model 16 reload problem

I have a model 16 ss in 270wsm with 24" barrel. It shoots Remington 130gr sp rounds great but I can't get it to shoot barnes 140tsx at all they keyhole no matter what powder load I try. I called Savage and gave them the serial number and was told that the barrel is a 1 in 10 twist. when I run a brush through the barrel it only rotates twice making me think that it is a 1 in 12 twist. Any help with this problem will help. I reload and want to work up a 140gr load with barnes tsx bullets.

You on the high or low end of the powder charge scale? hard to have a 1 in 12 if they do not make one.
seating depth? Some Barnes bullets like to jump to the lands.

makes no difference which end of the powder load i am on and seated .05 off the lands

Long as you own them, try hot and deeper. Boat tail down below the neck. If you had pressure signs back off a bit as the bullet deeper in the case could compress the load or raise pressure a mite.