My last run of 348 ammo with the 250 woodleighs were a little warm and had slighty sticky ejection, 51.5gr imr4895. Pulled the bullets and reloaded them with 49.5 imr4895. Grouping went from 1-2in to 6-8in. Only thing i could think of to account for such a drop in accuracy was that I used the lee factory crimp die, set to lightly crimp. Went home reloaded 5rds with factory crimp die and 5rds with standard crimp accuracy went back to normal.
Interesting result. I use the Lee factory crimp die almost exclusively in my tube feed rifles including my 71 and have never had such a result but each rifle is a law onto itself. H414 in my 348 really shoots well, but your results with IMR 4895 leave nothing to be desired. Beware Jamieson brass, it's good but holds much less than Win brass and can bring some pressure. I load 4 grains less powder in the J brand.
I was suprised to have such a dramatic change in accuracy. Have a run of 30-30 ammo I just loaded up using the lee crimp die, as soon as wind stopps blowing going to range and see if same thing happened.
Same here. I have and use them in just about every caliber I use. Did your powder lot differ?
No, same everything. Loaded the run, went to range and found the accuracy problem. Pulled the bullets and reloaded with same powder/bullets. Without using the factory crimp die and accuracy was back to normal. Did a run of 30-30 using factory crimp die that will hopefully shoot today to see if had same drop in accuracy.
I've only used the FC die in 348. Works great and accuracy with irons was 3/4" at 50 yards. That's GREAT for me!
I also use the Lee FCD for all my leverguns..25 35, 25 20, 30 30. 307w, 356w, 444,etc and love it !
Do you trim your cases to the same length? When reloading a few days ago I noticed that the crimp tension varied with some shorter cases I had put into the mix. Wonder if variable length cases could create inconsistent crimp tension and lead to some accuracy issues?
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My Lee Factory Crimp Die sits on the shelf gathering dust. My results using the FCD were very similar to the OP's results. The LFCD seems to distort the cast bullet which affect accuracy. The LFCD work great with Jacketed bullets with no crimp groove but is death on cast bullets. YMMV