I have been reloading for my 30-30 & 375H&H & 41mag for a few years but I just started with the 30-06. In the first 20 rounds I had 2 that would not chamber. I was using Remington once fired brass and 180 CorLokt bullets. All rounds were proper length. On close examination I found that the 2 defective rounds had a slight bulge at the shoulder that prevented chambering. The other 18 rounds were fine and I don't remember adjusting the dies once I started. I used RCBS full length dies and I use case lube and I followed the directions for setting up the dies. Is this a problem with resizing or bullet seating or both? Is it a sign of defective brass? I have never had this happen with any of the other guns I reload for.
Thanks,
DrScott

Sounds like you are catching the mouth of the case with the crimping lip. I've had this happen a time or two. Just adjust the crimping die up a bit and readjust your seating die and you'll be fine. Make sure your cases are trimmed to proper length also, so they won't prematurely contact the crimping die while seating your bullets.
Another thing that could be happening is you may not be chamfering the insides of your case mouths sufficiently and the bullets, especially flat bse type bullets, may be pushing the mouth down enough to collapse the shoulders a bit before entering the case mouth. Either one should be an easy fix. Let us know if this takes care of it.- Sheister

I bet you are right about the crimping - a habit I got from reloading for lever guns. I'll try no crimp and see how that works.

Thanks.

Yep, I did the same mistake when I started reloading the .30'06 That pesky crimp is no good on that cartridge. Just resize the case and seat the bullets. I had to throw away some accordian cases or messed up heads. What powder are you using and how much?

I am using H4350 and Fed210 primers. I started at 55.5 grains and so far have best group at 57 grains with 4 shots in 1.3" at 100 yards.