Shooting with high cylinder gap

Status
Not open for further replies.
F

Firewall

Member
Joined
Dec 30, 2007
Messages
51
I received a S&W 19 has a gift a few years ago and as I started to learn more about revolvers I came to realize it had about .005in of end shake. I fixed the end shake using the rings from Brownells but now the problem is that my cylinder gap is around .014. I dont plan on leaving it this way, but since I don't shoot this one a lot getting the problem fixed hasn't been real high on my list.

Tomorrow I'm taking someone to the gun range for the first time. Usually when I do this I let someone shoot a .22 for most of the trip and then move them up to a light .38 load before we leave. Unfortunately my collection has dwindled to the point that this is the only gun I have available for that task. Would there be any harm in shooting some (less than 50) .38 target loads through a gun with this much gap?

Thanks,
Matthew
 
No harm unless you stick your hand up there at the side of the cylinder.

That is the problem with taking up endshake that way, you increase the b-c gap. Endshake is usually not the result of wear at the cylinder arbor; it is almost always the result of wear (or tampering) at the ratchet and has to be corrected by replacing the extractor, not shimming the arbor. (Endshake can also be the result of actual stretching of the frame due to extensive use of heavy loads, but that is for practical purposes irreparable.)

Jim
 
Mr. Keenan, correcting endshake does not increase B/C gap - the gap was already excessive. When the revolver is fired and long before the bullet exits the barrel, the cylinder is pressed hard to the rear and it is stopped either from the ratchet or, if the last is too worn, from the cartridge rims - the gap is at its largest possible size. But you know that. I am curious - why did you say that correcting endshake does increase B/C gap?

Boris
 
Mizar said:
...Mr. Keenan, correcting endshake does not increase B/C gap - the gap was already excessive... I am curious - why did you say that correcting endshake does increase B/C gap?
Click to expand...

I'm not Jim, but I don't think that's what he was suggesting. Rather that by installing the shims in the cylinder to bear on the end of the yoke will force the cylinder to the rear, correcting the endshake, but also fixing the cylinder to the extreme rear of the previous range of movement, thereby rendering the cylinder/barrel gap fixed at its widest gap. This vice work on the ratchet (which is much more difficult).

His experience is different from mine in that I've never seen a ratchet that's been tampered with in a manner to increase endshake and, by default, cylinder barrel gap. I suppose that the ratched could have peened, but that would indicate that the headspace was long out of the box. My experience using the shims has resulted in only one gun that had less than acceptible headspace after installation, but many that had too much cylinder/barrel gap, which suggests to me that the end of the yoke was short (for whatever reason) and/or that gap was too wide from the factory, and/or the frame may have stretched to some degree.

Disclaimer - I'm not a factory trained S&W revolver smith, so there's much that I'm not privy to.
 
Last edited:
I know that, BBBBill. But Mr. Keenan clearly stated - "That is the problem with taking up endshake that way, you increase the b-c gap." The large gap is already there to began with. Fixing it to the widest measure does not change anything - it does not matter if one sees the gap or not - when the gun is fired the gap will stretch to .014" before the bullet exits the barrel. With or without excessive endshake.

Boris
 
Mizar, you may not be aware of it, but Jim Keenan has probably repaired more Smith & Wesson revolvers than you've ever seen pictures of. I know my way around a Smith pretty well, and I've done some work on'em...but if I ever get into one that's over my head and it's kickin' knots on me...you can bet the farm that it'll be Keenan's brain I'll be pickin'.

When the revolver is fired and long before the bullet exits the barrel, the cylinder is pressed hard to the rear and it is stopped either from the ratchet or, if the last is too worn, from the cartridge rims
Click to expand...

Nope. Sorry. When the bullet is driven through the chamber throats, it drags the cylinder forward. If they're oversized, it doesn't do much of anything, though with very high pressures, the expanded cases may grip the chamber wall and drag it rearward...but not violently. If the cylinder stayed with the cases all the way, there would be no need to worry about headspace, other than to insure that there's enough to allow free cylinder rotation.
 
Tuner, I know about Mr. Keenan's reputation and I always enjoy his posts. That is why I asked him to explain to me his statement.

Concerning your post I have a question - if the cylinder isn't pressed hard to the rear then how, on a well worn revolver with excessive endshake, we see a peened ratchet and it's indentations on the frame every time? The cylinder is moving quite violently front and back in the frame. Mr. Keenan said the following - "Endshake is usually not the result of wear at the cylinder arbor; it is almost always the result of wear (or tampering) at the ratchet..." From where does this wear on the ratchet comes then?

Best,
Boris
 
Well, speaking for myself, (and I thank you folks for the kind words), Boris is correct. I should have said that shimming will force the cylinder to the rear and fix the b-c gap at its maximum. As to ratchet wear, I have seen quite a few ratchets worn enough to cause an excess b-c gap. That can also be caused by people trying to correct the lockup by peening the ratchet because they read that the cylinder must lock up "like a bank vault", something that is hard to get on an S&W revolver.

Jim
 
Fix any cylinder end-shake..then have the barrel set back to correct cylinder gap.
 
Sorry for just now getting back to the thread, I missed the email notification about replies.

I ended up taking it with me and letting her (my mother inlaw) shoot about 2 cylinders full of some light .38 though it. The flames out the side were noticeably larger but that was the only issue. (On a side note, she wants one now. Probably a snubbie model 10)

Now to just get the barrel screwed in further. Is this something most gunsmiths can handle or something I should leave exclusively to S&W? I'm on a tight budget so saving on shipping costs would be great.

Also, does anyone know much about that process? I would think some material would have to be removed from the barrel to screw it in further. I would think the nickel plated finish will complicate this issue?
 
Status
Not open for further replies.
Back
Top