Home Workshop Barrel Rifling

Interesting, relatively low tech, barrel rifling.
https://www.youtube.com/watch?v=J3pDlKxou6Y

It gets worse! This fulla is makes his own 4-groove rifling button, but in quite a clever way using square tool steel.

https://m.youtube.com/watch?v=quYfN4LfT84

To get the rifling groove-to-groove measurements from a given size square steel you need to revisit your school trigonometry, SOH CAH TOA, or go to an [URL="https://www.omnicalculator.com/math/square-diagonal"online calculator of the diagonal of a square[/URL]

@Cordite please get rid of the fly on the bottom of your post, I almost smacked the laptop onto the floor

:redbullsmiley:

Or you could make a button from an Allen key, thd calculator for hexagin duagonals is here:

https://www.omnicalculator.com/math/hexagon

Such a button would need case hardening, but a BP barrel itself can be out of mild steel.

You could also hammer forge around a hard mandrel ;-)

Or use seam-welded galv pipe..