I had my Marlin 336 in 30-30 at the range last night and put six rounds through it and on the sixth shot the action jammed and was solid (I was pulling pretty hard on the lever but it would not budge.
I got it home and managed to lift up the extractor on the bolt and it opened up with ease, I then had to push the empty out of the chamber with a rod, it took a couple of bumps but nothing too significant.
the gun cycled as normal without a round and so I put the empty case in the mag and cycled it and it took a little extra pressure to close the bolt the last 3/8 of an inch of travel and again the action was locked up and would not open.
If you push the rod down the bore and "bump" the cartridge as you pull the lever it comes open.
My rounds were reloads (as most of them have been for the last few months since getting the 30-30) and have been reloaded maybe 3 times now and I checked 2 empties I had and they both have a very slight small bulge about half an inch up from the rim on the cartridge, I pulled and weighed the charge on the 3 rounds I have and all were bang on at 31gr of IMR 4320 and also OAL was good at 2.55" (150gr RN)
I have loaded all my 30-30's with a lee loader and then used a crimp die as I was told this is a must for an underlever with tube mag.
I am assuming the small bulge in the cases is causing the cartridge to jam in the chamber and the lever just cant put enough force to pull it out but is this due to me not full length sizing? (as the lee loader only neck sizes) and why would I be getting this small bulge with the sedate loads I am using? from my lee manual I could go up another grain without issue with IMR 4320.
I am not familiar with 30-30 and at first didn't know that the rounds had to be crimped so I just want to make sure I am not missing anything else on the need to FL size the brass etc.
Any help/advice welcomed.