The .025 wall measurement would have to be farther back than 12 inches from the muzzle before I would be worrying about it. Even if it is not too much thicker than that a bit farther back, it should be fine with the kind of loads we want to shoot in Damascus. RST shells in 2 7/8 tens are made down to an ounce of shot (I shoot the 1 1/8) and the pressure is way low. You can buy a lot of RST ammo for the price of Teague liners.