Suppressor load

[Stephen H]

if the powder is still burning after the bullet exits you can get inconsistent pressures and bullet speed due to the expanding volume of the suppressor. In short you want your powder to burn in the barrel not the suppressor. Plus I have some personal experience with 300 WM and 570 with a suppressor. as well as many other powders. So while the OP did not say that he was using 570 I was making an assumption that he was probably after Max speed as most people are. If the OP is in fact using 570 I could recommend several other powders that would likely work better. Use this data or disregard as you see fit.

 

[ChrisNZ]

I love shooting suppressed but no longer use them in competition, got tired of the inconsistancies that would crop up from time to time.... worst case was a 308 that would print a good group but location of group changed every time suppressor was installed. ..

If the can you're using is a reflex design with a bored rear bush, the problem here is almost certainly that the bush is touching the barrel when it's fully screwed on. Any touch is likely to produce variable zero each time it's refitted. Make sure you have true clearance all round.