Anyone Shooting Texan .30

Well..... I apologize for the silence. I'm not shooting the .30 or .357 Texan. But I have a friend that shoots the .257, and it is a long range TACK DRIVER! The other big bore models from Air Force are accurate, but not like the .257. My buddy shoots a 71gr boat tail that he casts himself from Arsenal molds. He's making 173 fpe at the muzzle with a velocity of 1050 fps. He's taken down coyote at 300 yards, so YES.... You can easily take down a deer with the .257. I'd probably stick to 150 yards or less on the shots, but the gun is so accurate that shot placement even at those distances is a non issue as long as you have a good range finder. Beyond that and the retained energy of the slug may struggle to humanely kill an animal the size of a deer. 

Griffin slug also makes some GNARLY boat tails in .257. at 90-115gr. Below is a picture of them:

Griffin.1640299270.PNG

 
The .257 and .308 Texan are virtually the same as far as groupings go. I base this on the fact that I have the .308 and my shooting partner has a .257, both with Mad Dog stocks and factory internals. The .308 shoots 110-115 gr. best for flat shooting groups, but the 150 gr. NOE BBT flat nose and hollowpoints are just as good and more suited for hunting big game. 
 
I dont think 1:14 257 texan is enough to balance 90gr BT.. FB yes but BT bullets tend to require more spin to be on balance.. so 90-115gr bt bullets are completely useless unless you wish to obtain custom barrel.

You're correct. The website says it will require a 1:12 twist. I didn't even notice that until you responded. 
 
Sorry did not see this until now. I have a .308 Texan SS and love it! I feel very confident with it out to 200yards (I only have it tuned at 158fpe) for Coyote. I've never tried to shoot it over the 215fpe required for most airgun big game hunting states. So, I can't really input on it at those power levels. When it is tuned to shoot 75grain at 970fps, only a few guns can beat it.