I never had much success with bullets below 129 grains in the old M96 or M38 rifles. I suspect, the generous chambers and long throats were more the problem than the fast twist rate.
If light bullets are spun to fast, they may start to separate from their cores. That is the rumor anyway. On the other hand, I shoot 95gn Hornady VMax at over 3100fps out of my Tikka T3 and it shoots them like lasers. Funny thing though. The T3, is a much stronger action than the M96 and it has a 21.5in bbl. The loads I've used, will not give me more velocity than slightly over 3100fps, even though it's obvious pressures have risen. I suspect, that's because of the shorter bbl. There really isn't any need for more velocity in any case, I was just curious how much I could get.