I haven't had good luck with Jamison brass in this caliber, bought 40 about a year and a half ago, 14 of the first 20 I loaded split in various locations. Recently got another 20 pieces, loaded two of them (about 80% loads) and both split, just above the case head. Looks like another bad batch. Won't be buying any more.

Karl,

This sounds very bad.

Could it be that your rifle chamber is on the large size, and the dies on the small side??

Just wondering?

I believe that I just got bad batches of brass, I’ve not had any issue with Norma, Hornberger or Nosler brass, or with other lots of Jamison brass. I’ll load 4-5 more from the most recent batch with the same load and see if any of them split.

I loaded a few more from this lot of brass, 4 grains of powder below max listed for a Hornady DGX bullet. I only shot three, all of them split, so I shot 2 Nosler very expensive factory loads, neither split. I won't be loading that particular lot of brass (I do have quite a few other Jamison brass that works perfectly fine). Trying to post a couple of pictures.

I had same problem with some Bertram 375 Flanged Mag brass. I thought maybe I should anneal before first use. But went to Norma with no problems.

Get expensive quickly with new brass failing!

If it was neck and shoulder splits, annealing before use would cure this but splits at the head of the case is indicating something more sinister like incorrect annealing by Jamison when forming the cases or just poor quality brass billets used in manufacture of their cases, eliminating chamber/die issues of course as Saeed suggests.

Measure the base diameter on both cases, could be undersized. I just got a Bertram brass that measured .637 at the base. Most of the case dimensions drawings that I have found online have the gibbs case at .64.

Bertram are nothing but JUNK!

Had some of theirs, so awful they were unusable.

The sides of the cases were different thickness!??

quote:

Originally posted by thecanadian:
Measure the base diameter on both cases, could be undersized. I just got a Bertram brass that measured .637 at the base. Most of the case dimensions drawings that I have found online have the gibbs case at .64.

I measured the split Jamison cases, cases from a different lot, Nosler and Norma cases.
Jamison: .636-.638, both fired and unfired (10 cases)
Nosler: .639-.640 (10 cases)
Norma:.639-.640 (6 cases)

Jamison brass has been flawless in my 500 Jeffery. Guessing the case dimensions don't match up to your chamber. Brass might be wrong

Good brass cases usually can withstand some bulging at the head when fired in oversized chambers without splitting, and will fireform at the shoulder/neck end likewise.
Your Jamison brass is splitting at both ends of the case indicating poor quality brass and/or poor annealing during manufacture. Send it back and get a refund.

jamison had, i have heard, a bad run of brass a couple years ago - these may be NOS from that period