So I recently acquired a Savage 111 in 270 Winchester that is giving me a headache. Its used, made in the early 90's I believe. When I first got it I used a set of Go- No-Go gauges to make sure there were no issues with headspace. The first 4 rounds I ran through it were a starting load of a ladder test, they shot pretty good and without a problem. On every shot with the 2nd charge weight the bolt rotated up just fine, but the bolt took quite a bit of convincing with the heel of my hand to slide rearward, the case ejected fine when it was supposed to. My chronograph showed velocity to be right where I expected... mild. I stopped anyway and took it home for a bolt disassembly and found good bit of crud amongst the parts. I cleaned everything up and put it all back together with a light coat of oil.

On my next range trip I fired the next 3 charge weights (12 rounds total ) and everything went without a hiccup. Velocities were pretty close to where I predicted.

Then the other day I decided to try a heavier bullet weight, loaded up another ladder test, and hit the range. The very first shot of the first charge the same problem happened. Mild velocity, and the bolt rotated up like normal but it was jammed forward bad. I ended up having to take it home and convince it with a rubber mallet.

From the googling I've done Im guessing Ive got a rough (possibly rusty) chamber though I haven't got a chance to check it yet (im at work). That googling also recommended polishing the chamber. The easiest way Ive found seems to be taking a plain old larger caliber bore mop from a standard cleaning kit, slathering it with a mild abrasive (soft scrub, flitz, or bar keepers friend), chucking it in a drill smoothing out the imperfections.

Do you guys have any other ideas what could be causing this? Any other ideas on smoothing out a rough chamber?