I tested the crimp by firing 5 rounds and measuring the sixth round in the cylinder before and after. 8 sample rounds grew by 0.004 to 0.005
The load was Winchester 158-gr JPH and 7.4 grains of VV N-340, CCI SP primer, in a R-P nickel plated case. COAL was 1.580-1.590, which is quite a bit of variation due to the uneven exposed lead portion of these not pretty but cheap Winchester bullets.
Does this reflect an acceptable amount of crimping, or an indication that I may need to adjust the die to crimp tighter?
The load was Winchester 158-gr JPH and 7.4 grains of VV N-340, CCI SP primer, in a R-P nickel plated case. COAL was 1.580-1.590, which is quite a bit of variation due to the uneven exposed lead portion of these not pretty but cheap Winchester bullets.
Does this reflect an acceptable amount of crimping, or an indication that I may need to adjust the die to crimp tighter?