Good to know I aint the only one to pull this'n.On my f/s flint Hawken,affecionatly named BooBoo-when time came to drill trig plate for the tguard front stud,I had the 1/4 28 stuff on bench,somewhere my poor ol brain come up with 5/16-18.Yep,drilled that skudder for 5/16,then realized the stud on guard was 1/4 28.Went ahead and tapped it ,countersunk top and bottom of plate,screwed in a 5/16 bolt,peened over both ends,THEN drilled and tapped for 1/4-28.
Ol Boo boo has a few back ups,but still came out good for first build in 30 years.
Dave,yo be a'rite,bro.Dave