Re: Loads for a semi-auto
Not familiar with the 940s, so I'd have to do a little research to see what the action type is. H&K has long used the roller-locked delayed blowback, and if that's the case, it will eliminate many of your concerns here. For a gas operated design like the Garand, port pressure is a major issue that has to be considered when loading, or damage to the rifle is a very real possibility. Regardless, a medium burning powder like IMR4895 or 4064 should be perfect for this. Any of the other powders of similar speed (Varget and Reloder 15 come to mind) should also be ideal. The standard load for the Garand with the 168 was usually around 46-47 grains with the 168, so you might want to verify, reduce a bit and work up from there.
Hope this helps,