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.
Any of the 4350 powders can be used in the 7.5 Swiss, that is IMR 4350, AA4350 and H4350. Buy by price.
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.
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
Notice the grease ring around the bullet of Swiss service rifle ammunition. This ring has approximately the same consistency as the beeswax mixture used for a toilet bowl wax ring. The Swiss did this to improve accuracy and accuracy life. I was surprised to find that the Austrians, Italians, and Russians all fired greased service rifle bullets prior to discovering a decent bullet jacket. They all did so to prevent fouling and heavy wear. The Swiss kept this practice up to the late 70's, and apparently, some Swiss target shooters still grease their bullets.
The only real difficultly I encountered was establishing the base to shoulder distance. No one sells a 7.5 Swiss case gage, so I used the Sinclair version of the HORNADY HEADSPACE GAUGE KIT, BODY w/5 BUSHINGS.
http://www.grafs.com/retail/catalog/product/productId/7288 With this gage I was able to properly set up my sizing die and only push the shoulder back 0.003".