Seat to the crimp or OAL of your specified data and component recipe using the bullet you choose.
Some Hornady and Speer bullets have two cannelures; seat the bullet farther out per their instructions in revolvers. If they do not seat out, a reduction in charge is in order, also upon their instructions.
Yes, the 180 .357 PT Gold HG is a handgun bullet, as can be the 200 gr Hornady SP (prolly not in a 357 wheelie
)
Mac is correct, and I linked to the wrong page. Most of those jacketed bullets run .357-5.
However, sometimes a .357 barrel can measure as small as .355-6, a 44 Mag can have a tube of .427 and 45 Colt/Casull can be .450. Sometimes the throats AND barrel groove can be smaller than the bullet.
Yes, there will be pressure differences that data cannot account for, so work up. Basically, within certain parameters, working up a load IS an experiment, even when you have data for it, because its not from your gun.
I like casting my own, some with dual crimps and in some cases lube grooves make a fine crimp groove; and yes, I like to seat out as far out as I can.
Getting started though I would pick your bullet and find some published loads, follow their instructions, work up and have fun!
