Mike D Texas
WKR
It's somewhat dependent on how fast you plan to launch them. If you're shooting them in something like a 25 Creedmoor where the speeds could be in the 2700-2900fps range you'll likely want a 7.5tw but if you're shooting them in a 25-284, 25 PRC, 25 SAUM, 25 WSM, 257 Wby, or any other wildcat where velocities will be 3000 to as much as 3300+ then an 8tw will due.
The concern with using faster then an 8tw in things that'll launch these 3100 to 3300 or maybe even faster is the bullet RPM starts getting over 300,000 and at 300K that's when bad things start happening to bullets in flight.
I talked to Hornady and Bartlein quite a bit before I ordered my barrel and both thought an 8tw was the way to go with the 25 SAUM I'm having built to shoot the 134 ELD-M's.
Elevation would have some affect on this. I don’t know about ELDMs but 135 Bergers are marginal on stability with an 8 twist between 3000-3300fps at sea level.
If you have the opportunity I would go 7 twist and be done with it.
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