Ok, Let's just explain twist first, we got 1-28,1-32,1-48,1-60,1-72 and lot's of others in between right?
A 1-28 might be easiest to explain,.
1-28 means the "rifling"(aka;lands and gooves) of the bore will make "one"(1) full revlution in 28". If you could follow one of the grooves from the bottom of a 28" barrel all the way to the top, it would turn 360 degrees,a full circle.! :-) No more,no less.
K?,now let's try a 30" barrel with a 1-60 " twist". The twist it has will only move 1/2 way around,(180 degrees) while traveling that whole 30 inches of the barrel, follow?
To determine an un-known twist (close anyways) you need four simple things,
masking tape,
a pen or pencil,
a tape measure or ruler,
and a darn tight patch on a brush or jag for your rod.
Put yer brush/jag on the rod "tight" so it won't slip, push it down too the bottom of the barrel. Pull the rod up a bit and wrap some tape around it so you can make a clean "visable" mark on it whare it meets the muzzle while on the bottom.
Make another mark on the tape whare the top sight is,,,,,,
The idea is to "pull" the rod till the mark you made buy the sight makes 1/4 revolution and stop! After that it's all math :? geometery too!
If your rod mark too muzzle is 7",then it's 1-28, if it 8" then it's 1-32,if it's 12" then 1-48
Fast twists are a bit easier,,you can usually get a 1/2 twist with the rod, then measure, I got an old .45 thats stil open for debate,,1-60 or 1-66?? depends on the light,and/or the apple pie.
