Big Bore 54Cal Roundball in-line

[52Bore]

After acquiring the GM54, I think it’s needs a big bore mate - 54 1:48 for Round Balls!
Found one on the Internet, 1” octagon 26” long.
Thinking along the lines of the big 12b.
Lots of work ahead.



last 3 photos are of the 12b build.

 

[Matthew323]

At 12 pounds it will weigh in right where a traditional Sam Hawken .54 caliber plains rifle would have, 10.5-12 pounds, depending on barrel length.

With a 1:48" twist you should be able to get decent accuracy with heavy powder charges if the depth of the rifling is sufficient to really grab onto the tight weave of a tightly-patched ball.

If you have 0.010", or deeper, rifling than you should be able to comfortably go over 100 grains equivalent of black powder for plus-100 yards accuracy with a good scope.

Who made the barrel, and how deep are the grooves?

 

[52Bore]

At 12 pounds it will weigh in right where a traditional Sam Hawken .54 caliber plains rifle would have, 10.5-12 pounds, depending on barrel length.

I don’t know what it will weight. My 12b weighs 8# and GM54 7#. This one when complete might be in the 8# range. I might taper the straight octagon slightly?
Unknown barrel maker or any details other than 54cal. But bore is like new, that was my only concern.
Thanks

 

[Confederate rifleman]

Irrc, 12b is 12 bore, not pounds. Right? The .54 will be a tad easier on the shoulder!

 

[rugerbh103]

Wish I had the skills. I have wanted a roundball shooting Knight for years.