Just finished up 1st trip to range with my new 22CM. Looking for some help or suggestions.
The Particulars:
Ruger RPR brand new action
Proof Carbon 22" 1-8 twist new barrel
Peterson brass 22CM SRP new brass
VitaVhouri N555 powder
Nolser 85gr RDF Loaded .004 jump basically to the lands
Federal SRP
So I loaded 10 break in rounds at 36gr to check overall function or rifle and load. Avg velocity was 2818fps. No pressure signs. All is good. These are the 10 rounds on the left in the picture.
Then began a pressure test ladder to find where the limits might be. Started at 36.5gr and moved up in .5gr increments to 40gr.
Was hoping to see somewhere around 3100fps before pressure signs. Started seeing the primers flatten and back out at 38gr at 39gr my son said I better stop but I went ahead and put the 40gr in the mag and promptly blew the primer. Other than the Primer signs no other signs of pressure. No sticky bolt, no swipe marks, no extraction issues.
If I go with the last safe load indicated then max velocity is around 2900fps. Kinda disappointing.
Any suggestions if I want to shoot 85-90 grain projectiles?
Do I need to bush the firing pin on a RPR to handle the small rifle primer?
Pics attached. Shows bolt face after range trip and the case heads 10 on left are 36gr. 8 on right start at 36.5 on lower left and the 40gr blowout on the upper right.
Appreciate any input.
Jerry V