doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Burst Barrel Repair--Sleeving & Other Options

Ref. my previous thread Burst Barrel ...and the said gun, and Greg Tag's reply..



..I have been offered the following repair at quite cheap price,

Ribs will be removed.
Damaged barrel (left) will be cut just at start of rupture.
A piece of barrel from some wasted gun with matching inner dia and suitable length will be welded with sawn off barrel.
Ribs will be soldered.
Barrels will be reblued.

What do you guys say..

I have yet to get the cost of sleeving from another gunsmith.

Could someone elaborate the procedure of sleeving as it is done in good old England.

Thanks

It's done the same way except the barrel is cut off just in front of the chamber and the chamber is reamed out. Cheap prices are not always a good thing. Make sure that the person knows what they are doing. I have never heard of anyone sleeving a barrel in the middle. I would insist that it be done near the chamber end. Its your hand that you have to be worried about.

Saad,
Are you in the U.S.? If so, I'd recommend that you only let someone qualified to sleeve a barrel do the work. That is, someone that has past experience and references.

Sleeving involves cutting the barrel off at a point just ahead of the chamber. Usually around 3" or so from the breach. The remaining chamber is bored oversize to allow for a predetermined wall thickness of the new barrel to have after fitting in the oversize chamber. The face of the remaining chamber must be machined perfectly square with the bored out chamber. Then a new barrel is turned to fit in the old bored out chamber. The new barrel should be restruck (filing and polishing of the barrel to control its profile). Then the new barrel is soldered, brazed, or welded in place. The traditional method is soldering the new barrel into the old chamber. Then, additional filing, blending of the profile of the assembly is done along with polishing and solder reassembly of the spacers to regulate the point of impact, assembly of the ribs and forend lug, cleanup of the soldering, more polishing and reblueing.

If it sounds like a lot of skilled work, you're right. If it doesn't sound like it requires much skill, I didn't explain it well enough to do it justice.

Saad, Hi.
Where are you?
This sawing the bbl off just before the rupture & welding on a length cut from another waste bbl sounds a bit iffy to me by your description.
Sleeving is basically cutting of the bbls just ahead of the chambers..about 4" or so ,boring out the short chambers/bores,
then turning down some tubes for a 4" stepdown that is seated into the newly bored chambers.
I'm sure I'll get some flack for my description.
Your way, seems like hes gonna try to weld two bits of bbl together with a circular weld around the bore....that doesn't sound like fine gun repair to me.
Perhaps I'm miss understanding.
If you go to the Gunshop home page...find John Foster UK in the advitizers drop box...he shows how he sleeves..& hes good at it .
cheers
Franc

Cutting the barrel, near the rupture will leave you with a butt joint that will be welded between two thin barrel sections. Quick, easy, but not a very good repair. Do not take the lowest bidder on this repair. Only the best repair possible should be done. The second failure might not be so luck as the first.

Proper sleeving involves boring out the chamber area, turning a barrel down to fit into the bored out chamber section and then welding both the chamber face and the joint between the barrel and chamber mono-block. Hence you are welding much thicker metal, in two places, and have the combined strength of both layers of metal. The difference is one area is repaired in .030 wall material and the other in .080 wall material. I want the repair in the strongest area possible.

What you describe is one of the least desirable repair. You will have a repaired joint, in thin metal, right at the area of the last failure. Not my hand, but that is one gun that I would never trust.

I'll go a bit further than Franc. The guy sounds like a barrel butcher with little knowledge of how to do it correctly. I wouldn't let this guy do the work. Nor would I want to stand in the same county when you shoot it. Your safety is at stake here, along with others that may be around you when you shoot the gun. Either get the job done correctly or set the gun aside. Another accident is not worth it.

I once owned a Miroku 20 gauge that had a cut off barrel section reattached by some method at the 11" point from the breech. It was a fairly neat looking repair, so a friend and I went out to test fire. The gun took a little bit of a tumble while it was unsurely leaned against a tree (as I remember, may have been against the car bumper). When I picked the gun up, the barrels fell off, yes, fell off. This is a true story that resulted in many pleasant days playing with an absolutely illegal 11" Miroku 20 gauge. I finally sold it (legally I hope) to a Class 3 manufacturer who procured a tax stamp and resold it.

Thanks for advice. I am aware that the sleeving process is different then what I mentioned. That is why, my topic subject "..Sleeving & Other Options"

@Chuck
I am in Pakistan. Your explanation in quite good and I can undertsand the amount of skill required for this job.

@Franc Otte

You got it right..sounds same to me, therefore I asked for opinions.

I took the gun to two gunsmiths in my city, one is the best and the other is just ok. Both offered the same repair which I have mentioned.

Both said that they have repaired many guns in this manner and the guns perform fine after this repair. The best guy showed me an OU repaired same way. A 6-7 inch piece at muzzle end of lower barrel was welded in same manner and joint was not visible from outside.

Both guys understand, what the proper sleeving is but cant do that because of un-availability of new barrel tubes and probably lack of expertise in barrel striking, regulating etc.

The gunsmith to whom I plan to meet is in another city and is basically a gun maker. He can sleeve barrels but to confirm his method with the standard process I have drawn steps of sleeving in following picture as I understand it from all above posts. Kindly confirm if am right?

Also mentioned what should be the critical measurements of minimum wall thickness at certain points.

I made & installed an approx 6" extension on a mod 97 Win pump once for co-worker. The original bbl had been cut off,don't recall exact length, but we made it to 30". I was able to put this bbl in a lathe & turn down about half the thickness for a bit & bored the extension to fit over it. I then silver soldered it on. On a double of course one could not do the work on a lathe, but not to say it could not be done by some other method. The important point will I think be how much bbl wall you have to work with.

Here is the drawing

That's correct Saad. They used to solder it in, now some weld it.

What is brazing?

And which type of welding is performed? In layman terms I know of two types of welding, one is electric welding using a welding rod and welding unit, the other is by using a gas torch and thin metal rod (steel, brass, etc).

Saad,
Brazing is typically a term used to describe using a nonferrous metal such as bronze or high silver content alloy for bonding two pieces of metal together, much like soldering only higher temperatures are needed. The term brazing also indicates the bonding metal is a lower temperature than the primary metal parts, unlike welding. "Brazing" that I'm familiar with has included bonding of steels, titanium, and aluminum.

http://www.key-to-metals.com/Article36.htm

Thanks Chuck!

Could you please further elaborate that how the chamber is bored out (steps 2 & 3 in drawing). I mean what tools are used.

What should be the minimum wall thickness of the turned down barrel at chamber area (setps 5 & 6 in drawing)?

Another stab at an explanation of the process:

"Sleeved bbls - An economical method of bringing new life to a damaged pair of barrels, regardless of their original method of jointing. The ribs are removed. The barrels are cut off 3" - 4" from the breech end and discarded. The bores of the remaining breech-end are reamed out oversize. New tubes are fitted down into the original breech section and filed down to fit flush. The original ribs are then replaced.

Sleeving is considerably less expensive than building a completely new set of barrels. Much of the time required to build a set of barrels is concentrated in the fitting of the breech end to the receiver; this work is salvaged through sleeving. Sleeving can be recognized by a pair of circumferential lines around the barrels a few inches from the breech; the more invisible, the finer the job. A sleeved gun should always be identified as such amongst the proof marks, and if done in England must be properly reproofed."

Saad,
when I bored the chambers, I cut the barrels at about 8" from the breach, then simply turned a piece of steel bar (mandrel) in the lathe to fit the bore, TIG tack welded the bar in one of the barrels, put the bar back in the lathe, indicated (trued) in the breach end of the chamber and bored just over 3" deep to the desired diameter, removed the bar and barrel from the lathe, cut the tack welds, repeat the process on the second barrel, cut the barrels to just over 3" with a saw, turned another bar about 2 3/4" long that the newly bored oversize barrels would fit over tightly, put the barrels on the bar with the forward end of the barrel where you can face off it squarely to the bore. Repeat on the other barrel.

It's extremely important that the forward face of the barrels be perfectly square to the bores. It's also extremely important that the bored out chambers follow the original line of the bore. So, I didn't use reamers for any of the work but rather indicated in and bored with single point tools.

Thanks Chuck.

So, traditionally reamers are used for this purpose?

Saad,
I don't know what is "traditionally" used since the one that I did was the one and only. Professional gunsmiths with English training like Mr. SDH and others may have more direct experience traditional methods and likely have done it much more than I have. As a former machinist, I can tell you that a reamer will tend to follow a hole axis, where a part that you've spent time indicating in and want the axis of the new hole to follow that axis, will be best done by singlepoint boring.

Chuck,

The problem is that, I see in your method it works with both barrels cut. Whereas, I am looking for a solution to sleeve one barrel only, the other one will remain intact during the process.

Do you consider it is possible to machine it using lathe with second barrel still intact?

It is possible to sleeve a single barrel on a double, my uncle has a SKB 100 with the left barrel sleeved. This would be possible on a lathe with the proper tooling and set up and the ribs removed. A special cutter may need to be made. I would think a set up such as is commonly used for opening chokes(different cutter of course) to square cut off tube. As for opening the old chamber, a reamer will work fine if you take light cutts, adjustable reamers work great for this. Good luck,
Steve