WARNING: Check the loading manual.

[Larryjk]

We all think we are experienced reloaders. Two days ago, a friend called to ask if I would look at his rifle? He fired a shell that apparently was TOO MUCH and he couldn't get the bolt open. He brought the rifle to my shop. It is a Kimber Tactical in .308 Winchester. The bolt handle was up (bolt unlocked) but he could not get the bolt back. The handle was bent back from him hitting it with something. He had thoroughly lubricated the barrel and chamber area with Kroil to no avail. I put 1/4 inch drill rod down the barrel to the base of the empty cartridge stuck in the chamber and began tapping it with a machinists hammer. It didn't move. I switched to a 2 lb. hammer so I could get more force without a mighty swing. It moved back then without much force. When I could see the entire case was in the ejection port, I removed it from the bolt face. There didn't appear to be any damage. He was sweating blood because he had done this on the second shot. He said it was 46.5 grs. of W748 behind a Hornday 168 gr. bullet. (I am giving the brands because the problem was not with the manufactures of the products involved.) The R-P case was now ready for a shotgun battery cup primer. He couldn't understand why it hanged up so tightly because the shot before didn't. It had been 47 grs. of W748 and the case was also ready for a shotgun battery cup. I asked him where the he-- he had gotten the data for those loads. He said he thought he had been using that load in a prior rifle.
We went into my office and got out the last two Hornady manuals; Edition 7 and 8. W748 is not listed for the 168gr. bullets. The max. load for a 155 grain bullet is 46.7 grs. of W748. I told him at least he should have started at the LOW end of his test loads and work up instead of the TOP DOWN. I also told him he was very da-- lucky he still had a good rifle and all of his features. I let him copy the data from my manuals. I told him to go back to about 43 grains with the 155 gr. bullets he had and work up, watching the primer. At the first sign of flatness (before a primer smeared over the case head), drop back a half grain.
I see this type of trouble far too often. Use a manual to work up a load for your rifle. If you are looking for magnum velocities, perhaps buy a magnum.