Having developed some super accurate loads for the 8x57 Mauser but used in the standard 23 ½ inch barrel, I was beside myself when the same load did not work in a long barreled (29 inch) Persian (Czech) Mauser. Checking out the velocity on my chronograph I discovered the long barrel was producing velocities in excess of 2,000 fps whereas the shorter barreled Mausers I have produced about 1,900 fps. I there for cut back my load from 27 grains of 4198 to 25.5 grains and all was well once again and I could use the 25.5 grain load in either long or shorter barrel rifles.
Load was 160 Grain Lyman Lovern with 50/50 alox lube, 1 grain polyester pillow stuffing, Hornady gas check and 25.5 grains of imr 4198 powder. Bullets sized to .325. Used pure Linotype metal.