with the second group only slightly worse than the first, likely my shooting causing that, kicks like a mule without the supressor on. so i feel i have narrowed it down to something directly related to the supressor and the temperature that it / the end of the barrel is getting to in a very short time frame (to me, 2 shots seems to be damn fast for a supressor/rifle to get to a temperature where its losing its accuracy. i understand its a relatively large calibre to be supressing, however my train of thought is, would fitting a supressor thats less effective at softening felt recoil/muffling the sound, potentially not build up so much heat so fast, & therefore take more shots to get to a temp that starts to hinder accuracy.

If its the suppressor just remove it. To help with recoil put some lead shot or sand inside the stock assuming it's a hollow plastic stock.

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Originally Posted by 6.5 CRD

yes, sorry should have put that in the original post. with the supressor off, it will do 2x 3 shot groups fine with the second group only slightly worse than the first, likely my shooting causing that, kicks like a mule without the supressor on. so i feel i have narrowed it down to something directly related to the supressor and the temperature that it / the end of the barrel is getting to in a very short time frame (to me, 2 shots seems to be damn fast for a supressor/rifle to get to a temperature where its losing its accuracy. i understand its a relatively large calibre to be supressing, however my train of thought is, would fitting a supressor thats less effective at softening felt recoil/muffling the sound, potentially not build up so much heat so fast, & therefore take more shots to get to a temp that starts to hinder accuracy.

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Could well be a can fitment issue. There should be clearance with overbarrels at the rear of the can between the barrel and the rear bush. If there isn't sufficient clearance the barrel can touch and stuff the works up.

I'd try a mirage shield to see if that is the issue. It can be as simple as a piece of cardboard 65mm wide, starting under the front bell of the scope and extending to the end of the suppressor. Masking tape will be fine to hold it on, and it won't affect the groups.

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Originally Posted by No.3

Could well be a can fitment issue. There should be clearance with overbarrels at the rear of the can between the barrel and the rear bush. If there isn't sufficient clearance the barrel can touch and stuff the works up.

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This ^

The rear bush is probably the issue. Take it off the suppressor and shoot some test groups.
I have experienced the rear bush issues with two rifles/suppressors now.
I think that the Bush either needs to be tight or quite clear of the barrel so that you don't get partial contact which increases with temperature.

Following up on this, @No.3 & @Roarless20 were on the money. rear bush was machined slightly offcentre & had next to no clearance on one side when barrel was cold. had a friend machine it properly to the spec hardy reccomend, problem solved. Cheers!

:thumbsup:

Awesome!
Glad you sorted it!