Question about shotguns
 

Back when meat shoots were shot at paper(at least where my dad and I went)I remember hearing the old timers talk about "sweating or pulling down"shotgun barrels for tighter patterns(I know we have screw in chokes,not the point).
What was the process?How was it done?They were not machinists,they were farmers.Call it my need to know:D.

RE: Question about shotguns
 

http://books.google.com/books?id=7Ab12fHr8y0C&pg=PA94&lpg=PA94&amp ;dq=sweating