Re: 30-338 twist (did I pick the best?
You would be best suited with a 10-11 twist. 10 if you want to go up to the 240 SMK or Heavy Wildcat bullets. I think you'd be fine with the 11 twist for fairly heavy bullets 200gr and under, VLD bullets or the solid copper TSX's might push the limit if MV is under 3000 fps or so. Error on the side of caution and go with the next faster twist if you plan on shooting heavier bullets in the future or you think it's marginal to begin with, when they keyhole you will wish you had. Most guys using 13-14 twists are Palma shooters with 30" barrels for top MV in 308 Win. shooting 155gr bullets, most anyone else uses a very minimum of 12 twist.
With a 30/338, IMO a 12 twist is borderline with 190's and marginal with 200's, most likely a 180 or possibly less will shoot fine and that's all I'd count on, "especially" if using the long copper TSX's.
The 10 twist would certainly not have killed accuracy either and you pretty much be set to shoot anything you wanted. 11 for what you talk about using would have been my choice, but I still would have went with the 10 in case I wanted to go heavy down the road.