Greetings my Dear nativeshootist
The ASM, IAB, and other "cheap sharps" are really a crapshoot and one needs to be a psychotic
Determined amature gunsmith, like myself, to actually be happy with it.
Did I mention "cheap" ? The guts re quite rough and soft, and need a lot of work. The usual IAB trigger pull is worse than an issue musket, usually more than ten plus pounds. The ones with good triggers have been worked on, and it is important to pull the guts and make sure it has not been worked "too much" or has a negative angle on the search. The block often has junk inside all the intricate areas that needs to be cleaned, filed, or stoned. And the surfaces that should be hard, usually aren't.
But if one is persistent and willing to work over a pugs ear, it may eventually be satisfying!
I actually have a rough frame casting, a commercial pedersoli breechblock and guts and a barrel and am planning on building one up from scratch... I will see if it comes out better and sooner than my .54 IAB sharps... It will probably drag on for years, tho ......
Best advice? Save up for at least a Pedersoli ( ~ $1650 ) or Uberti or better, a C Sharps or Shiloh
Hope this helps
Prof Marvel