Primer cratering
- Thread starter Thepopo
- Start date
That powder load + that velocity + what looks like a little injector swipe or imprint on the back of the case suggests you're at the upper pressure limit. The primer isn't particularly flat and the crater might in part go along with being at that upper pressure limit. Crater's in the primer like that are not a sure sign of pressure as often such a crater is a result of excess space between the firing pin and the bolt's firing pin hole.
Lots of rem 700s seem to do that unfortunately... even sent mine to SAC and had a ptg bolt done and all kinds of goodies. Still craters everything. Annoying for sure. Not sure if it's common in the rpr.
Does your rifle do it on starting loads etc?
Does your rifle do it on starting loads etc?
Jamming bullets causes pressure to spike. The signs of pressure from jamming bullets are not false.
I measured the chamber using the threadlocker method. Running 2.77. So still has space to max COL of 2.82 for the 6.5 CM. One thing that did surprise me was the FPS for the load I'm using. According to Hornady loading manual Staball 6.5 at 43.4 grains is what I should be using to get the FPS I'm getting. But I'm using 42.2. Didn't think the CCI BR4 primer would give me such a jump in FPS.
I checked speed on a buddy's 6.5 Ruger precision rifle with factory Hornady 143 & it was 2650-2660. Had 500-600 rounds on the barrel when checked. These are hammer forged barrels that seem to be on the slow side.
So your beating the factory load by 85 fps with a powder I wouldn't consider to be the best speed powder in a Creed. I'd say your pushing top end of pressure. Firing pin diameter looks big so I'd stick to thicker cup primers like BR4, GM205AR, cci 450, cci 41.
So your beating the factory load by 85 fps with a powder I wouldn't consider to be the best speed powder in a Creed. I'd say your pushing top end of pressure. Firing pin diameter looks big so I'd stick to thicker cup primers like BR4, GM205AR, cci 450, cci 41.
Gordons shows this as being close to pressure. You are likely in the regime where minor things like neck tension, seating depth, etc. can put you over the top.
Also note that different manufacturers' brass can have different case wall thicknesses, which changes volume, which impacts pressure. Someone mentioned Federal brass, but I didn't see what brass you mentioned you are using.
Also note that different manufacturers' brass can have different case wall thicknesses, which changes volume, which impacts pressure. Someone mentioned Federal brass, but I didn't see what brass you mentioned you are using.
Yes sorry i worded that wrong i didnt mean false as much as i ment, the pressure is because of the jam not so much the powder charge.
