All great advice thus far. I'd just like to add that the usual 'Cowboy' .45 Colt loads are anemic when compared to the 'old' blackpowder loads. While they would just break 1,000 fps from a 7.5" barrel with a 250gr LRNFP, typical modern smokeless loads run 750-800 fps. For example, the excellent - and affordable - Georgia Arms 240gr LRNFP .45 Colts made 753 fps from my 5.5" BH (I didn't have my RH then!), very similar to the max 7.1gr load of W231/HP-38. The nice outcome of using their loads is you gain some nice once-fired Starline brass. BTW, changing to a near max load of 6.1gr for Titegroup powder gave me a cleaner revolver - and another 100+ fps with a 255gr LSWC. Reloading can be a lot of fun... but always be careful!
BTW, I had never touched a reloading press when I ordered my Dillon 550B over four years ago. I had amassed 2,700+ .45 Colt empties (I liked GA Arms prices, too!), and reasoned the equipment would be 'paid for' by ~2,100 rounds... wrong attitude, I found out quite quickly. Reloading is a new hobby... and, you can shoot a lot more for less money... but only if you have the time to reload AND shoot! Some folks claim I only go to the range to 'make' empties to reload... they may have something there. I now make 7.62x38r (1895 Nagant), .32 S&WL/H&RM, .38/.357M, .44 Russian/Special/Magnum, .45 ACP/AR, and .45 Schofield/Colt - after 'starting' with .45 Colt - my then 'only' caliber (Yep, I added all of the rest in four years!).
Back to your .45 ACP conversion of a RH - please don't! The very best way to launch .45 ACP's from a DA revolver is via a 625/25/1917 S&W. A standard 230gr FMJ 'ball' ammo round would likely make 850-870 fps from your 5.5" RH. You won't be able to use the moonclipped .45 ACP's or .45 AR's (Auto Rims) without some real metal removal from the cylinder's backside, resulting in your .45 Colts then also needing moonclips. The KE increase of the ACP/AR's (21 kpsi) over SAAMI spec'd .45 Colts (14 kpsi) isn't worth it... you already have a .45 Colt +P capability that will trump any .45 ACP/AR load.
All of that said, plinking with .45 ACP's from a revolver is big bore/low recoil fun. The Ruger SA .45 ACP/Colt convertible may just be the answer, as it has separate cylinders which provide the appropriate headspace for their respective cartridge, and permits the SA ejector unloading, too. It was my revolver entry path years ago - and started my .45 Colt craze. With a DA, ie, like my 625JM revolver, you have to use the moonclips, admittedly much faster than any speedloader, with the ACP's - the thicker rimmed Auto Rims are used just like any other rimmed cartridge. Enjoy your .45 Colt RH!
Stainz