Grenadier1758 said:
I have my theory of why there were so many swamped barrels and no straight barrels during early manufacturing of gun barrels.
When a skelp of iron is forge welded around a mandrel, the iron is up set and excess metal is pushed toward the breech or muzzle as the barrel is formed. Once the barrel is forge welded and draw filed to final shape after straightening, reaming and rifling a swamped barrel profile is what happens. The swamping can be noticeable or barely visible.
It is interesting that when the large lathes and mills were in operation and the technology to make the deep bored holes in barrels, very few barrels were swamped. Most were tapered or straight.
I don't think that it was an artifact of forging, if that is what you are saying. The folks forging barrels up at Williamsburg have to deliberately taper out the skelp to replicate original profiles, I believe, and there is too much of a pattern to how profiles change over time to let me believe that it was just a matter of how the iron moved under the hammer. Your theory might work for those very subtle late barrels, but not for early barrels with more pronounced swamps.
However, you might be on to something as far as variations in profile go. A spot that requires a bit of extra attention in the weld might thin out a bit more than the surrounding spots, and influence the shape of the final product. (I don't any forge-welding yet, so don't know how exactly that would look like in practice, but that seems plausible). Also, as anyone that has had to file-finish a hand-forged piece of metal knows, there is always that one little divot that is a bit deeper than the rest and just doesn't want to file out. If you are filing out a straight profile, getting rid of that one spot requires filing the whole barrel down until it disappears. With a swamped barrel, you can just adjust the profile a bit - shift the waist forward or backwards, make that concave taper from the breech to the waist a bit more concave, reduce the flare a bit at the muzzle, etc., - allowing you to file or grind away the bad spot without having to reduce the whole barrel to match. So while I think that swamped barrels were always intended to be swamped, the variation in profiles very well be due in part to the accidents of forging.
Yes, Virginia, it is entirely logical to believe that manufacturing swamped barrels might actually be easier than straight, when using period techniques, so the notion that there were a bunch of poor men's rifles with straight barrels that just got used up doesn't really make much sense, does it?
As for why they liked swamped barrels, they never wrote that down, so we are left to guess. As my first response to 40 Flint was meant to indicate, they seem to have liked a bit of muzzle presence in their rifles (at least Americans did. Can't speak to European piece), so they weren't trying to make a rifle that handled like a shotgun. Swamped barrels do allow you to have a good stout breech without making the gun unmanagable, however. Also, it fits the aesthetics of the age - I'm hard pressed to think of designs of anything from prior to the Industrial Revolution that features parallel lines. Finally, as I've pointed out before, the handling of a gun (or other weapon) isn't just a matter of where the gun balances, but how the weight is distributed - the flare at the muzzle adds to the moment of inertia at that point, and, at least in theory, should make for a steadier gun than one with the same balance point but the metal located closer to the actual balance point. How significant that actually is, particularly with some originals with very slightly flared muzzles, is debatable, though.
