I have had the same experience in chamber varations. My barrel that I kept, I've had 4 of them, and shoot is an old tapered barrel with the front sight sweated on and the 6 groove 1:14 twist barrel. It seems to have the chamber cut a hair deeper than my other 30 H's have been. Some of the barrels gave a little pressure with 24.0/H4227/125 BT but not with this one. It also shoots that load just under 1" @100 when I do my part. I also have changed the locking bolt , orginally solid bolt , to a split one that fits the frame I use it on VERY tight. It will give you a sore hand opening the action if you shoot it much in a day. You always have variation in mass produced , or semi mass produced items in TC's case . I bet you could work with your 30H and get it to shoot but you want to start with oversized brass and do the drill to make the brass correct that is the most important thing to consider in the Herrets IMHO. Jim