Depends on the bullet, weight of the bullet, auto or rimmed revolver round. Auto rounds have a full length taper crimp by necessity since they head space on the forward edge of the case and can't be roll crimped. Most revolver rounds are roll crimped at the crimping groove on the bullet. .38 wadcutters reside entirely within the case where as various round nose, SWC, truncated cone, etc bullets vary in amount of bullet that is seated. Overall length of the loaded round is important and maximum must not be exceeded. In addition to the crimp, most factory loads use a sealant in the bullet pressing operation that prevents moisture from entering and they seal the primer for the same reason. Some rounds, especially military, you can often see a red sealant around the primer. It wouldn't be real easy to pull a bullet, but I suppose with a vice and a pair of pliers it could be done without blowing yourself up if you were careful. I don't recommend it, however. Besides, you'd bugger up the bullet and case pretty bad trying, I'll bet.
If you just wanna compare, what caliber and bullet weight/design? If I load for it, I could take some pix for you. I'd hate to hear you blew your fingers off when you slipped and hit a primer and you didn't have a trigger finger anymore, LOL.