Have a question on resizing

[Gussy]

Not an oldy but it is a biggy

I got in a horse trade at the Q and ended up with the horse. It's an X frame S&W 500 mag.

I'm used to straight walled cases and reloaded a few without resizing. My brain was not tuned to high pressure smokeless. My thinking being that I'd get longer case life. Since we're all fired in the same gun, no problems were encountered.

But... I'm thinking I should be resizing these cases due to the heavy recoil. It would give a better grip on the bullet.

Anyone have experience with big handgun cartridges and have advise beyond getting my head examined for getting it.