Only loads with deep seated, short, light bullets. The inside length of the unaltered Kurz magazine is 69 mm = 2.71”, while the max cartridge oal of the 6.5x57 with 10g = 160 gr bullets is 82 mm. You cannot use loads with the bullet protruding more than 12 mm = .472” from the case mouth and have them work through the magazine. This may lead to the next problem: Proper 6.5x57 chambers conforming to CIP standards are cut with a long, 30 mm = 1.18” minimum throat to accommodate the old, long roundnose bullets, coal up to 82 mm. So many 6.5x57 barrels don’t show good accuracy with short, pointed bullets. This is the reason why the 6.5x55 SE with it’s much shorter 14.10 mm min. throat has made inroads into German hunting rifle use. The Swede is often more accurate with light, pointed bullets, while it is a twin in all other ballistic aspects.