Originally Posted by Totch94
I have a new 7mm RUM and have only shot factory Remington Ultra Core-loc 140 gr ammo out of it as of yet. It is a very impressive shooter so far (1/2-3/4 inch with this factory load) Now that hunting season is over I thought I'd start a little load development with it. I started this evening by checking the chamber length...WOW... it is so long that I'll never get anywhere close to the lands. I'm trying to load some Barnes TSX 140's up for it and I have always heard that this bullet needs to be right on the lands. Well, it ain't going to happen here! Just wonder what kind of results I can expect with a TON of jump to the lands with this bullet. Thanks for the input.
Actually Barnes will tell you the opposite is true with any of their X bullets. Barnes recommends starting with their bullets .050" OFF the rifling and working from there. I have found good accuracy with TSX bullets as much as .150" off. No - that's not a typo, I'm talking about more than 1/10th of an inch. Barnes X bullets are funny creatures but most often they prefer a jump to the rifling for best accuracy.
One thing I might add: Barnes bullets shoot the WORST when there is any other gilding metal jacket material in the bore. If you think the bore is squeeky clean then run a few patches of an aggressive copper remover (CR-10 or similar) down the bore and wait the maximum time recommended on the bottle. If the patches show any blue/green at all, I'd try cleaning a little more before experimenting with these (expensive) bullets.