I reviewed a few of the past threads on this and am not sure I've found my exact solution yet.
Curious to the groups thoughts on my issue. Facts below:
-built a new CF 7 WSM off a savage SA. Have roughly 100 rounds down it. Half factory loads. Half virgin brass (non sized before loading) hand loads. And about a dozen sized second firing loads (where problem is).
-factory loads shot great a little bit of a sticky bolt on some but nothing that worried me.
-the virgin brass (Hornady) pressure work ups to alliants max pressure for RL26 (71.2 published) I got to 69.2gr before I saw a light ejector swipe and slightly heavier bolt lift. I backed off to 68.8 and shot 20 rounds all great no issues no pressure signs.
-I bought Forster FL Die set and used a RCBS shell holder. I cut all once fired brass to 2.095" (max is 2.10" trim is 2.09").
-I noticed on FL sizing the unloaded cases wouldn't chamber smoothly when the die was fully seated against the shellholder (per instructions). Research showed likely a mismatch issue with RCBS vs Forster (they only use universal holders with theirs press from what I can tell).
-I shaved .002" off the top of shellholder allowing the clearance to fully size the back of the case and it chambered perfect.
- I prepped mouths. Loaded from 68.3 to 68.8 to double check pressure with the sized brass.
- Started at 68.3 at the range. Roughly same velocity as with virgin brass (20fps more but 80 rnds through). BUT very heavy bolt lift (almost needing mallet).
-switched to factory load. No issue. Switched to original 68.8 virgin brass. No issue. Then back to 2nd shot handloads. Heavy again.
-Came home rechecked headspace using go/no go. Good.
-checked shoulder using comparator and the Hornady modified case(for COAL measurements) measured 3.972", once fired measured 3.971-.973", twice fired same, and FL resized measured 3.965".
-measured OAL of fired brass and it was roughly 2.105" (.01" growth from sizing/cutting).
So initial thought was a pressure issue. But would be a bit weird using less powder than original load and getting similar velocities, but haven't ruled it out.
Other thought is something with my Die setup. I find it a bit weird it is sizing the shoulder back .07" (never measured on any other round so not sure that's normal for FL die). Also find is a bit strange to see .01" case growth with one firing. Maybe related?
Thinking the next step is to load down to maybe 67 and work up from there BUT like many, pretty low on my CCI250 primers and hate to blindly troubleshoot and waste some not knowing when more will be had.
Appreciate the teams thoughts.
