I just ran into a problem I have never seen. So please help me out. Been loading for my 300 WSM for alittle over a year now with not to many problems . But I have some cases that will not chamber easily into my gun ,seem to be overly snug. This is the second time that I have loaded this brass . I have checked the case lenght , the seating depth and anything else I could think of . So maybe you guys could give me some info on what to look for . Thanks in advance.

P.S.

It is a Remington Rifle and I am using Winchester brass .

Are you full length sizing or neck sizing? If full length, I would check to make sure the shoulder is being bumped back .002. Stoney Point makes a nice, inexpensive tool to check it with. If neck sizing, start using the full length die. The shoulder will get longer with more firings and reduce headspace which will do exactly what your cases are doing now. Some like to partial FL size, but when the body is sized down, the neck gets longer until the die contacts it and pushes it back down. These cases are also kind of thick, be sure to lube each one. If you dont have a way to measure headspace, try moving the die downward if there is room and see if the case will chamber easier. Hope this helps.

The shoulder might have crept forward a little bit. Try turning the sizing die in 1/4 of a turn at a time until the brass chambers easier.

FC363 types faster than I do.

Also check that your seating die isn't screwed in to far and hitting the mouth of the cases as its seats the bullets. If it does it will buckle the case a little bit and cause it to fit tight just behind the shoulder.

7Mag- Fjold and FC363 hit the nail on the head with the shoulders. My 270WSM did the exact same. Bump the shoulder back slightly and you will be good to go.

1/4 of a turn on a sizing die is MUCHO ALOT. Try just tightening it down very little....like about 1/32nd of a turn.
I have the tool mentioned above and would highly recomend ANY RELOADER get one. It makes setting up dies for proper headspace a breeze. You only want to leave about .003 or so headspace on your brass. If I remember right a full turn on a sizing die is equal to about .060" or maybe more. Thus 1/4 turn is HUGE if you are already close to the right headspace. Keep making very small turns on the
die till you get ez chambering.

From time to time I've ran into that problem. More than once I found that when I was pulling the neck over the sizing button I was stretching the shoulder out a bit. Lubing the inside of the neck and polishing the sizing button corrected the problem. roger

Thank each of you for your help. I will be sure to do as you said and see what happens . Will let you know. Thanks again.

I just wanted to let you know ,yah hit it right on the head. I screw down the sizing die and the brass chambered like slik. Thank each of you again , I am a happy camper.