Twist question for a TC 50 cal Buckeye special

[Edward]

I got this in a trade with a member here (never fired) till today and tried a lot of boolit/powder combos but still unsure of twist rate . I was told fast twist but
research on another site (Greybeard) this serial #BSS 00024 exact gun it says 1-48 ,my problem is education (high school) done .Most times no problem to determine twist rate ,BUT the rod goes 17.5 inch that"s it ! I get exactly 12 inch =/1/4 turn and then the final 5.5 inch it clears the barrel/not quite another 1/4 turn SO what do I have other than a lack of math skills . Did not shoot great with 490/495 RB /did okay with lubed Great Plains and best with S+W 501 sized to .499 w/ 2 wraps 9Lb group /Johnson 1942 made a custom 45 cal boolit that I shot fairly well (10 shot)while at the range.

[johnson1942]

ed, if it is 12 inches in a 1/4 turn it is a 1/48 twist. not to worry that can be made to shoot very very well. get a bullet that is around 7/8 of a inch long. find a cheap mold for the same and in 50 cal. cast in soft lead. get a reducing push through die from lee in .492 diam.size them to .492 diam. dry wrap either with number nine paper two wraps or single wrap with 18 pound freezer wrap paper. put down the bore on top of a 50 cal 60 thousands wad. it will shoot where you point every time. i sold a thompson 45 cal 1/48 twist barrel to koger a member of cast bullet. i shot a 250 grain .440 paperpatched bullet in that barrel and got 1 inch groups at 100 yards. you can do the same with the thompson 50 with the right bullet.

[OverMax]

With a grouping like that who cares what the twist is. I'd take that rifle deer hunting in a heart beat.