Hello Mustanger,
I am sure quite a few buffs were dropped with a levergun by the ocassional person wanting some meat fro the table. The serious commercial hunters stuck with the big single shots. However, I cannot even begain to tell you how many photos I have seen "from the day" that show a hunting outfit complete with a big single shot front and center and at least one levergun for camp defense or small game hunting.
Spencer's were used a bit early on. However even in sporting rifle guise they simply did not offer the power needed for a buff.
With the exception of the 1886 and Marlin 1881 leveractions which could handle a 500 grain bullet but came along way too late, most of the 45 and 50 cal. leveractions of the day were firing express type cartridges. (i.e. a light bullet 300 - 400 grain traveling as fast as BP could push it) The idea was to increase point blank range by increasing velocity and flattening the trajectory. They are devestating out to 100 - 150 yrds. However, they lack penetration for a tough buff.
Here is a good comparison:
A 45-70-550 paper patch leaves the muzzle at just over 1100 FPS but will punch clean through a buff at 100 yrds. (providing no bone is hit)
A 45-70-300 grease groove Express load leaves the muzzle at well over 1450 fps. It will get stuck somewhere inside the same buff. Yes modern jacketed bullets get stuck inside too but they kill diffrent then soft lead bullets they use shock and massive tissue damage. BP and soft lead uses penetration. A buff with a clean hole through both lungs wont go far. However, with only one lung holed he could go for a long, long, time with no apperant ill.
With that all said and done I would still like to have that Spencer sporting rifle along with a nice conversion revovler and of course the skining knives to complete the rig.