Unfortunately I have bad news. I shot 50 rounds today, and had two FTF with the 38# spring. Now I'm not going to write this off as weak springs just yet. I'm using 7.62x51 brass from a machine gun, all I shot today were full length sized. It's possible the head space was excessive. Along with that, the primers look awfully deep inside the pocket. I am swagging the primer pockets due to the military crimp. On the next loading I'll neck size only, and I'll measure the primer depth. Firing pin dent's do not look shallow though. I am only using Federal large rifle primers, and these work well in other rifles, they are not defective.
I will say that I shot a couple averages, five-5 shot groups of the Lee 309-170-F with Bluedot. 16 grains was what I have been shooting mostly, and it was again the best today with an average of 2.45" at 100 yards.