Jordan Smith
CGN Ultra frequent flyer
- Location
- Calgary, AB
Steyr-Mannlicher uses a 1:8.6 twist and mine shoots 150 Partitions in 1/2" at 100 and 175 Partitions into even smaller groups.
Jordan - where does Berger talk about the 195? I haven't seen much on it outside of the Long Range Hunting forum - and there, according to Bryan Litz, the +1.6" long 195gr will need at least a 1:8.5 twist. I suspect it will depend on barrel length too, and on whether a fellow is using it for hunting or target shooting.
Eric Stecker, Bob Beck, and Bryan Litz have all contributed to various threads on the LRH forum, and comments were made regarding the Miller stability formula showing that a 9" twist will stabilize the 195 most of the time, unless you're at sea level in dry, cold conditions. I can't remember if it was Bryan or Eric, but one of them agreed that 8.5" is only going to be necessary in the worst conditions, but since they have to cover their bases, 8.5" is the minimum recommended twist. If throating a barrel for the 195, I'd go 8" twist, since you never know what super bullet might come out next, and a little reserve twist is never a bad thing.