First, get yourself a copy of....

by Sarge , Central Misery, Monday, August 19, 2013, 01:32 (4058 days ago) @ rob
edited by Sarge, Monday, August 19, 2013, 01:39

"The Colt .45 Automatic: A Shop Manual Volume 1" by Jerry Kuhnhausen and read it cover to cover about five times. Then find yourself a used, beater Rock Island or Auto Ordnance and go to town. Either of those guns will be on or close to the blueprint in all the areas that matter.

FWIW, barrel fitting begins with an in-spec slide stop crosspin hole and a 'match' slide stop with a crosspin that is a consistent 0.200" all the way across. Simply installing one of those will often show an improvement in accuracy. I have squared bottom lugs with a 3/8 rod wrapped in 320 silicon carbide paper... not kosher, but it works for me. I smoke them with a candle to find any high spots and stop when engagement is consistent across both.