Anytime, glad I could help, that’s just a general rule but I have heard guys shooting up to 75 gn and 77 gn projectiles out of their 1:9 twist rates just fine, it depends on the rifle really. If you already have 77 gn projectiles, load them up and give it a try, your rifle may shoot them fine or it won’t. You can see if your target has some funny holes in them if the bullet is tumbling or if there is a nice round hole.
Twist Rate Calculator (Green Hill Formula)
http://kwk.us/twist.html
I picked up a few boxes of moly costed 77 grain HP a while back. I fired a few at an indoor range at about 75 feet. No key holing evident, but I was wondering if that would hold true at longer distances.
Guess I’ll just have to take the 90 minute drive to the nearest outdoor place and give them a try. I will probably just stick with the 62 grain stuff just so I can standardize.
Thanks for the help. Have a nice holiday.