flame cutting on the cylinder

[oldgunclub]

I have two 629s, one with scope one without. Half inch from the front of the cylinder I am getting black marks from firing. I guess its the flame bouncing off the top strap hole, its alot worse with the scope model where the top strap screw does not go as deep. I shoot lite loads and it is starting to etch the cylinder. Is this normal or should I get a longer screw.

Thanks Sam

 

[murphydog]

Are you referring to 1/2" from the cylinder face, on the exterior of the cylinder?

 

[oldgunclub]

Yes. Does this only happen to stainless guns?

 

[colt_saa]

This happens on all S&W revolvers that are drilled and tapped for scope mounts if an improper length screw is used.

With the non D&T frames the forward tension screw for the rear sight was between the barrel and the top strap. The D&T frames use a much shorter rear sight base and the screw ends up being closer to the rear of the revolver and no longer protected by the barrel.

The screw MUST be flush with the top strap or it will cause that reflection of gasses and the carbon scoring that you are seeing on the outside of the cylinder. One of my Titanium cylinders developers little black circles over each charge hole.

The revolver that does not have a scope mount in can be sent to S&W for the proper screw.

The one that you added the scope mount to is your responsibility.

 

[oldgunclub]

Where can I buy the proper screw?

 

[jecsd1]

Ditto. My 686 is doing the same thing. Where can I get the correct screw.

 

[Les K.]

My Performance Center Stealth Hunter is doing the same thing. It's damaging the Melonite finish on the cylinder. I've emailed S & W customer support to request a longer screw and even told them that I don't care if it's longer than necessary as long as I can trim it shorter. I've also asked them to provide the specs of this screw (diameter and thread pitch) if they can't send me one as I've been searching for it at industrial supply stores which have much more inventory than regular hardware stores with no success. I can't find a diameter or thread pitch to match and it has an odd oval head profile.

If they respond, I'll post here what they say. I certainly don't want to send in the whole gun just to get that screw replaced.

 

[jfremder]

Ditto. My 686 is doing the same thing. Where can I get the correct screw.

Same issue here on my 686. Looking forward to a solution.

 

[clevelandgun]

I just put a new sight mount on my 629, I used 6-48 screws. Check at Midway and other places, they are available in a different lengths.

Mike
Slotted Oval .200 Diameter Head Screws 6-48 x 1/4 Blue Package of 10

 

[TSQUARED]

One cannot expect a used revolver to look as it has never been shot. All mechanichal devices wear with use - get used to it. The gun will probably outlast you.

 

[jecsd1]

One cannot expect a used revolver to look as it has never been shot. All mechanichal devices wear with use - get used to it. The gun will probably outlast you.

I don't expect it to look new. I was just wondering if this is a normal characteristic of the gun or if it was the result of an improper part being fitted.

 

[oldgunclub]

Flame cutting

I call Wigand Combat and told them I had a problem with flame cutting cylinder and they sent me 3 more screws which I had to file to make flush. I also ordered another site base for 8 3/8 629, I only fit the 1st hole next to the barrel with longer screw. I left the screw pruding a few thousands like the screw on the factory sites. One 629 6 " has a ultra dot, red dot. My new to me 629 8 3/8 i just put bushnell 3200 2 x 6, maybe I can post pictures later, with the screw pruding instead of leaving a cavity.

Thanks Sam

 

[jecsd1]

That would be helpful. Thanks.

 

[Les K.]

I just put a new sight mount on my 629, I used 6-48 screws. Check at Midway and other places, they are available in a different lengths.

Mike
Slotted Oval .200 Diameter Head Screws 6-48 x 1/4 Blue Package of 10

Thanks for that, and therein lies the problem. 6-48 is not a screw that is standard as far as I can find. I can find a 6-32 oval head and a 4-40 oval but the 6-48 might be difficult. I'll check out Midway some more.

 

[Drail]

My 696 exhibited what I think you're talking about when firing it without the sights leaving an open screw hole in the top strap but all I got were carbon spots. They came off with solvent. Did you actually have metal displaced on the cylinder or are you just calling it "flame cutting"? If it is more than just a carbon spot there is something seriously wrong.

 

[scooter123]

IMO the screw hole is getting a bit of undeserved blame for this. Lead will turn into vapor when exposed to the heat of combustion and it will then condense and deposit a residue when it contacts a cooler surface when the vapors have cooled to the correct temperature. Because these deposits are a result of condensation they can be rather stubborn and difficult to remove. On a stainless steel cylinder the easy answer is to use a lead away cleaning cloth on the deposits. On a blued, nickle, or titanium cylinder there probably isn't an easy solution, in that case plan on a long soak using a solution that is safe for the finish.

BTW, I've recently been shooting WWB in my 610 and paid the price for that choice today. It took a full 2 hours of work to clean off the filth that ammo left behind. In contrast I've been shooting Federal Champion in my 625 and with twice the rounds shot it only took me 20 minutes to get it looking new again. IMO what you are shooting plays a much larger factor in these issues than a short screw in the top strap.

 

[Les K.]

IMO the screw hole is getting a bit of undeserved blame for this. Lead will turn into vapor when exposed to the heat of combustion and it will then condense and deposit a residue when it contacts a cooler surface when the vapors have cooled to the correct temperature. Because these deposits are a result of condensation they can be rather stubborn and difficult to remove. On a stainless steel cylinder the easy answer is to use a lead away cleaning cloth on the deposits. On a blued, nickle, or titanium cylinder there probably isn't an easy solution, in that case plan on a long soak using a solution that is safe for the finish.

BTW, I've recently been shooting WWB in my 610 and paid the price for that choice today. It took a full 2 hours of work to clean off the filth that ammo left behind. In contrast I've been shooting Federal Champion in my 625 and with twice the rounds shot it only took me 20 minutes to get it looking new again. IMO what you are shooting plays a much larger factor in these issues than a short screw in the top strap.

The finish on my cylinder is not blue, stainless, or titanium. It is stainless treated by a process they call "Melonite" which I hear is the same or very similar as the "Tennifer" that is used by Glock. It is a beautiful black and otherwise durable finish but it must be sensitive to this kind of punishment. I tried the lead away cloth and that kind of worked for awhile, but it doesn't seem to do much of anything for it anymore. The marks line up exactly with the screw hole so I have no doubt that this is causing the blemish on the cylinder.

I'm going to be visiting a local gunsmith next week to see if I can obtain a longer 6-48 oval head screw quicker than if I wait for S & W or or order online. By the way, I'm not shooting factory ammo. It's 44 mag, 21 grains of 2400 using Winchester WLP primers under a Hornady 240 grain XTP. It seems to shoot pretty cleanly.

Thanks for the suggestion of at long soak though. I think that I'll try that but I'm hoping that removing the depression left by that short screw will greatly reduce or eliminate the marks, or at least make it really easy to clean them off.

 

[scooter123]

I'm not saying that the hole may not play a role in this, just that the cause lies with the ammo and the choice of bullet used. One sure way to reduce this is to use a jacketed bullet with an enclosed base such as Speer Lawman TMJ. Without any lead vaporization the resulting fouling is a lot easier to clean. BTW, I just love everything about the Speer Lawman line except for it's price, it's been exceptionally clean to shoot and in my 610 and 620 is the most accurate ammo I've ever used.

In regards to your melonite finish if it's truly melonite it's an extremely durable finish. I'd suggest a good soaking with M Pro 7 solvent and then the use of a hard plastic scraper to see if that will scrub it clean. You also may want to try a lead away cloth in combination with the M Pro 7, I've found this to be very effective in cleaning the carbon fouling from the face of my stainless cylinders.

 

[Les K.]

Hi Scooter,

They do say that it is truly Melonite used on the Performance Center Stealth Hunter and in my experience it has been extremely durable with the exception of the marking. Indeed, there is only the slightest indication of a turn ring after thousands of rounds fired. I've even heard that you can take a file to it and it will still be there because it actually case hardens and penetrates the surface of the stainless. Of course, I would never do this. It's a tough enough finish that the slightly abrasive lead away cloth, which is not recommended for blued finishes because it will wear it off, has absolutely no effect on the Melonite no matter how long and hard I rub. It does make it a little more shiny though.

I do use jacketed hollow points with the Hornady XTP. Only the front has some exposed lead, but it's in the cavity of the hollow point. I do however run the maximum recommended charge in the speer manual at 21 grains of 2400 so it's a pretty hot round. I'm sure that's not helping with the marking, but I love the big boom!

Thanks for the suggestion of the Pro M7. I have some and I'll try soaking the cylinder with that. By the way, as far as total metal jackets for the .44 Magnum, the only bullets that I've ever found that were fully copper enclosed were the plated offerings, and you can't push those very fast at all because the plating is too thin. Everything else that I've seen has been either plain or hard cast lead, jacketed hollow point, or jacketed flat point.

 

[Les K.]

My Performance Center Stealth Hunter is doing the same thing. It's damaging the Melonite finish on the cylinder. I've emailed S & W customer support to request a longer screw and even told them that I don't care if it's longer than necessary as long as I can trim it shorter. I've also asked them to provide the specs of this screw (diameter and thread pitch) if they can't send me one as I've been searching for it at industrial supply stores which have much more inventory than regular hardware stores with no success. I can't find a diameter or thread pitch to match and it has an odd oval head profile.

If they respond, I'll post here what they say. I certainly don't want to send in the whole gun just to get that screw replaced.

What I figured.....No response from S & W customer support whatsoever. I'll find a 6-48 oval head myself.