Theoretical: Swedish 12,7x44R rolling block

[Dutchman]

My knowledge of paper patching is basic and book learned only.

The Swedish rolling block 12,7x44R uses a .512" to .515" bullet of about 350 grains. Up to 450 grains can be loaded but they're rather slow in that weight.

There are a few moulds that would work fine with the Lyman 330 gr .512" being the first but not only. There's a Lee custom 350 gr .515" and 350 gr .518" for the Smith carbine but I can't ever seem to find one for sale.

Lots of bullets in the .500" range for the various new superduty handgun cartridges like the .500 S&W.

The logical question is: can bullets of this type be paper patched and used successfully in the rolling block? For a .512" groove diameter what is the optimal bullet diameter for paper patching?

Just gathering intell on this at the moment. Thanks!

Dutch

[jonk]

.513" would be good if you have slugged it at .512.

You might be getting into a triple wrap but if you had a .500 bullet that might work just fine.

[45 2.1]

Dutch-
The patched boolit needs to touch the throat and lands snugly, no jump allowed. You need the patched diameter to fill the throat, that is providing the throat and chamber allow that. The prepatched boolit size depends somewhat upon the paper thickness you use. You need to slug the throat and tell us what its diameter is and what the inside diameter of a fired case is.

[pdawg_shooter]

I load various .451 and .452 pistol bullets in my 45-70 and 458 Win for small game and plinking. I found that 2 wraps of 16# printer paper works fine. As ling as the bare bullet fits the bore diameter +.001/.0015 and you can load them long enough to engrave the rifling accuracy will be good.

[Dutchman]

Well, I see this is going to take a bit more on my part.

The 1867 rolling block is all apart at the moment being "re-habbed" in a modest way. I have to mill a dovetail for a new front sight blade and then blue or brown the barrel and then put it all back together before I can shoot it again.

I've debated whether to keep it as 12,7x44R or thread the barrel stub for a pistol caliber re-barreling. Don't know yet. The 12,7x44R put 4 rounds into 1" at 50 yds so its not a bad rifle.

mucho thanko

Dutch