Not detracting from your rifle as it si a very nice one. I do know the English rifles had lighter barrels than American rifles. Some claimed they liked to use Spanish steel, etc. At the time of the Revolution there have been comments on American metalurgy as one reason barrels may have been so heavy. Still if lighter rifles were made it is a possiblility. The story of Murphy's shots was that he went up into a tree to make the shots, likely for a better view. This would permit a rest such that it would in no way be likely that it was an offhand shot. Weight would not have mattered much. Mostly these storied tend to get exagerrated over the range the shots were made. Plunkett made the shots for the British, but most authorites do state it was far from 800 yards as some claim. The armies back then would get very close to each other without trading shots.
DP
There are a lot of factors here are some thoughts.
The Spanish steel went down in popularity when the English learned how to make steel just as good or better.
The reason the barrels got heavy hear compared to England (for one reason) is that a rifle made from a welded steel/iron mix, damascus if you will, is harder and will not require the same amount of freshing for a given level of shooting and if properly done will be stronger for a given wall thickness/bore size. Also the British landed gentry/royalty/peer was usually not in the same physical condition as some farmer in the US and were more accustomed to light fowlers.
Damascus is usually stronger that iron if done right and is strong enough to stand nitro proof. At least the British machine made stuff of the late 19th century was..
The iron, often old horseshoe nail "stubs" was also more purified, since it was remelted to bond the stubs together and form a homogeneous mass, than the iron generally obtainable in America or in the run of the mill import barrel. W. Greener was complaining of the poor quality of the export barrels being made in England circa 1832. W. Greener's "The Gun" details the use of "stubs". This is NOT W.W. Greener. Its HIS father. The later "The Gun and its Developement" is not the same book. Both are available for download on WWW but the W. Greener is harder to find W.W. keeps getting in the way. This said the BEST English damascus was pretty good barrel steel by the 1830s. But there was a great deal of steel that was far from "best". This is why its not really safe to shoot the run of the mill 2-5 dollar 1880s-90s BL shotgun with "wire twist" or damascus barrels even with black powder. When there are GOOD damascus barrels out there proofed for smokeless that are still in use at some level.
This said high quality iron properly welded will make a very strong barrel that is virtually "unbreakable". BUT the iron quality and the welding are CRITICAL. See the Springfield Civil War Rifle Musket. It has a skelpwelded barrel. These had and still have an awesome rep for strength.
AND the powder quality improved and the picket bullet was invented. The picket bullet often needs a lot more powder the shoot well than the RB thus the pressure increased even more. Chapman writes of using " ...2 inches in the bore..." of powder with a 38 caliber picket in the 1830s-40s.
The large bore rifled wall guns might have been able to hit someone at 800 with enough certainty to deny the area to an artillery battery etc. Shoulder fired RB arms, its a pretty remote possibilty even with the 20 bore Baker. Possible, but someone would have to be really unlucky to get hit.
There were sea change advancements in iron/steel making all through the 19th century. There was a quality leap circa 1859 and another after the Civil War. The differences, for example, between the 1874 Sharps receiver, 1860s steel/iron and the Sharps Borchardt of the late 1870s is marked. MUCH better material.
Cast steel is seen in many circa 1830s barrels. The problem with steel is that if its not properly alloyed it can make a pretty poor barrel. This could be a reason why the barrels got so heavy. GOOD iron makes a much better barrel than a steel made basically "by guess and by golly" with a really indeterminate alloy. All sorts of scary inclusions appeared in finished rifle barrels at least into the late 1890s. Look at some 1880-1890s Winchesters etc.
So we have steel and iron making that is by todays standards barely better than beating a meteorite with a rock, poor quality barrels both iron and damascus (massive fluctuations in quality of both) we have better powder and enlongated projectiles. Then the occasional burst gun to get folks attention. Yeah I can see why some Americans wanted a thicker barrel.
Dan
