6.5-284 Norma Brass

[deanm]

I just got a new Cooper 6.5-284 and broke the barrel in this weekend. I loaded 142 gr Sierra's W/47.0 gr H4350, Fed. 210M.

I was getting a significant burr on the brass in the ejection button area, but the bolt lift and primers did not show excessive pressure.

Is this Norma brass extremely soft, or is this really over pressure?

Thanks!

 

[kaferhaus]

The hole for the button could be oversized....

A better sign is the primer.... flattened, cratered?

Stiff bolt lift usually comes after primer flattening or cratering.... but not always..

 

[deanm]

The primers did not have any pressure signs. The other thing that was a little odd was the first 5 shots had the brass burr, and the last 2 did not.

Thanks for the tip to check the button hole in the bolt face, I will take a close look at it.

Does anybody else ever get pressure signs with 142's w/47.o gr H4350,25 deg. F. temp)?