Hi! I have an old Cape Gun (shotgun barrel on the left side, rifled barrel on the right side) made by Pieper, of Belgium, probably before the year 1900. While the left barrel is obviously 16 Gauge, I have so far been able to identify the cartridge for the rifled barrel. the closest I have been able to come is the .58 caliber Transformed Musket cartridge. This is not quite the correct one, as the rim diameter is smaller than the .58 T.M. the chamber dimensions are: Rim, 0.695" (17.68mm), case length 1.704" (43.28mm), base diameter 0.6235" (15.88mm). It is a straight-wall case and the neck diameter is 0.629" (15.35mm). Throat is 0.677" (16.52mm). Bore diameter is 0.5645" (14.34mm). Groove diameter is 0.551" to 0.570" (14.00mm - 14.478mm). I took the measurements many months ago and wrote them down, but do not recall why the measurements for the grooves are in a range of diameters. The measurements are, however, precise as I’m a machinist with instrumentation capable of 50/1,000,000ths of an inch accuracy. Bore and groove dimensions were taken off a .69 caliber soft lead ball driven through the barrel. Metric dimensions are calculated from the measurements taken in English units. Any better ideas of what it is? I’ve been unable to find any other cape gun that takes a .57 or .58 caliber bullet.
Is it possible to post some pictures of the rifle?(Follow the forum-instructions carefully and it will work fine.) And also from the proofmarks. As it is a Belgian rifle, caliber should have been stamped on the barrels.
Sounds like something similar to these, but in 28 gauge.
The top is a 24 bore by Chaudun (raised headstamp) and the lower a 20 bore by SFM Bruxelles. The case length of the 24 ga. here is 1.763 inches, and the 20 bore is 1.671".
I have three in 28 bore but the cases are brass and considerably shorter with from 1.39" to 1.5" c.l.
Two other 24 bore (not shown here) are both paper hulls with an about 1.3" c.l…
Also a 20 and a 24 bore but with about 2.8" brass cases.
All the rounds noted have lead bullets.
Interesting the barrel arraignment on your cape gun as I recall most British guns having the rifled barrel on the left, so you shot the “pot” game with the forward trigger right barrel & moved it back for dangerous game.
The variations in bore diameter may be because the rifle has an oval bore. I remember this was used in Lancaster 4 barrel pistols to enable the use of buckshot. I don’t know why they would do that to a combination gun when there is a perfectly good shotgun barrel next to the rifle barrel, so that feature would be pointless, but it may still be the case.
I don’t understand very well
You said the dimensions of the chamber are :
Rim diameter 0.695" (17.68mm)
Rim depth [color=#0000FF]What is it ???[/color]
Rear diameter 0.6235" (15.88mm)
Front diameter 0.629" (15.35mm)
Length 1.704" (43.28mm)
Throat is 0.677" (16.52mm). [color=#0000FF]What is that ??[/color]
And the dimensions of the bore are:
Bore diameter is 0.5645" (14.34mm).
Groove diameter is 0.551" to 0.570" (14.00mm - 14.478mm). [color=#0000FF] I don’t understand that.[/color]
[color=#0000FF]When you have a riffled barrel you have only 2 diameters : the bore diameter and the groove diameter
and the groove diameter is always bigger than the bore diameter[/color]
Forgive me if this is not what you mean by pointless.
A cape gun was used in Africa & named for the Cape of S. Africa. Where while out getting a bird for two or the pot you might well run into a buffalo who thought you might make a great mud pie. Armed with a shot gun you hadn’t a chance, other than to make him / her really mad.
So they fully rifled one barrel. Then along came Col. Fosbery (& others) who developed a barrel with the last two inches rifled.
So you could then shoot an accurate Paradox load in either or both barrels and also shoot a shot load in either or both barrels, & then Mr. Buff didn’t have such good odds as before when it came to making human mud pies & you could still get some meat for the pot in relative safety.
What I meant by pointless was that why would you need a rifle barrel that can fire shot when you have a shotgun barrel next to it?