Thread: Point of impact change

Forgive me if this been dealt with previously.
Recently purchased a Tikka 308 with DPT suppressor. Worked up a load with 168gr Amax. Most impressed, first group 13mm, second 20mm so happy.
Just out of interest tried it without the suppressor. Group expanded to around 40mm and POI dropped around 60mm.
My question is, is this normal?
Cheers

POI being different is normal however it should still group the same. It could be the big bang or extra recoil affecting your shot

Originally Posted by tibo

POI being different is normal however it should still group the same. It could be the big bang or extra recoil affecting your shot

Agree with POI being different is normal.

I don't agree that it should group the same, taking the suppressor off is a big change of weight hanging off the end of the barrel. It will shoot with different accuracy (good or bad). Typically people report a slight reduction in group sizes with suppressors for what ever reason. Possibly related to your final sentence.

I do agree shooters probably shoot better with suppressors because of the significantly reduced noise and perceived recoil reductions.

weird your POI dropped without it...normally its otehr way around if change at all....for spook n shoot under hundy yards and chest shots,none of my rifles change enough to blame a miss on...but to be honest I VERY VERY seldom shoot without one now.

Originally Posted by Makros

Agree with POI being different is normal.

I don't agree that it should group the same, taking the suppressor off is a big change of weight hanging off the end of the barrel. It will shoot with different accuracy (good or bad). Typically people report a slight reduction in group sizes with suppressors for what ever reason. Possibly related to your final sentence.

I do agree shooters probably shoot better with suppressors because of the significantly reduced noise and perceived recoil reductions.

What I meant is if a rifle group with a can then it can group without, it isn’t hardware related.

Supressor off vs on can certainly change not just POI but group size too. On one of my rifles, I developed a load with a hardy magnum supressor on it, got it shooting .3 moa. When i put my muzzle brake on instead, POI shifts but group size stays basically the same. However just bought an ATEC H2 Supressor for it recently, same load now shoots just over an inch group with the ATEC on. Put the hardy back on, back to normal again. Going to have to do another seating depth ladder if i decide to keep the ATEC supressor on it. Any time you attach anything to the barrel it changes the barrels harmonics, sometimes for better, sometimes for worse.

Originally Posted by 6.5 CRD

Supressor off vs on can certainly change not just POI but group size too. On one of my rifles, I developed a load with a hardy magnum supressor on it, got it shooting .3 moa. When i put my muzzle brake on instead, POI shifts but group size stays basically the same. However just bought an ATEC H2 Supressor for it recently, same load now shoots just over an inch group with the ATEC on. Put the hardy back on, back to normal again. Going to have to do another seating depth ladder if i decide to keep the ATEC supressor on it. Any time you attach anything to the barrel it changes the barrels harmonics, sometimes for better, sometimes for worse.

Interesting, never noticed difference between my DPT and the H2, learnt something today thanks.

Originally Posted by 6.5 CRD

Supressor off vs on can certainly change not just POI but group size too. On one of my rifles, I developed a load with a hardy magnum supressor on it, got it shooting .3 moa. When i put my muzzle brake on instead, POI shifts but group size stays basically the same. However just bought an ATEC H2 Supressor for it recently, same load now shoots just over an inch group with the ATEC on. Put the hardy back on, back to normal again. Going to have to do another seating depth ladder if i decide to keep the ATEC supressor on it. Any time you attach anything to the barrel it changes the barrels harmonics, sometimes for better, sometimes for worse.

What caliber were you shorting out of curiosity?

yeah bro normal as

Originally Posted by tibo

What caliber were you shorting out of curiosity?

Tikka 300wsm. However my Tikka 6.5 PRC shot the same group size with no supressor, atec, and h2, just different points of impact. Go figure

A suppressor changes the barrel harmonics which can have a significant effect in point if impact and group size. The effect of weight changes on the barrel is well known, so called barrel tuners used to be made that you could adjust to in theory to find the nodes.

Thanks for the feedback. Some varied opinions out there.
Recoil wasnt a problem without suppressor so dont think it was a "shooter" related problem.
Conclusion would seem to be dont remove the suppressor.

Forgot my suppressor few weeks ago, Oceania with ratchet lock. Shot off the brake that suppressor locks onto, group moved up and left 1.5 inches approx. This is fairly consistent with what I've seen in the past on other rifles, group size seemed unaffected, very good.

So suspect POI pretty much will always move but group size may or may not depending on rifle/suppressor setups and their various characteristics would be my guess?

Suppressor on or off changes the barrel harmonics, it’s normal for a poi change, I’d imagine changing harmonics could also have a noticeable effect on grouping

If you are believer in optimal barrel time, I'm pretty sure the guy who came up with that theory tested and that didn't change with muzzle brake or suppressor, which surprised me.

I'd take each rifle on an individual basis on this one around grouping. Imagine pencil barrel/ heavy suppressor vs heavy shorter barrel/ titanium suppressor would yield different results?