I was running a 155 scenar with varget 46.5 grains to be exact. This load was safe in my rifle. I tried it suppressed and noticed shiny spots/ swipes on the case head? The other factor was a new can of Varget. Thanks

Gotcha, I'll be reworking up the load.

By the time the bullet and the hot gases reach the suppressor, chamber pressure is way below peak pressure.

I have found that suppressors sometimes/often cause pressure signs in cases, but every time I pulled the suppressor off and shot the same loads over a chrono, there was no difference in velocity suppressed vs. unsuppressed.

Is this a bolt action or a gas operated semi auto? Chamber pressure isn't affected, but a gas operated semi auto can cycle differently with a can.

Varget can easily vary by .5 grains or more lot to lot in a .308 with 155s.

Thanks guys. It was a bolt action. Brass was easy to eject but observed the pressure sign on case head.

Pull the can and check the load without it. And check it over a chronograph if you want to be sure.

Good info

Lots of guessing in this thread.

Without doubt a suppressor can add to time under the curve and show swipes and brass flow with loads that don't unsuppressed.

Area under the pressure curve in a gas system of a semiautomatic sure, adding a suppressor can cause timing issues.

But a can will not cause brass issues in a bolt action in an otherwise normal pressure load. Peak chamber pressure is within the first few inches of bullet movement, by the time you get to the end of the barrel, residual chamber pressure is way down and drops off when the bullet exits the muzzle, just not as much as If there weren't a can. Having a few extra inches of barrel would cause much more area under the tail of the pressure curve there. The suppressor is not the issue, the new can of Varget is.

Yup.

Thanks guys. Its an education and lesson.