Steel vs Brass frame-a long winded subject over the years. Me, myself, and I prefer steel-for looks and strength. There has been alot of discussion over the years between the two metals for a percussion frame. This coming Feb (2025) I'll have been in the cap and ball shooting fun and interest for 53 years. Even back in 1972 the cons were that a brass frame will shoot loose after a time. Alot of evidence and reports of it. There is alot of reports of those that have shot a brass frame for years with no problems. From what I've read over the years alot of brass frame problems have come from those that have been shot alot and/or from shooters stuffing as much black powder as possible.
A brasser is usually cheaper than a steel frame like model, but not significantly so and if I were new to the game (or been in it awhile), the amount 'more' wouldn't stop me from going steel. Both for looks and strength. There has been mention on this thread of 44 caliber 1851 Navy framed models. IMO nothing wrong with them, all that 'period correct' talk IMO is worthless. My first was a Euroarms 44 '51 model. Had problems with it as far as timing, caps available back in the day not staying on, falling into the action. Back in the early days there wasn't much for caps available, even though they were .85 to .99 cents per 100, just didn't have the availability of them, nor after market nipples. Ya shot what came on the gun. That gun met a sad ending being accidently placed with items destined for a burn pile. Loved the '51 model and 44 caliber so much bought a Pietta '51 in 44 around a dozen years ago, one of my favorite of a dozen plus cappers (2nd Model Uberti Dragoon favorite).
I prefer Open Top Colts but do have several Remington's, prefer 44 caliber although I have two 36'ers, and nothing in brass or will ever have. Nothing wrong with Remington's, just like the look and feel of the Colts more. As far as the OP mentioned caps, there is a world of difference between 10's and 11's. There is no such thing as a #10 nipple or a #11 nipple, ya gotta try what's available for the best result. I'm aware that some aftermarket nipple manufacturers advise that their nipples are geared for #11's. That may be what they used to design them with, but all of them I've tried a Remington #10 works even better. Try a Remington #11 on some of those nipples that state they are geared for a #11 cap and the fit will a bit sloppy in alot of cases.
Remington #10's IMO and of many others are the best as they have the longest skirt to fit down over the nipple for adherence before and after firing and the internal diameter of them fits tight over the vast majority of factory and after market nipples. CCI #11's or RWS 1075's are pretty much the same internally as Rem 10's but have shorter length skirts. Never have had problems with either. Stay away from CCI #10's as they are short skirted and have a smaller internal dimension. They will not seat fully on any nipples factory or aftermarket with out having to use like a wooden dowel to seat them and then sometimes its questionable and bothers me to do so. I tried them on just about every factory and aftermarket nipple available today. Still have almost 500 of them I bought at the time not 'educated' enough on the differences in currently marketed caps. There are some cap guns of small caliber like .31 that supposedly they will work on. Remington #11's are both short skirted and seem to fit sloppily on all the nipples I've tried them on. Well got long-winded but I tend to do that at times. Good day to all. CC