IME, it is mostly trial and error, Lloyd. The "formulas" for really nice patterns are few and far between. A pattern plate is really a good investment, if one is concerned about getting nice patterns out of one's gun(s). What works in one won't necessarily give the same results out of the next (seemingly) identical gun.

Ain't all this fun? grin

SRH


May God bless America and those who defend her.