Hi Tim - just my thoughts, but I do think they were made, just not nearly as many as brass mounted guns, based on what has survived. There are a few that could fall into that period, such as the Old Holston Gun, and have seen others, but there is just no way of definitively dating them. I keep hoping though and I think someday we will find an example.
I remember passing on a very early iron mounted smoothbore a few years ago - and I know some of the folks on this thread saw it at Friendship as well. A long round thin barrel that looked restocked from an early fowler, a walnut stock with the forend replaced, a wrap over iron buttplate ala Chuck Edwards style, a nicely made but plain iron rifle style guard that looked a little too plain to be European, and American longrifle architecture with a cheekpiece, etc. And a big early style Germanic lock that looked to be about 1750-60s era. Front and rear sights as I recall. I did not know for sure what I was looking at - a plain German gun? Or another one of those American "maybe" pre-Rev iron mounted guns? Just hard to say. Sure wish I could get another look at that gun now....
The surviving iron mounted guns seem to mostly correlate with the production of iron in the southern Appalchians from a timing standpoint - you really see them beginning to turn up in appreciable numbers by the 1790s, more even from a decade later, and by the time you reach 1820-30 there were lots of them. Of course, logic would also dictate that the survival rates of any guns, iron or brass, decrease the farther back you go as well. So whether the increase in number of iron mounts from the post 1790 period is directly attributable to the availability of locally made iron, or just attrition making fewer of them available form the farther you go back in that period we don't know. They were making iron in other places even earlier, over near the coast, but we don't see the iron mounted rifles becoming popular in those other regions.
My thoughts are that the higher number of them turning up in the southern Appalachians/backcountry post-1790 was that it grew out of necessity and turned into a style preference, due to (1) the relative isolation of the frontier and (2) the later production of iron. Iron was what was available there, perhaps beginning with reforging out old parts or tools to make gun mounts, or maybe just more effcient if you were making relatively few guns, and later developed into more of a regional style preference as the local iron production started up in the southern backcountry. Whereas folks close to the coast would have more ready access to brass. I might be totally wrong though.
So if you want to use an iron mounted gun for pre-1775, I have no problem accepting it as plausible, for example - someone settled in what is now East Tennessee in the late 1760s-early 1770s. Heck, when it boils down to it, the number of surviving rifles of any kind for which we know an absolute date is a pretty small proportion. I would keep the style of the mounts close to the brass mounts of the period though, and simplify them and everything on the gun a bit. This just based on rare instances from later pieces where we get to see brass and iron examples by the same gunsmith.
Guy
