Good info already given...

several things I didn't see mentioned... Difficulty sizing is indication also your brass is expanding too much...either a slightly oversized chamber or you are redlining your velocity, with way increased pressure when firing...

my sizing regimen is to neck sizing and deprime with a Lee Collet die... then if it chambers too snugly or with difficulty, then I bump the shoulder back with a body Die..
Got one in 7/08 that works well both for the 243 and the 260.. a long with a 7/08 if I shot one...

spindle out of the 260 die also works well for a 243 body die...

I hear a lot of the ways guys lube stuff, which all seems to difficult for my tastes...I was self taught to reload so I found what worked for me...

I use this for lubrication... friend is a dealer...can is like $8 and lasts me for about 4 years or more.. and I do a lot of reloading...

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and how I lubed them is in a blue camping frying pan I picked up at Bi Mart for $7, like 18 years ago or so...

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spray lube the pan as needed, and when not in use, hangs on a hook off the side of my reload bench...

toss 10 to 15 pieces of brass in there at a time... shake it around a little like we use to do to a pan of jiffy pop, popcorn..

Works real well, is not a big mess... definitely gets the brass lubed well.... stuck cases are a thing of the past...

a little prudence on the powder scale contributes to that also..