Thread: Different brass strength between batches?

Greetings Larry Goat,
Yes that one on the right is way too hot and I suspect the middle one is as well. The Hornady 90 grain ELDX is a long pointy projectile and the Hodgdon/ ADI data is worked up with the Speer 90 grain spitzer flat base and this is old CUP data not PSI. When the pressure measuring system was changed the .243 max pressure was lowered due to erratic pressures in the .243. Your ELDX projectiles are likely seated deeper due to the mag length so case capacity is less and pressure is higher. It is also possible, likely even, that your AR2209 is significantly faster than the batch used by Hodgdon to work up their loads. I found this in my 6.5 recently and Cigar above is matching book velocities with 2 grains less powder. This is exactly what I found. I don't think your cases are the problem, your loads are excessive. 42.4 grains matches the Hodgdon data for the 85 TTSX and the 95 grain Partition. A chronograph would have warned you that you were too hot. Sorry to give bad news.
Regards Grandpamac.