Given the number of hits this article has received, I will keep eye open for others likely to interest ASSRA folks. Svartkrutt has lots of nice info, often in well written Norwegian but more and more translated to English.

Pentz wrote on Sep 6^th, 2018 at 9:45pm:


12.7 Mike? Isn't the Swede Roller a 12.17? I see lots of references from people referring to a "12.7 Swede", but never seen one.

12,7X44R and 12,17X42R are almost identical and totally interchangeable. The 12,7X44R CF barrel on my Husqvarna kombi gun was initially marked 12,17X42R and later remarked to 12,7X44R. The 12,17X42R was the designation for original rimfire cartridge used in 1867 rollers. Most (almost all ?) of the originally manufacured Center Fire guns were marked 12.7X44R. All in keeping with older practice of sometime using bore diameter in designation, sometimes groove diameter.

For military matches the rimfire cartridges were required. Civillian matches allowed Center Fire cartridges, so, guess what? Folks that shot in both types of matches using their 1867 rollers had 2 breech blocks, one RF and one CF. The CF cartridges were widely reloaded.

Rebel wrote on Sep 7^th, 2018 at 2:00pm:


Is groove-to-groove in barrel of your rifle 0,515" or??

Pentz wrote on Sep 9^th, 2018 at 9:59pm:


Well, yes and no and both. 12,17X42R was original military designation for original rimfire verion. 12,7X44R was/is the original and still in use designation for the civilian CF version. So, ya got best of both worlds, but no rimfire block or rimfire cases.

With soft lead bullets, I would not bother with sizing die. 0,516" is likely just right for your rifle.  However, IF first cms of rifled bore is eroded, as it is in mine, you may find a bit larger bullet is useful. Mine gave really nice groups with a 0,520" pure lead bullet intended for a rifle used during USA Civil War.