7mm RM and H 1000

[dwm]

red dawg, how close do you monitor your headspace? If your headspace goes beyond 2 or 3 thousands you may be seeing signs of pressure from excessive headspace, instead of from a high powder charge. This happened to me with a 6.5-300WSM. I had a great H1000 load that all of a sudden started showing higher than normal pressure, ejector marks/sticky bolt, etc. It turned out to be too much headspace due to work hardened brass. One batch of full length sized cases headspaced correctly and another batch of cases full length sized short because the brass was too hard. Needless to say the bolt would bind up when I fired the second batch. I finally traced it to excessive headspace, not a high powder charge.

Something to consider ...

 

[red dawg]

My bolt is not tight but did have cratered primers. I had the barrel installed by a reputable gun smith. I will have it checked again! thanks for bringing this to mind

 

[dwm]

Oh I was talking about having the full length sizer die set too far down thus making your resized brass too short in the shoulder ...

So the primers are getting pretty flat?

Will a fired case fit back in the chamber?

 

[bruce_ventura]

Just to clarify, I'm not a proponent of running hot loads because it shortens brass and barrel life.

That said, I'm not convinced you're near max load either. The muzzle velocity is high, but not for a 27.5" barrel. I think you should re-check your balance and chronograph data. If you have a calibration weight, check your balance. Try a different chrono.

You've mentioned primer cratering a couple of times. That's not one of the pressure signs I typically look for. It happens at low pressure with some rifles and not others. Flattening of the primer is a better indicator to me, along with tool marks on the base and sticky bolt lift. If I really want to know, I measure the base diameter on a new case with a micrometer before and after firing. When the base deforms after firing, the load is too hot.

There are aren't a lot of reasons why you could be seeing pressure signs at such a low charge weight. No bullet jump and/or undersized barrel bore could do it. dwm also mentioned headspace. It could be a combination of effects.

 

[red dawg]

Yes cases will bolt with ease after fired and re checked in gun and I only neck size. I seat the bullet .005 to.010 off. I usually get 3 to 4 firings before I bump shoulder back on brass.