Loaded 300 winmag sticky in chamber

[ArmyJerry]

Have about 200 reloaded rounds of 300 wm, they are FC mil once fired, I fl sized them and trimmed to length, but after going to the range they wouldn't chamber the last 1/8 th inch. I ordered the Larry Willkis collet die an sized about 100 empties I had on hand. It moved the case right above the belt from 515 to 510 and the shells now fit the chamber fine. The barrel is a 28" CBI Match chamber on a Savage so I expected it to be tight. I would like to get some new win brass but none to be found so I am stuck with this once fired FC mil brass, the pockets are not as tight as the win cases I do have but tight enough. My question, should I use the Larry Willis collet die on the loaded rounds or take them apart and size them? The empty cases I sized had used very little pressure to squeeze the case into spec.

 

[sakobob]

just a question, what does it measure above the belt after it is fired in your rifle.
and as far as sizing the loaded round, you will have to asses that risk.

 

[FLIGHT762]

I bump shoulders back if needed on loaded ammo using the Redding body die. I have a Willis collet sizer for belted magnums. I don't think there is any risk in sizing your loaded ammo with the Larry Willis collet sizer. Just use a good lube as needed. Did you use a gauge or measure your shoulder bump to see if that is also contributing to the chambering problem?

 

[Xtremegunnr]

Yeah, in my experience sometimes just neck sizing without bumping the shoulder is not enough. The brass somehow is bigger once ejected than the chamber...who would have thought.

 

[ArmyJerry]

Thanks for the help gents, I ran them all through the LW die, the cases all fit perfect now, snug but no prob getting them all the way in there, even the other non mill spec cases are more consistent now. I will try just a neck bump on the next cycle of firings this weekend.