7mm STW problems...........need your input.

[Dave Hoback]

Yes, messy bedding is unsightly, but doesn’t always tell the tale to its effectiveness. A good way to tell if your bedding is a decent job: does the Barreled Action seem to fit like the stock is a glove? Does the stock “cradle” the Action? And when placed in the stock even without the screws, is it seemingly impossible to slide forward of backward any? Those are hallmarks of good Bedding.

Yeah, 1:9 is IMHO, the most versatile twist. For the typical length of a 160gr BTHP pill, the 1:9 is ideal. Your 1:10 may stabilize them “ok”, but yes, you likely will see better accuracy with the 140, or perhaps 150gr.

[8mm RUM]

I have an 8mm RM, it's the same case at the 7mmSTW, 375 H7H.
I run it HOT 220 gr Sierra 3100 fps, and 200 Barnes at 3200 fps.
It was a used gun when I got it, I have had it for 3 years and I my self have shot over 1000 shells.
There is no sign of a barrel problem. In fact I Just shot this 3 shot group at 100 yards.


​I'm betting you have a scope problem, I did not notice did you bed the action?

[Dave Hoback]

Yes, he was just talking about bedding, how it was messy. And we were just discussing it in the end of his thread.

[MtnOak]

I’m not saying the scope isn’t a small part of the problem but when your losing primers from factory rounds then there’s issues with the chamber of the barrel or action/bolt problems.
yes gun is fully bedded…

[Dave Hoback]

No, you DEFINITELY had something else going on. Popping out primers, case sticking in chamber.. those are OVERPRESSURE problems. And absolutely will affect the accuracy of the subsequent shots fired. That has nothing to do with the scope.

[Robinhood]

Pierced primers is not always a presure issue. Often it is a firing pin hole clearance and/or a firing pin tip profile issue. It does seem like preasure is the issue, but check the firing pin and hole for a place for the cup to flow.

Also primers being popped out requires enough clearance to allow that to happen. Over "sized" brass comes to mind. Check with a go and no go. Rent them if you dont have them.

Are you hand loading? If so what is your recipe?

Recheck headspace.

[Dave Hoback]

Pierced primers is not always a presure issue. Often it is a firing pin hole clearance and/or a firing pin tip profile issue. It does seem like preasure is the issue, but check the firing pin and hole for a place for the cup to flow.

Also primers being popped out requires enough clearance to allow that to happen. Over "sized" brass comes to mind. Check with a go and no go. Rent them if you dont have them.

Are you hand loading? If so what is your recipe?

Recheck headspace.

Oh, absolutely you’re correct Robin. I was aware of that. I’m confused as to the OP’s initial post as to if the the Primers were PIERCED, or BLOWN OUT of the primer pocket. The way I read it, the Primer was BLOWN out of the brass, which I believe is pressure related. A PIERCED Primer is due to something with the firing pin/striker, just as you mentioned.

And there is the sticking case he had. DEFINITELY pressure related IMO. But could have been a one off bit of random weirdness I guess. Hopefully he gets to shoot shoot & lets us know if the work made a difference.