Form Follows Function

[Pete G.]

Try to ride a horse with a long barrelled gun one time and it will become crystal clear to you why barrels were shortened.

[Chuck Burrows]

Try to ride a horse with a long barreled gun one time and it will become crystal clear to you why barrels were shortened.

Maybe so for some, but the fact is based on a bunch of original western fur trade orders that long barrels stayed popular well into the 1840's and as Taylor noted easterners rode horse as well - the long hunters used them extensively to pack their hides back over the Mtns and had longer barrels in general. And FWIW - I have done a lot of riding with barrels in the 36-42" length - it takes some getting used to and is probably one reason that slings were fairly commonly used - the works of A. J. Miller circa 1837, show a number of slung guns.
I haven't done the math on western orders but the average is pretty close to 42" on most of the orders I've seen - 38" being one of the shortest lengths ordered until post-1840. Even the rifles built by the Hawkens, whether half or full-stock didn't generally go to the 36" or shorter lengths until the 1840's and 1850's - the same time period that eastern rifles went to shorter barrels - as noted a time period when improvements in powder quality occurred as well as the "hotter" ignition of the percussion came into being. One thing that I believe may have also contributed to shorter and heavier barrels in the Far west is the incessant wind always something to contend with out here - a longer and lighter barrel makes more of "sail" in the wind than do the short, stout barrels.
As for a longer sight radius - yes to a point it may be an advantage, but on the other hand you also have a greater amount surface area for glare - the sun out here especially in the high country is bright and intense due to both elevation as well as less humidity.

[northmn]

Typical barrel configurations out of the Trade Rifle Sketchbook:

Deringer flint Indian rifle:  45"  1 3/32 breech 15/16 muzzle  1807-37
Deringer percussion rifle   42"  1 1/16 breech  7/8 muzzle     1830
Krider Indian rifle              42"   1 1/16 straight                      1840
J Henry English Pattern   >42    1 1/16 straight                      1825
J Henry Lancaster           >42    1  straight                              1822-45
J Henry Scroll guard        >40    1 1/16 straight                       1834-1855
Wheeler                            45    1 1/8 to 7/8                           1790-1820
Tryon Indian Rifle              35    1 3/16                                    1837-1855
Leman Percussion             32    1 1/16                                    1850 1870
J Henry Halfstock perc       34    1 1/8                                      1856-1870

As the majority of these rifles were listed between 45 and 54 with a 40 thrown in you can see by the barrel configurations a horse would have been handy to carry them.  Most were listed at around 9-11 pounds.  They got shorter as time went on and in percussion.  Flintlocks were said to be popular up to the 1840's.  These are the Western trade rifles, made for the fur trade and used by trappers, natives and whoever.

DP
 

[Roger Fisher]

I do not necessarily mean chunk guns in the terms as we think of them today but more the afternoon get together match rifle. 

DP

And shot from a rest.... I know of a a 'Johnston or Johnsten' 1 inch abt 39 in long straight (or nearly so) in what I  recall as a 32 or meebe a 36.  Weighs a ton and would be a real bummer for offhand.  So what was it's purpose other than to shoot from a rest (of some sort)    

[northmn]

I do not necessarily mean chunk guns in the terms as we think of them today but more the afternoon get together match rifle. 

DP

And shot from a rest.... I know of a a 'Johnston or Johnsten' 1 inch abt 39 in long straight (or nearly so) in what I  recall as a 32 or meebe a 36.  Weighs a ton and would be a real bummer for offhand.  So what was it's purpose other than to shoot from a rest (of some sort)    

How about the hockey stick drops on some of them.  Are they head up rest guns??


DP

[Acer Saccharum]

Hypothesis: As powder quality got better, barrels could be shortened.