Looking for a general feasibility check here. Would it be possible to convert a .410 single shot to 9.3x74R? I have an H&R single shot that isn't used much anymore. What if one were to cut off the existing shotgun barrel just forward of the hook, to preserve the current welded on lug and pivot pin relation, then counterbore/thread this stub to receive a matching barrel. You would need to do this fairly deeply, as the .410 chamber is just a little larger than the tapered 9.3x74, and this is the crux of the issue. The bonus is that the .410 and 9.3x74R rims are nearly identical in size, so you could keep the existing extractor, etc.

What kind of pressures are typical for the 9.3x74R? Would these exceed the frame ratings for this gun by too much? I know I can get a .410 barrel for my 45-70 handi-rifle receiver, so there should be no problems in getting a frame that is safe for the pressures involved with this cartridge, one way or another.

What kind of barrel and barrel stub diameters would you feel comfortable using? I want to say that the breech end of the current .410 barrel is fairly large for this chambering - something like 1.10+ inches - but I don't have the measurements handy. Is this enough meat to work with? What about soldering the barrel/stub assembly in addition to or instead of threading? How about making the first 1.5 or 2 inches from the breech a slip-fit (for soldering), while having a short threaded portion at the front of the stub to avoid any problems with deep threading and still control barrel attachment? This should be a pretty straightforward machining project for just the cost of a 9.3mm barrel blank, or am I missing something bigger?

If this would work, what kind of finished gun weight should I aim for? Is a 24" bbl adequate, or should I go for the 26" length? I can't think of any other rimmed cartridges in this class, and this might be a fun project to get into one.

One more try, BTT - just to see if anyone will bite....

I believe the shotgun and rifle receivers are different...the rifle's being stronger. H&R will not install a rifle barrel on a shotgun receiver, but WILL put a shotgun barrel on a rifle receiver.

Jon

That is true, so I was thinking of getting a .410 barrel for my rifle receiver and then modifying it. I should have rewritten my original post to make that clear.

No, I should have read your post more closely. Now I get it.
The same thing has occurred to me too and I don't see why it would'nt work. I don't think pressure would be a problem and a 26" barrel length would be perfect. But, if you have the skill and equipment for such a project would'nt it be eaiser to just machine a new lug (or use the one on the unwanted barrel) and have it TIG welded to a 9.3 blank?

Jon

captain,
i still have a savage 220 that i converted to 256 win mag. why, i guess because i could. i cut the original barrel off about 3.5 inches from the chamber end. bored it out to a larger straight hole. fit the 25 cal. barrel blank into the hole after they were both tinned. used force 44 solder to complete the job.chamber as usual and work out the extraction issues. one area to consider is bushing the firing pin hole to a smaller diameter to retard primer flow with the rifle pressure cartridge.
max