[texcl2]

I'm looking at the Swede RB shotguns coming in right now and would love to get one for duck hunting here in north Dakota. My questions are, do these have choked barrels? My model 20's barrels are all heavily choked which is great for sharptails and waterfowl. Second, if I decide to get a gun with a poor bore and line the barrel down to the next gauge do you think it will handle regular target/bird loads if I chamber it to 70mm or will the action stretch? The pressure of the original 12.7x44 round was 11760 psi psi and Max pressure for a modern 12ga shell is 11400 psi so I assume it would be fine I'm only looking at commercial action guns. If lined it would make a great heavy duck gun but not much of an upland gun.

 

[kriggevaer]

Yes, they are choked, but I do not know the range of constrictions used for all the different model RB shotguns. I have used a choke gauge to measure two Husqvarna 12 ga and they were both a tight full choke. Whether or not an RB shotgun is going to be able to handle modern loads is going to depend on the year they were made and if the receiver isn't stretched already. The various models date from the 1870s to 1949 and if it was a later shotgun, later meaning 1920s-1940s period, It might be okay, but personally I would not be running loads generating contemporary pressures through one. I have seen rolling block shotguns with stretched frames. These guns probably dated to the early 1900s and both had non-Damascus barrels.
As far as lining the barrel I have no experience in that with rolling blocks.
Where are you seeing this RB shotguns coming in? They have been pretty scarce.

 

[Ken]

First, I am not a gunsmith however I have seen lots of these over the years and tend to be getting more conservative when using older guns than I was in the past.

All of these were designed to use 65mm shells, if it was mine I would use shotgun cartridges that developed the same amount of pressure (RST and others makes low pressure shells in both 2 1/2 and 2 3/4).

I have seen several that were converted to 32-40 using a heavy sleeve and bushed firing pins that seem to have held up OK, however I am not sure if this is really a safe conversion. You must remember that it is not only pressure but the amount of thrust you will have (the larger the case head the more this is of concern).

Instead of looking for a project (poor bore needing to be replaced/re-lined....these guns often also show lots of hard use/abuse) I was always looking for high condition guns, especially latter guns with duel extractors and a safety hammer.

Rollers (both military and commercial) can be a lot of fun to play with but I always remember the age, condition, and original design limitations.

 

[texcl2]

When did the hammer safety start showing up on the shotguns, I've heard it was later in production. I figure I'll use the same loads I use in my model 20s which are pretty low pressure but stout enough for grouse, pheasants ect... Is the rolling block action weaker than a model 20?

 

[Ken]

When did the hammer safety start showing up on the shotguns, I've heard it was later in production. ..... Correct, the hammer safety was found as standard on the latter guns, however I have seen early guns where the hammer was replaced with a latter safety version

I figure I'll use the same loads I use in my model 20s which are pretty low pressure but stout enough for grouse, pheasants ect... Is the rolling block action weaker than a model 20? .... Probably about the same strength as both were designed to use the same 65mm shells.