For anyone interested in powders that deliver the combination of best velocity and accuracy in short barrel Mausers, after years of testing, I can offer the following:
In the Persian M94 (Iranian made version of Brno M29), basically a K98 with 18” barrel:
47.1 grs Varget. Hornady 196 grs SP. S&B brass. WLR primer. 2405 FPS at 5,100 ft altitude and 59F temp. Hodgdon lists Max velocity from 24” test barrel at 2511 FPS with 47.5 grs Varget. In my rifle, Varget delivers 50 - 60 FPS more than any other powder suitable for 8x57 except H4350, which is 12 -15 FPS faster than Varget but not as accurate. YMMV.
In the 1894 Swedish Mauser, 18.5” with barrel extension.
45 Grs IMR 4350. 140 grs Speer Hot-Cor Soft Point. Norma brass. WLR primer. 2568 FPS at 5,100 ft altitude and 59F temp.
Hodgdon lists 2677 FPS for 45 grs IMR4350 in a 24” test barrel.
IMR4350 is not a clear cut winner. Both IMR4831 and RL22 were 25-50 FPS faster at max published loads but not as accurate in my rifle. So both those powders are well worth investigating.
This is by no means definitive but intended to help folks trying to find the load for their rifle. I began the process imagining that faster powders were going to be best in these short barrels. While Varget, a faster powder, turned out best in my Persian, H4350 is slightly faster but not as accurate. It remains worth investigating. For the 1894 Swede, slower powders delivered substantially higher velocities but neither RL22 nor IMR 4831 were as accurate, in my rifle. Recoil with IMR 4831 was remarkably sharp for the 6.5x55. RL22 definitely merits further investigation.
I tested roughly 5 - 8 powders with these common for caliber bullet weights and more with less common bullet weights. The objective was to find what combination offered the greatest effective reach for these short barreled Mausers and for the Persian that’s a Max Point Blank Range of -5” at 250 yards on a 200 yard zero whereas with the same 200 yard zero, the Swede goes out to 264 yards for the -5” drop.
I did a lot of internet searching for best loads for shorties in these two calibers and other than the good advice, that I chose not to believe that slower powders would probably still deliver best velocities in these shorties, there was nothing out there. Hopefully, this helps somebody in search of same.
For cast, my go to in all Military rifles is IMR4227 and I encourage anyone trying to find best Loads for cast boolits in their milsurp to read Ed Harris’ article on cast loads for military rifles.