I load for a buddies Kimber 22-250,while at the range yesterday,2 of his loads would not chamber in his gun.These cases were done fireformed to his chamber and then reloaded with a set of Lee Collet dies.Being as how they were sized with the Collet die,there was no expander ball to catch and pull the shoulder like some other full-length dies.I took the 2 rounds and shot them in my VS and the chambered fine so my chamber is apparently more obese than his.These cases were trimmed to minimum length so I know they were not too long.Anyone got an explanation for this.

Were these cases full length sized or neck sized. The usual reason for this is from neck sizing a case that was fired in another rifle. Measure your head size and see if it conforms to specs. You weren't using Lapua cases were you? Sometimes their cases have to be full length sized before firing as they often are a bit larger at the base. If you're full length sizing make sure the die bottoms out on the top of the shell holder. Hope you get it figured out. Best wishes.

Cal - Montreal

The Collet die neck sizes only.It is Winchester brass and they have been fired in this gun only.

It isn't uncommon to have a factory chamber be eccentric. If the brass is not put back in the exact orientation in which it was fired, the out of round cartridge won't chamber.

I've also had compressed loads expand the brass enough to prevent chambering. It doesn't take much. No other guesses.

Any chance that the rounds involved had bullets that were not seated quite as deep as the rest of the batch. If so your rifle may have a little longer throat. Could happen if you got distracted while seating bullets...short stroked a couple.

Or perhaps previous firing was a little "Hot", making necksized brass tight.

Another possbility would be a little dirt on brass or in chamber that got wiped off before brass got to your gun, or out of the chamber before you tried another round.

Just "educated" guesses based on past experiences.

There is a possibility that when seating the bullets that you may have put a slight crimp onto the two rounds and therefore they may not let your friends rifle close on these rounds. Your rifle may have more tolerence and therefore allow the rounds to fit and fire. Only a guess from passed similar problem.

Any or all of the above, plus: If the initial firing was with a very high pressure load, the case may stretch enough that it will not rechamber if neck sized only.

It is more likely, however, that the case was "bumped" in the bullet seating process which caused a bulge either at the neck or shoulder that is beyond the tolerance of the gun's chamber. Conventional seating dies should ALWAYS be backed off so that the g*&d$%^n, f&%$#@g useless crimping ring doesn't touch the case neck.

My guess is that either the dies were not properly adjusted or chamber "A" is larger than chamber "B".

It's pretty easy to push a neck in with a collet die if it doesn't open up all the way, for whatever reason. I have several on my bench as examples. FWIW, Dutch.

was he shooting boat tail or flat based bullets? If flat based and the neck of the case wasn't properly chamfered, the base could hang on the lip of the cartridge enough to bulge the shoulders of the case.

I would check die adjustment also, it is easy to knock the shoulder down just enough to prevent a round from chambering with the collet dies (I found this out on a first hand basis).

I had this happen once also. I had a slightly high primer that got by me. Cases would not let me close the bolt.