Marman underhammer build

[Rolfkt]

I've been building a Marman underhammer based on blueprints by Runastava. The Locks are made from scratch from sheet metal and bar Stock. Hawken triggergard from TOTW.




The barrel is a straigth octagon blank from Burton, that I've hand rifled. It's 31"long, Caliber 0.54 and 1" across the flats. I'm thinking of turning the barrel octagon to round. Would this be safe or would the walls be to thin?





Plan to Stock the rifle in Cherry, use a hawken butt plate, pewter nose cap and silver wire inlay.

Best regards
Rolf

 

[Swamp Rat]

It's coming along, I like what I see. Does it have a half cock position on it? On turning the barrel round I wouldn't do it, Not because of safety issue (idk) but for the ease of dove tailing or screws used for sights, lugs, and thimbles.

 

[44-henry]

It really depends on how small you plan on turning it. If you reduced it down to .936 you would (depending on actual bore size) have around .200 of metal left on the sides. That is more than you have on a 45 caliber 13/16" octagon barrel and they are regarded as safe. I have even heard of a few 50 caliber 3/4" barrels, though I would not personally want to build from one of those. Also keep in mind you are turning it forward of the breech, you are still leaving plenty of metal at the back end and that is where I would want to keep it.

 

[Rolfkt]

It's a simple Lock to make. No half Cock position.
The head of the hammer has to be milled out to get it to lay horisontal in the fired postion.

Best regards
Rolf

 

[BillinOregon]

Fascinating.

 

[MSW]

great machining ... wish I had your skill!

 

[Rolfkt]

The Cherry blank turned out to be to soft so I use a hard Maple blank I got from Jim Kibler. Still got away to go.

Best regards
Rolf