Does anyone know what rate of twist the original oberndorf mauser sporter barrels had? I am specifically interested in the 7x57 caliber guns with 24" barrels. I believe the military guns had about a 1:9. My custom 7x57 has a 1:10 and groups factory Norma 150gr very well but my old sporters don't like them as well.

European sporters favor long, heavy bullets. Try 170+ grs. for a 7mm bore.

KurtC is correct, the older sporters and military rifles were 1 in 9" to stabilize the long 175 gr. FMJ's and softpoints.

Think I am going to try the Sellier & Belot 173 grain factory load. I don't know how good that "semi-wadcutter" type bullet is on whitetail size game but, I know how to find out.