A fellow 500 Jeffery shooter told me recently he has a 60% fallout rate with Jamison brass. I asked if loads were worked up in other brass and he didn't know.

I have a nice stash of 500 Jeffery brass(I WILL BUY ALL THE NEW SAKO I CAN FIND AT A REASONABLE COST).

I weighed a bunch of new brass after sizing and trimming and discovered the following. Draw your own conclusions.
Weight is in grains.

Norma:
319.7
318.1
318.6
319.1
319.8
318.7.

HDS:
301.9
306.1
303.5
304.4
304.0
303.1.

JAMISON:
356.9
354.0
356.1
354.2
356.6
354.8.

SAKO:
316.8
316.9
316.4
316.8
316.7
316.0

Develop max loads in HDS and then use Jamison and it might cause a problem!

Please define "fallout rate". I assume this is some kind of failure, but of what nature? Cracked necks? Blown primers? Blow throughs at the pressure ring? Did these "fallouts" result in damage to the gun or shooter, or did they result in a jammed rifle, etc?

Just curious as to the nature of the failure because I have some Jamison brass that I have loaded but not fired.

I never mix rifle brass. I only use the headstamp that was used when the load was first developed and have never had problems with accuracy or pressure.

Case capacity matters far more in high pressure cartridges than it does on low. Obviously. Just don't mix them.

The pictures he sent show lengthwise cracks about 1/2" above the extractor groove. They look like they are less than 1/4 inch un length. Says it only happens with Jamison brass.

I believe the heavier cases would have somewhat smaller internal volume, so, with the same amount of powder, the heavier cases would generate more pressures.

Kind of like higher compression in an engine.

I weighed a bag of new Winchester brass, in 243, some time ago. After trimming all of them, 13-14 pieces weighed about 170grs, while the rest of them weighed about 158grs.

quote:

Originally posted by drewhenrytnt:
The pictures he sent show lengthwise cracks about 1/2" above the extractor groove. They look like they are less than 1/4 inch un length. Says it only happens with Jamison brass.

That seems unusual since cracking in that area is usually circumferential. However, I've heard some similar complaints regarding Jamison brass from others. Sounds like the brass may be a bit brittle in the head area, and/or the chamber somewhat oversized.

I use my rifles to hunt with so never weigh cases, I mean shooting bufflo at under a 100 yards does not equire that..I do use the same WW brass, PPU, REm mostly and keep it seperated..I require a hunting rifle to shoot a 3 shot one inch group, and some of mine will do the same with 5 shots..

It is useful information. Sometimes the results have different effect. Out of curiosity I did a bunch of 30-06 after I got a 5-0-5. It turned out I was using my heaviest brass in my 338-06 . To keep from mixing with 30-06 I used only that brand . I found a 338-06 could use that tiny bit more capacity. Powder companies, luckily, brought out powders that were two grains faster than 4350 and four grains slower than 4064.

We always do.

Yesterday a friend reported that he was weighing Lapua 308 brass.

All within 2 grain, except one that jumped 11 grains!

As a matter of course, we weigh all brass, and segregate them by weight for each rifle.