I started doing some precision reloading for a .300 Blackout T/C Encore and was getting FTF about 1 out of every 5 rounds. I originally thought that this was because I added the hammer extension (for easier cocking with a scope mounted) so I got the 52# (increased power) hammer spring from Bellm's and tried a few primer-only rounds. The problem persisted so I removed the hammer extension and the problem persisted.
I was using BR-4 Small Rifle Benchrest primers which should be ok but I went ahead and tried CCI-400 and WSR primers and found that the BR-4 primers must be harder or thicker metal since the indentation was consistently smaller.
With the CCI-400 or WSR primers the problem is gone.
Photo is (left to right) BR-4, CCI-400, WSR
I was using BR-4 Small Rifle Benchrest primers which should be ok but I went ahead and tried CCI-400 and WSR primers and found that the BR-4 primers must be harder or thicker metal since the indentation was consistently smaller.
With the CCI-400 or WSR primers the problem is gone.
Photo is (left to right) BR-4, CCI-400, WSR