Disclaimer: I'm new to reloading


So I've loaded and fired about 50 rounds without issue. I've been trying out different powders/bullets/etc. using the OCW method and haven't had a problem yet until today. I'll try to provide as much information as I can here.

I reloaded 18 rounds to try out some IMR4350 and the bolt won't close in my rifle. I'm reloading once fired factory Remington ammo.

-Cases are 2.484" in length.
-OAL from O-give to head is 3.843" which is 0.025" off the lands and has been used without issue for the previous 40 or so rounds I've fired that are the same bullet.

-After resizing they're .440" right at the shoulder. (SAAMI spec .441")

When I test the (empty) case here they go into the chamber fine. I believe I've found the problem in that after it is reloaded this same measurement is now .445". With this measurement the bolt will close but is more difficult. Taking the same measurement after I've chambered the round the same measurement is now .443" and it is slightly easier to close the bolt but still more difficult then the empty case.

It seems while seating the bullet it's swelled the case at the shoulder. Why is this happening?