Priley
Well-Known Member
Had the same problem with my .280 AI. The full length resize die was pushing the shoulder back to far creating light primer strikes. Once I understood what was happening I backed the die off and no more problems.It should show up when measuring a fired case. Were these handloads? Excessive moving of the shoulder rearward when full length resizing will result in your unfired cartridges exhibiting light primer strikes. Load and fire one case 3 times, measure the shoulder to base and set your FL die to "bump" the the shoulder back .001" - .002". If you don't have the equipment necessary to take the measurements, you can remove the firing pin assembly and the ejector and bump the shoulder back until the bolt just closes with a very light or minimal resistance. Back 50 years ago when I didn't fully understand the reloading processes, I had a rifle getting some FTF's which exhibited light primer strikes. I took the rifle to two different gunsmiths and they correctly said nothing wrong with the rifle. Frustrated, I sold the rifle. The whole ordeal was simply me not having my FL sizer die set correctly and shoving the cartridge shoulder rearward too far.