Interesting question(s) & different ways of looking at them.

2 guns - similar calibre we'll say - the ctg. gun is pretty much restricted to how much powder the case will hold along with a bullet. The muzzleloader does not have that restriction and can be loaded with more powder - that's a given.

For instance - a .577 BPE is restricted to about 160gr. of powder with a 650gr. bullet. In a muzzleloader, there is a loss of pressure at the breech but could be loaded with an approriate sized bullet - same weight and 200gr. of powder which would increase it's performance over the BPE.

For instance, comparing a 16 bore BP rifle shooting round ball, the same situation happens. My 2.450" brass cases will hold 160gr. of 2F, a wad and round ball. I could easily shoot more powder than that in a muzzleloader - but why?

Most muzzle loaders of the day had much stronger breeches than a ctg. gun. The breech of the 1855 H Whall .75 ball and shot gun I borrowed for a shoot a few years back, had a damascus breech almost 1.4 across the flats, while an 1860 12 or 11 bore ctg. gun made of damascus has no where near the size and thus the 'apparent' wall strength of that muzzleloading gun was greater than a sypical breechloader of the same period - yet we will assume both are safe with whatever charge thet can shoot. The muzzleloader will 'admit' to more powder than the ctg. gun & thus would have more power - is it needed?

The deal about loose actions - loose actions must be repaired - generally no problem - on the other hand, being a solid gun so to speak, yes, muzzleloaders don't suffer from loose actions & generally have more power - but - they are a bit slower to load. My 14 bore, shot to shot took 8 seconds to load and shoot - ctg. guns are quicker and have all the powder necessary - but not the appeal of a similar muzzleloader - that opinion is biased

. Some ctg. guns can be loaed with an empty, primed case (not advisable - but they can), then upended, breech locked, hammer at 1/2 bent and loaded as a muzzleloader. Guys have done this with .45/70's and loaded them as it they were .45 3-1/4" by loading them from the muzzle - grooved lubricated or paper patched bullets. Paul Mathews gun smith did this very thing, and used thumb tacks as targets at 100 yards. Still, a properly made .45 cal. muzzleloading ctg. gun could be loaded with even more powder, but I wouldn't advise it, nor would I advise loading that way - but it was done.

The North American Indians were known to have loaded in this manner at times of having no fixed ammo using a Springfield where a single case was primed with modified percussion caps for primers. The Maynard breech loading rifle, made in the US of A in the 1860's, used fixed ctgs or .35 to .50 cal, but also had a primming case (lower part of a case) that could be pimed, inserted and the gun loaded as a muzzleloader. Any powder charge desired could be used or any weight of bullet desired, making it as powerful as any of the later to come, .50 BPE or .50 3-1/4" Sharps - of course, the 5 1/2 pound Maynard might kick a bit.

I don't know if this has anything to do with anything, but there it is.

Odd questions, Ben.