I am using Dillon 550B & SDB, both set up for 10mm. I weigh each charge, IMR SR 4756 @ 7.9 gr in new Star Line brass, 200 gr XTP's, COLA 1.250". I have several 100 XTP's, so far the gun likes the load so I don't want to change if I have enough 4756 powder to load these XTP's. The XTP's are all the same lot number. Cases are all trimed to the same length give or take .001. Bullet setting stem is locked so it isn't moving. Any ideas on what to do as my OAL keeps changing as much as .050. I have changed the bullet stems to try a different contour no help!
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