Get 7.5 Swiss cases.
Back when the only 7.5 Swiss cases were Norma, at $2.00 each, I sized and trimmed 284 brass.
It worked, but the rim was smaller. So the occasional case would fall off the bolt face during extraction. Not a problem if you want a single shot rifle, but otherwise it will cause a jam, and you have to get your fingers in the action to get the case out.
I conducted some load development for the 7.5 Swiss. I have never purchased Swiss ball, but a bud gave me a chance to shoot some across my screens.
AA4350 gave excellent accuracy and just about duplicates Ball velocities with 51.0 grains and a 168 Nosler Match bullet. As you can see 52.0 grains produced velocities over Ball, so I do not recommend that load. It is here for reference. Incidentally AA4350 is Accurate Arms copy of IMR 4350, they told me grain for grain it gives the same pressure curve. Buy whatever cost less.
Instead of AA4350 I am shooting surplus WC852 in the 7.5 Swiss. This is a ball powder, and I purchased my lot from Jeff Barlett at GIBrass.com . It turns out Accurate Arms purchased a 90,000 pound lot of WC852, faster burning than Jeff’s lot, and now it is labeled as 2700. My lot of WC852 shoots extremely well, was dirt cheap, and I am using that up. But if I did not have the surplus powder, I would give IMR4350 or AA4350 a go as it shot very well.
I think this cartridge likes powders in the 4064/4350 burn rate range.
Code:
[SIZE="3"]7.5 x 55 Swiss Model K-31
AP11 Swiss Ball headstamp DA 78
24 Mar 04 T = 70 ° F
Ave Vel = 2565
Std Dev = 11
ES = 23
Low = 2551
High = 2574
N= 4
168 gr Nosler Match 51.0 gr AA4350 INDEP brass and primer OAL 2.850
22 Dec 01 T = 58 ° F
Ave Vel = 2536
Std Dev = 17
ES = 45
Low = 2510
High = 2555
N= 9
168 gr Nosler Match 52.0 gr AA4350 INDEP brass and primer OAL 2.850
22 Dec 01 T = 58 ° F
Ave Vel = 2624
Std Dev = 31
ES = 72
Low = 2588
High = 2660
N=5[/SIZE]