.44RF rolling block, action strong enough to convert to CF?

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Ar180shooter

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So I recently came in to possession of a .44 Rimfire rolling block (no stock, action needs work to function), the bore is very dark/pitted, so I was thinking of having it bored out to a 50 cal of some sort and converting it to center fire. My question is, would the action be strong enough to handle a 500 S&W (with cast bullets and mild handloads), or should I stick to something more along the lines of a 50-70?
 
In general, I would definitely never chamber an old rolling block into a modern high-pressure round, even if you only plan to use mild handloads. 500 S&W runs 60,000 psi so it would instantly blow up and probably kill anyone who unknowingly slips a factory load in there. Besides, I doubt there is much 20,000 psi load data available for 500 S&W. I would stick with an old blackpowder cartridge with a nice low SAAMI pressure rating. Like the 50-70 you mentioned.

But I don't know anything about your action so at this point I wouldn't even recommend that. I have a Husqvarna rolling block action (buggered up 12.7x44 barrel and no stock) that is going to become a .45-70 and run with trapdoor-level loads.

Edit: I would also use a new production barrel blank which will give you a bigger safety margin over the old steel. And maybe new action pins but I've been told that the rolling block action doesn't rely on the pins for strength...somehow. I made new pins for mine, just the same.
 
No. Just no.

First person to put a factory round in it, even with a modern barrel, will likely wear the top half of the breech block somewhere behind their eye.

There is a series of very graphic images of a Swede rolling block that someone stuffed an assortment of modern ammo into until just that happened. Proving again, that common sense, isn't common.

Use a cartridge that is not liable to be loaded way beyond the reasonable limits the action was designed for. Even better, something even milder. The pins are not going to be the problem, if they fit at all well. The barrel is not going to be the problem either. Keeping the arse end of the cartridge from removing the top of the breech block, that is the problem with a rolling block action. It will be further compromised if the pins are loose, or if the breech block and hammer are not well fitted to each other allowing back pressure to start the whole lot moving rearward.

I have seen few enough questions of late that merit this response, but...Do you own a video camera that can be tripod mounted?
 
You should also drill gas escape holes in the sides of the breech block. If you pop a primer and the gas goes inside the block, it can push the hammer back with the firing pin (like a mini gas piston) and unlock the action. Also it's a good idea to use a smaller diameter firing pin by bushing the breech block but you'd end up doing that anyways when converting from rimfire. You can run higher pressure rounds if they are smaller diameter. The idea is to keep the hoop stress and bolt thrust equal to or lower than the original cartridge.
 
If you want to modify it to use a centerfire of some sort I'd go the other way. Drill out the bore and fit a liner suitable for use with something like .38Spl.

Looking up ".44 rimfire" suggests that this was the original Henry round. So it's not a weak round by any means. So going down to .38Spl would mean that the loads should be the same or even a bit less. But I certainly would not chamber it for a .357 Magnum given the likelihood of relatively brittle cast iron used for much of receiver.

A rolling block in .38spl would be a pretty nice and cheap to shoot plinker too.
 
I would have no problem setting it up for a modern cartridge but with the intention of only every running bp handloads. I also would pick a cartridge that I don't use in any of my other guns so nothing gets mixed up. Running a modern cartridge might cut your brass costs down nicely but I agree with the others in that if you sell it to a moron something bad could happen. I would also only run bp, not substitute or smokeless.
 
a j cave said:
No! My view, right or wrong, would be low pressure round. A 32-20 would be a fun round (1000-1600 CUP). A 50-70 also works at a low pressure (1400-1800 CUP)
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A .32-20 conversion would be nice too. And for all the same reasons given already.

I'd say no to the 50-70 though. It's a lot more powder and at least twice the bullet weight. So it can't help but have a lot more kick. And due to the increase in case head diameter it would put more of that pressure against the rolling block and pins. For something this old far better to go for something that is smaller and shoots lightly.
 
playkation said:
I would have no problem setting it up for a modern cartridge but with the intention of only every running bp handloads. I also would pick a cartridge that I don't use in any of my other guns so nothing gets mixed up. Running a modern cartridge might cut your brass costs down nicely but I agree with the others in that if you sell it to a moron something bad could happen. I would also only run bp, not substitute or smokeless.
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That's why chambering for something like .38Spl would be nice. SAMMI specs on .38Spl are light enough that it would be fine in the older action. Although if you were to go for something like the 32-20 that should be just fine too.
 
playkation said:
I would have no problem setting it up for a modern cartridge but with the intention of only every running bp handloads. I also would pick a cartridge that I don't use in any of my other guns so nothing gets mixed up. Running a modern cartridge might cut your brass costs down nicely but I agree with the others in that if you sell it to a moron something bad could happen. I would also only run bp, not substitute or smokeless.
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Remember it isn't about YOU or even SELLING the thing; it's decades down the road. If your kid or grandchild (or anyone for that matter) should drop a factory .357 mag round in there (or whatever) that YOU 65 years ago knew to handload down, well... it's your own personal ethical decision there.

BCRider said:
That's why chambering for something like .38Spl would be nice. SAMMI specs on .38Spl are light enough that it would be fine in the older action. Although if you were to go for something like the 32-20 that should be just fine too.
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Agreed that .38 special with a good barrel marking is fine for something like this; .32-20 would be neat. .44 -40 as someone else suggested ought to be a decent idea also, without seeing it in person. Backthrust is probably the key consideration although a brittle cast iron receiver would certainly make me think it through carefully.

Good luck OP it has a great potential to be fun rifle regardless.
 
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NorthCoastBigBore said:
Remember it isn't about YOU or even SELLING the thing; it's decades down the road. If your kid or grandchild (or anyone for that matter) should drop a factory .357 mag round in there (or whatever) that YOU 65 years ago knew to handload down, well... it's your own personal ethical decision there.



Agreed that .38 special with a good barrel marking is fine for something like this; .32-20 would be neat. .44 -40 as someone else suggested ought to be a decent idea also, without seeing it in person. Backthrust is probably the key consideration although a brittle cast iron receiver would certainly make me think it through carefully.

Good luck OP it has a great potential to be fun rifle regardless.
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Do we know that there is a brittle cast iron receiver?
We don't even know the make and model of firearm.
 
tiriaq said:
Do we know that there is a brittle cast iron receiver?
We don't even know the make and model of firearm.
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We don't know.

But we know that the action was never meant to handle 60Ksi loads, which the factory ammo for a .500 Smith and Wesson is rated at.

The "I'll only handload for it" line is crap. It's setting a potentially lethal trap for someone down the road. Far better to chamber it into a cartridge that is appropriate to the strength that the action was designed and expected to be able to handle.

The rifle is about a hundred years old already. We have no control over what happens to it when we are gone.

Consider that he 'best' of the Rolling block actions, when chambered in about the most modern rounds that they were in from the factory, 7mm Mauser, and 8x58R, used ammo that was far lower pressure than what went on to be used for the same chamberings in Bolt Action Rifles. This was covered in some depth on one of the other Forums with regard to loading for the Swede Rolling Blocks in 8x58R.

There were also some postings showing the rather gruesome aftermath of some guy stuffing random ammos in to a roller and shooting them, which resulted in his death, from the breech block entering his face near the eye socket and embedding itself there. Probably not an open casket at that funeral.
 
NorthCoastBigBore said:
Remember it isn't about YOU or even SELLING the thing; it's decades down the road. If your kid or grandchild (or anyone for that matter) should drop a factory .357 mag round in there (or whatever) that YOU 65 years ago knew to handload down, well... it's your own personal ethical decision there.

Kinda like selling a used car without having it governed to 50 kmh...after all some future doughhead might step on the gas in a school zone or something like that....

I'm currently working (cutting to octagon) on a 4140 CM 45-70 barrel for a # 1 Rem RB action and have complete confidence in doing that as I never intend to exceed BP pressures. As for a FP block coming unhooked, I have studied the RB for some time and altho Tiriac has seen photo's of this happening I never have. I have seen a # of photo's of RB that have split at the top ring causing. This allows the sidewalls to separate as well, allowing the pins to be turned loose at on end but every photo I have seen and altho they are disoriented, the blocks are still on the pins. Virtually every photo that I can remember seeing of a destroyed RB was a re-barreled BP # 1 action that had been converted to a modern high pressure smokeless powder chambering. Some people don't realize that there is a very big difference in metallurgy from the Swede's, Danes and milt #1 1/2 smokeless actions to the #1 BP action.



Agreed that .38 special with a good barrel marking is fine for something like this; .32-20 would be neat. .44 -40 as someone else suggested ought to be a decent idea also, without seeing it in person. Backthrust is probably the key consideration although a brittle cast iron receiver would certainly make me think it through carefully.

Good luck OP it has a great potential to be fun rifle regardless.
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...
 
fingers284 said:
Kinda like selling a used car without having it governed to 50 kmh...after all some future doughhead might step on the gas in a school zone or something like that....

I'm currently working (cutting to octagon) on a 4140 CM 45-70 barrel for a # 1 Rem RB action and have complete confidence in doing that as I never intend to exceed BP pressures. As for a FP block coming unhooked, I have studied the RB for some time and altho Tiriac has seen photo's of this happening I never have. I have seen a # of photo's of RB that have split at the top ring causing. This allows the sidewalls to separate as well, allowing the pins to be turned loose at on end but every photo I have seen and altho they are disoriented, the blocks are still on the pins. Virtually every photo that I can remember seeing of a destroyed RB was a re-barreled BP # 1 action that had been converted to a modern high pressure smokeless powder chambering. Some people don't realize that there is a very big difference in metallurgy from the Swede's, Danes and milt #1 1/2 smokeless actions to the #1 BP action.
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I've done my share of engine swaps with no concern; it's different scenario completely. My point (along the lines as has been stated already in this thread and many others) is quite very simply that if a guy knows a particular rifle is safe with the available factory loading then fill his boots. But IF the chambering that guy is considering has factory loads that are likely to blow up or cause some safety issue, and the reason he goes that route is for convenience of brass with him knowing to handload it down, well.... whether it's sold or its divided up in his estate or someone else's years later, those notes will be long gone. Stamping on the barrel is useful but not foolproof. .45/70 may well be a completely safe route here, the comment is more general; do your research and keep that in mind, that's all.

Maybe "X" or "Y" caliber is safe, great, no problem. The whole point is, it's wise not to chamber in something where factory loads are available that could cause an issue. That's it.
 
I have a rolling block in .32 rimfire which has a poor bore with a couple of bulges. I'd like to convert it to centerfire in a caliber suitable for deer hunting. Would this be a good idea?
 
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