Take jethunter's advice on this.
Look the cartridges up online before you start feeding 38 S&W, or 38/200 cartridges into these fine old revolvers.
Use black powder loads that the cartridge and revolvers were built for, if you want the best results.
For those not familiar with "heeled" bullets, look them up, and you will see why you can't get away with regular bullets.
The best way is to slug the bore of your pistol, check cylinder diameters, etc and match things up.
For my Webly No5, I use 380 acp dies to make up ammunition for it. The 380 sizer die, works perfectly to size the case and case mouth to accept the heeled bullets I cast in my custom mold, and hold them with enough tension while firing.
Not enough tension or light crimp, and bullets will start to work out of the case, causing the cylinder to be jammed.
Bores in these pistols vary quite a bit, as to cylinder dimensions, so custom molds are a good way to go.
I've never seen hollow base, heeled bullets, but that doesn't mean they don't exist.
jethunter would know more about that.
I use 38S&W cases, which are a mixed lot.
I've turned the rims so their "thicknesses are the same, and they allow the cylinder to turn smoothly.
I also trim the length of the case just a bit for my pistol because the newer cases tend to be a bit long for the chambers in my pistol, but I've see a couple of Belgian made pistols that don't need any of this to be done.