Suppressors  speed increase normal?

dukedurham

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I recently cut and threaded the barrel on my Salvage varmint rifle to use my Shark. Went from 24" to just a RCH over 20" and when rezeroing found that the POI had risen considerably. By all accounts, losing a bit of barrel and the addition of the can I would have thought to be a wash. You guys wanna weigh in?
 

HoustonPdLt

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Re: speed increase normal?

Maybe a RCH was to much? Should have tried a BCH first? BTW! That's my favorite form of measurement too.
 

Outsydlooknin75

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Re: speed increase normal?

You know that a red is thinner than a black but thicker than a blonde ... red is kinda middle ground
 

HPLLC

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Re: speed increase normal?

Are you talking about an unsuppressed 20" to suppressed 20" zero shift, or a change in your point of impact from when you had the rifle cut and threaded to now with the suppressor?

Dissassembling the rifle could alter the zero somewhat.

Outside of that a POI shift from unsuppressed to suppressed (UP) would typically mean that the can has a slightly up attitude on the end of the barrel. Bullets will tend to follow the bore of the can, and adding a can with perfect alignment should generally result in near zero- or low POI shift from adding the weight to the barrel.
 

Rlb40x

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Re: speed increase normal?

It probley has to do with the harmonics, I have seen this with a friends 25/06. His faster loads printed lower on paper than his slower rds because of barrel whip, with his faster rds his bullets were exiting the muzzle in the low cycle of his barrel, it was pointed down so the rds printed lower, hope this makes since,Bob.
 

HPLLC

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Re: speed increase normal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rlb40x</div><div class="ubbcode-body">It probley has to do with the harmonics, I have seen this with a friends 25/06. His faster loads printed lower on paper than his slower rds because of barrel whip, with his faster rds his bullets were exiting the muzzle in the low cycle of his barrel, it was pointed down so the rds printed lower, hope this makes since,Bob. </div></div>

It's definitely possible, but the Savage Varmint guns do have heavy barrels which should limit barrel whip somewhat. Typically the suppressor would also dampen barrel whip, but in this case it could be the dampening of barrel whip that causes the POI shift.

How heavy was the barrel on your friend's 25/06?

The only experience I have with barrel whip was with the 10.5" SCAR-L. Without the can the gas tappet operating system seemed to cause wild group dispersion (7.5MOA) compared to ~3MOA with the suppressor on. So I wasn't sure, but figured that the weight of the suppressor dampened the barrel whip.
 

Rlb40x

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Re: speed increase normal?

My friends 25/06 was a small barrel, but I have seen it with bigger ones. I shoot a lot of sanctioned rimfire benchrest and we all use tuners on our muzzels, I use a lilja .875 dia and my tuner is 8oz and moves in and out in 1 thousands increments and if I go 20 to 30 it with change my poi as much as 1/2 to 3/4" and these rifles group in the high zeros to low 1s at 50 yds, so it dosent take much to change poi. I also have a 308 that shoots 1/2 to 5/8 with my lite weight Barrett brake, then I put my YHM qd brake on it and it shot terrible 1.5 to 2" with it so I may have to retune my load, don't know yet haven't shoot my suppressor it's still at the dealer but I hope it will calm it down when I put it on,, I was happy with my groups for a factory barrel, may have to change my load, well see this fall,Bob.
 

dukedurham

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Re: speed increase normal?

Maybe all the tear down and put back changed the zero, don't know. I guess i'll just have to take my friend's crono out and test to see. Either way, i'm stoked as hell that i finally got to shoot the thing w/the can. Looks like its gunna shoot just fine with a few adjustmests for zero; don't think the groundhogs will ever know the difference. Thx