Ronald, once you know the caliber and kit you want to use(or parts) then you can get more specific help. There are a few things to think about beforehand, or questions to ask. Does the customer want a real bullet, PR bullet, or a wooden bullet? Do you have a way to hold the cartridge and bullet to drill it? Are you going to clear powder coat it, some other clear coat it, or leave it natural?
I have made a few and can offer some tips, some I got from tutorials here, some I figured out as I went. Ask for 2 pieces of brass & 3 bullets, just in case. Drill the bullets very little at a time, soon as you see the lead climbing the bit pull it out and clean it off. Once you are half way through drilling the bullet, it won't climb the bit so you just have to go 1/8" then pull it out and clean off the shavings. If not you will break off your bit in the bullet.
If you are using real bullets, or one you turn yourself, caliber is unimportant. If you plan to use slimline tips on anything .30 caliber, these help.
Tip Bushing These are especially helpful if you are using two cartridges and the top one is a .30 cal and you plan to put a slimline clip on it. I'll add a pic of a double 30-30.
Don't use a brad point bit to drill either the brass or the bullet! Just don't. If you can find a carbide bit to drill the brass it is costly, but worth it if you plan on doing a few. If the person you get the brass from reloads, ask them to deprime/resize and either chamfer or flare it for you. That will help with seating the bullet. If it is a larger magnum cartridge, you might get away with Sierra or cigar components in it.
Once you get the hang of it you will be doing all kinds of crazy caliber combinations, and maybe even try shotgun shells
Hope this helps,
Mike.
