I am reloading on a <span style="color: #000099">Dillion 550</span> using LC cases and for the first time, Nosler BT HP 69 grain boolits. I amusing standard <span style="color: #000099">Dillion</span> rifle dies.
I am experiencing wide variations in loaded cartridge OAL. I set seating die for 2.245, but I am getting results varying from 2.210-2.275!
I miced the boolits and their length is consistant +/- .005 inches. That doesn't seem to be it.
I disassembled the seating die and examined the interface of the ogive and the die. The die meets in a very short abrupt way, and not close to parallel with the boolit bearing surface, as I had expected.
I believe the slight variations on where the seating die meets with the ogive is causing these variations. Does this sound logical? I have never had this happen before, but I have also never used anything but 55 gr FMJ standard boolits. These 69 gr obviously have a much more pointly profile.
1) Am I correct in diagnosing the cause of the wide OAL variations?
2) Can anything be done to improve the results? (A higher end bullet seating die from RCBS?)
3) I intend to shorten the long OAL cases closer to the goal 2.245 and just segregate the short ones (< 2.30). Will I see a substantial point of impact variance in these short ones? I suspect that I may not.
The pressure may be increased, as the case volume is reduced, but the distance to contacting the lands should actually not be as far off as the OAL lengths, as the ogive is the consistant distance from the case head.
I will obviously be testing these before a match on Sat. Thanks for the input!
I am experiencing wide variations in loaded cartridge OAL. I set seating die for 2.245, but I am getting results varying from 2.210-2.275!
I miced the boolits and their length is consistant +/- .005 inches. That doesn't seem to be it.
I disassembled the seating die and examined the interface of the ogive and the die. The die meets in a very short abrupt way, and not close to parallel with the boolit bearing surface, as I had expected.
I believe the slight variations on where the seating die meets with the ogive is causing these variations. Does this sound logical? I have never had this happen before, but I have also never used anything but 55 gr FMJ standard boolits. These 69 gr obviously have a much more pointly profile.
1) Am I correct in diagnosing the cause of the wide OAL variations?
2) Can anything be done to improve the results? (A higher end bullet seating die from RCBS?)
3) I intend to shorten the long OAL cases closer to the goal 2.245 and just segregate the short ones (< 2.30). Will I see a substantial point of impact variance in these short ones? I suspect that I may not.
The pressure may be increased, as the case volume is reduced, but the distance to contacting the lands should actually not be as far off as the OAL lengths, as the ogive is the consistant distance from the case head.
I will obviously be testing these before a match on Sat. Thanks for the input!
