Any 7.5 Swiss reloaders here?
I recently bought a K-31 Schimdt-Rubin carbine and am going to send out for some dies and brass soon.

Any hints as to what weight bullets or what powder these rifles tend to like the most?

I use 45 grains of IMR 4064 with my K-31. The OAL is 2.875" with the Hornady 150 SP Interlock .308 bullet (Part # 3031). The Swiss K-31 has a very short throat so be careful about not using a long OAL. With this load I've shot 5 shot 2" groups with the iron sights (amazing for my old bifocal wearing eyes) and I am getting .5" three shot groups with a no drill and tap scout scope mount with an inexpensive 2X7 pistol scope. The Swiss k-31 is an amazingly accurate MilSurp.

Any 150 grain .308 bullet can be used. Hornady has the 7.5x55 covered in their manual. I've been partial to IMR 4895 in mine. Remember, when the current batch of 7.5 brass dries up, you can form them from .284 Winchester.