Gunsmithing Question-oversize chamber

I bought a .22 barrel liner and installed it in the rifle. I did a trade with guy who had the special drill for the barrel liners from Brownells. I drilled a rifle for him and since he had the chamber reamer and head space gauge he chambered my rifle. I got the barrel back today and the chamber is about .002" over what the original chamber was. The original shot out chamber measured .228 and the new chamber is .230. The rifle seems to shoot OK but I have not yet installed the new sights and am not sure. The rifle is a Remington model 6 and is one of the earliest ones so it is about 100 years old, if that makes any difference. I assume that the rounds the rifle was designed for probably used black powder instead of smokeless, so maybe that is way the chamber is smaller than the new reamed one. However, I think it is too big and the dimensions I have found online agree with me. I do not want to remove the new liner and start over again and I cannot ask the guy who chambered it for me to buy me a new liner. So I am thinking about using electroless nickel plating to shrink the chamber. I could pretty easily devise and build a contraption that would slowly raise the barrel out of the plating solution so that the plating would taper to the full thickness, so that the plating would be full thickness for about the length of a long rifle case and then taper off where the chamber start to neck down. Or I could just stick the barrel in the solution to the proper depth and plate it the proper thickness and end up with an abrupt edge where the plating ends. This edge would be about .0015 high. Any thoughts? Thanks, Eric

Reply to
etpm
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I'd say get some sights on it and see how it shoots before you do anything . As long as it's not splitting cases and the case is sealing properly and not letting gas blow by it should be OK . I mean it's not like you're going to be reloading those cases ... My advice is worth what you paid , I'm not a gunsmith nor do I play one on TV ...

Reply to
Terry Coombs

If your barrel is a .22 rim fire the "head space" is determined by the case rim, not the forward end of the chamber. And, most .22 rim fire guns can be used with any one of the three lengths of .22 rim fire cartridges.

The SAAMI standards (available on line) list several chamber diameters for the .22 cartridge: .22 short chamber diameter .2291 .22 long .2307 .22 long rifle .2267 .22 long rifle - Sporting .2307 Unless otherwise noted all dia +.002

You might also want to read:

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Reply to
John B.

Thanks everyone for the replies. I guess I'll just run a bunch of rounds through the new barrel liner and see how well the rifle shoots. BTW, in my post I mentioned the age of the rifle in an effort to be thorough, not because the thing has any kind of value. I bought the rifle years ago just because it was interesting and because of the small size which makes it a perfect rifle for a child to learn on. Even though it was originally chambered for 22 long rifle and is so again I will mostly be shooting CB shorts or longs. I like those rounds because of how quiet they are. The action is described as a rolling block type but I have read that it is not actually a rolling block but sort of a falling block. I'm no type of an expert when it comes to firearms so that's part of the reason why I am concerned about the large chamber diameter. Right now the breech block does not contact the breech face in a parallel fashion because the breech face was so damaged I had to remove .010" in order to clean it up. I will need to move the barrel back .010" so that it will once again contact the breech block properly. Either that or move the breech block .010" forward. Because the barrel is held to the action by only one thumb screw I can see three ways to fix the problem.

1) Machine .010" from the barrel lug so it will slide forward. But then I will need to either add metal to the other side of the lug and machine it flat or shim it. If this is not done the barrel will slide back away from the breech block. 2) The reciever is a slab sided affair that is pinned together so I could press the pins out that hold it together and machine it similar to how the barrel lug would be machined and then build up with weld and machine back to size or shim in order to make sure the barrel cannot move from the new position. 3) Remove the rolling block which is retained by only one pin which it pivots around. Bore the hole in the rolling block oversize and move the location .010" in the proper direction at the same time. Then press in a bushing to bring the hole back to the proper diameter. I will probably use aluminum nickel bronze for the bushing because it would be perfect for this application. I don't think the breech block will provide much of a gas seal even if it contacts the breech face perfectly parallel. I think any movement of the shell case out of the barrel would tend to push the breech block away from the barrel at least a few thousandths of an inch and this would allow any gas that escapes past the shell O.D. to vent at the breech face. And this could maybe cause a burn if a child had a finger close to the breech. This is why I am concerned about the large chamber. Any thoughts? Thanks, Eric
Reply to
etpm

I've never seen a Remington Model 6 but I did own a Stevens "Little Scout" with the same sort of action - maybe the correct is swinging block rather than rolling :-)

If you milled the breech block and there is now a bit of a gap it might be easiest, depending on how the block is made, to simply silver solder a thin piece on the face of the block, drill for firing pin, etc., and then file or mill to fit. Providing that the face of the block is flat you would end up with a very thin silver line which wouldn't detract from the looks at all.

I would think that trying to re locate the barrel lug would be a lot of work.

Another method, that you mention, that depends a lot on what there is room for it, would be to bore the pivot pin hole in the receiver and the breech block a bit larger but in doing so move the center line of the hole to move the block forward to fit the barrel better. But, again, that is a pretty delicate project. We used to do it on .45 government automatics to tighten up some of the action but we had the jigs and tools to do it and we didn't bush the hole, just used an over size pin.

As for "gas shield" If the cartridge doesn't expand to seal the chamber, as it is supposed to do, you will get a blast of gas out of the action of nearly all firearms. Think of a revolver where the cartridges can actually rattle a bit between the rear of the cylinder and the face plate :-)

Reply to
John B.

If the "Little Scout" is the same as the Stevens Crackshot, it's a swinging block, in which the breechblock is retained by the lever action, either underlever or a side lever.

The Remington Model 6 is a true rolliing block. The breech block is retained by the hammer, with the locking action similar to the big old rolling blocks except that the hammer is configured a little differently.

Reply to
Ed Huntress

The easiest method is, for me, moving the hole. Since I am a machinist and in fact own a machine shop, the accurate repositioning of the pivot hole is easiest for me. Eric

Reply to
etpm

As much of a PIA it is I would move the barrel back using the lug.

This way you don't have to worry about modifying the rest of the action to operate. The Model 6 in .22 is falling block rifle not a true rolling block like the larger calibers. The hammer strikes a firing pin in the breech block. If you modify the block to move it forward you would need to alter the hammer and the blocks locking system to move it as well. If you don't it won't lock the breech solidly and will give you misfires due to the hammer not hitting the firing pin hard enough. .010 thou. doesn't sound like much but in a rim fire that is about 1/3 of the pin travel.

Reply to
Steve W.

Nah, Steve, it's a rolling block. First of all, a falling block has a breechblock that slides straight down in the receiver. A rolling block's breechblock has a pivot pin, and the hammer blocks the breechblock's rearward motion from recoil by sliding into battery against it. One curved surface (on the hammer) slides into battery with another curved surface (on the breechblock) as they each roll around their respective pins.

Here's a diagram of the action:

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In case this is an "Improved" model 6, here's that action:

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It's still a rolling block but the breechblock pin is closer to the bore axis, which puts almost all of the load on the breechblock pin and relieves the load on the hammer pin. Because there isn't much of a couple, the lip on the hammer that locks the breechblock is reduced in size.

Rolling blocks, like the sometimes-called "swinging black" Stevens Crackshot action. resolve the recoil load in a couple between two pins: the breechblock pin and the hammer pin, in the case of the rolling block. Falling blocks transmit the recoil load to the receiver through the flat back face of the breechblock.

Reply to
Ed Huntress

Greetings Steve, Looking at a cross section view of the action I see how the hammer has a convex arc that fits into a concave arc in the breech block. Moving the block pivot forward would put a gap in between these two arcs which would allow the breech block to move backwards if the shell case pushes on it when the rifle is fired. Thanks for the advice. This is why I posted the questions in the first place. I hope I would have discovered this relation ship of the two parts myself once I took the breech block out but maybe I wouldn't have. So your reply at the very least saved me a bunch of time. Cheers, Eric

Reply to
etpm

No the "Little Scout" and the Remington 6 had an "L" shaped breech block that pivoted under the barrel and when the hammer dropped a shoulder on the hammer fitted below the rear of the block and thus locking it up. I referred to it as a "L" block rather than a "Rolling" more as a matter of the shape. See Remington "Rolling Block" components at

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Remington Model 6 components at
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Little Scout components at
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Note the shape of the breech block and location of pivot pin in each action.

I suggest that the fact that the breech block is retained by the hammer is not the defining characteristic of the "rolling block". See

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Reply to
John B.

Yes, I would agree, if you are equipped to do it. Although I suggest that you might, if you are blueing or browning the action, want to make a test weld on some mild steel and than blue the "test piece" to see if the color of the blued weld matches the base piece. Sometimes it does... and sometimes it doesn't :-)

Reply to
John B.

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