Good on you Pete,
Umm, not sure if a 1 in 13 is too fast or not as I've had no experience shooting light 30 cals out of such a barrel.
My 30 Brx is a 1 in 17 twist specifically for the 110 - 120 grain projectiles & I've been using Copperhead 118's almost exclusively.
Maybe your barrel would be more suited to the 130+ grain pills.....one things for sure, the lighter projectiles wouldn't be "under spun"!
There's a lot of internet chat about 1 in 15 twist WSM's shooting 110 A-Max's so maybe a 125 grain projectile would go ok in your 1 in 13 !?
Might also be interesting to see how a 150 grain ( which is certainly suited to a 1 in 13 ) might go out of a 30 Brx. Might be a tad slow but my "donkey" has no trouble running the 118's up to 3240 fps with good accuracy...who knows what would happen!
The attractive thing about the 30 Br's to me is the barrel life..5000 - 6000 accurate rounds can give you a lot of trigger time & flag reading practise!
I'll see you at the Bay
Belly
Michael Bell