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Posted By: Jose Fernandez Steel inserts for an old Darne - 10/28/22 04:28 PM
Hello,
I will make a pair of inserts to use a very pitted 12 ga barrels from an old Darne shotgun.
The idea is to make a 12 to 20 ga tube about 1 foot long, to avoid the heavy pitted area in the barrels.
My question is, the steel that it is locally available are:

-1518 carbon steel or
-T-304 stainless steel.

Could you tell me what material is better for the purpose?

I will work the material in a lathe.

Thank you for your replies.

Best,

Jose
Posted By: skeettx Re: Steel inserts for an old Darne - 10/28/22 05:08 PM
https://www.ebay.com/itm/283147457067?hash=item41ece7522b:g:XfwAAOSwYxBaHraj&amdata=enc%3AAQAHAAAAoL85WC4noFCgoi8Jiaxp5%2FydFuTCILk5zl2KGix7dD7CAhKu9VWpU0Tzd%2FzE8GdNInBYGVMu5W1BJ%2FXxNBQlyKZ7UWz%2B74LUX4RePeV%2B3XbMFGRTcKZJ0RsCprXCXGg%2Fk3n%2FaliK1WJEMOoKKAH9%2F6EOiW4rSGL9pEIFD6e%2Ba1GN6qs6wRkeAsOAXRTaCSq28EB22EEnplGf1axPUtozZxA%3D%7Ctkp%3ABk9SR56ujvmDYQ

Copy and paste above

Briley Sidekick, easy

Mike
Posted By: Jose Fernandez Re: Steel inserts for an old Darne - 10/28/22 05:23 PM
Hello Skeettx,

Yes that is probaby the best solution... if I live in USA.
Belive it or not, those inserts are considered by law "firearms parts" so you can not import them and if you bring them with you from USA, you commited a crime!
The option to make my own inserts is the best to make usable a fantastic shotgun that, besides the damage inside the barrels, are in really nice condition.
So, I still need to know, what steel to use (I know 4140 is the forum recomendation, but I can not find them here).
Posted By: KY Jon Re: Steel inserts for an old Darne - 10/28/22 06:40 PM
Might be easier to find a pair of 20 ga single barrels and turn them down to make what you want. For that matter the 12/20 chamber inserts do well.
Posted By: mc Re: Steel inserts for an old Darne - 10/28/22 07:24 PM
Anytime you use old shotgun barrels you will have some problems getting them concentric I have used pump shotgun barrels to make sleeves some are very heavy but pretty concentric it might be easier to hone the barrels to find out how bad they are.
Posted By: Colonial Re: Steel inserts for an old Darne - 10/28/22 08:25 PM
If the tubes you make are well fitted with no (Minimum!) clearance, the 1518 would likely work.
Remember, they will be supported by the original barrel.
Past 10 inches, pressure is low.
I have made short (2 3/4) inch long) 16 to 20 adapters from similar, and lock-tited in place.
I have had no problem.
My advice worth what you paid!
Posted By: Jose Fernandez Re: Steel inserts for an old Darne - 10/28/22 08:34 PM
Thank you for your reply, DmColonial!
What I can purchase here is a "barra hueca" (hollow bar by the translator); it already has 16 mm inside diameter, that is a lousy 20 ga bore (0.630"), so the main lathe work is outside (easier).
Locally, 1518 steel is 8 times cheaper than T-304 stainless, so if you think it will work SAFETLY, I will use it.

Best,

Jose
Posted By: Der Ami Re: Steel inserts for an old Darne - 10/28/22 11:13 PM
The barrel should be concentric if you turn it between centers.
Mikr
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 10/29/22 12:05 AM
What do the barrel walls measure? Every Darne at my house, 3 at the moment, is over .050 wall. I’ve measured guns that had .020-.030 thicker walls, too. If the gun saw double or triple proof, when it was a new gun, you might not need to worry too much, if you feed it light hunting loads.

Let’s see a photo of the flats and the tubes where they enter the flats.

Best,
Ted
Posted By: mc Re: Steel inserts for an old Darne - 10/29/22 12:18 AM
Original barrels are interesting to turn on center
Posted By: keith Re: Steel inserts for an old Darne - 10/29/22 08:51 AM
1518 is a relatively low carbon manganese steel. Manganese steel is extremely tough and very impact and wear resistant. It is also very corrosion resistant. But depending upon the manganese content, it could be extremely difficult to cut or machine in a lathe, even with carbide tooling.

I had to drill some holes in manganese steel several years ago, and it was the toughest stuff I ever drilled. Good HSS drill bits were ruined almost immediately. I can't remember whether it was cobalt or titanium nitride coated bits that finally got through, but it was very difficult. It was also very hard to cut with abrasive cutting wheels. I thought it was stainless, but later found out it was manganese steel. I got it for free. It turned out to be not such a great bargain due to how hard it was to work.
Posted By: GMCS Re: Steel inserts for an old Darne - 10/29/22 09:10 AM
Are you first going to ream the chamber and barrels concentric with hand reamers and then make the tubes to fit the bores? you might as well make the chambers 2 3/4 if not already. Please post pictures of your project
Posted By: Der Ami Re: Steel inserts for an old Darne - 10/29/22 08:32 PM
mc, yes turning an original barrel between centers would be interesting if you don't have a bandsaw and grinder.
Mike
Posted By: skeettx Re: Steel inserts for an old Darne - 10/29/22 09:57 PM
Why do all that?

I used Lothar Walther adapters to convert a Remington 3200 barrel set
to 16 gauge

Using a set of these
https://www.gunbroker.com/item/952494023

[Linked Image from jpgbox.com]

[Linked Image from jpgbox.com]
Posted By: Parabola Re: Steel inserts for an old Darne - 10/30/22 09:59 AM
Do the extractors/ejectors still work with the Lothar Walther inserts?
Posted By: skeettx Re: Steel inserts for an old Darne - 10/30/22 12:49 PM
I cut a slot in the inserts,
welded up some 12 gauge extractors,
and refitted them to 16 gauge.
All now work as a normal 16 gauge
Posted By: AGS Re: Steel inserts for an old Darne - 10/30/22 04:27 PM
If you use any kind of inserts, trybefore buying. I have a set of Brily's (the fits all version). an older set of another brand, and chamber adapters of several brands. Only the old ones work in 2-1/2" chambers and they were custom ordered for the gun.

I think you should really consider honing/reaming the barrels. I am refurbishing an old R-11 16 ga right now. The bores were horrible looking. I lengthened the chambers so I could us inserts if I wanted. I used a long forcing cone reamer to helps remove some of the worst pitting. I then used an expanding reamer to remove about 0.015 from the bores (diameter). After honing and polishing the wall thicknesses were still thicker than the bulk of the doubles I shoot.

This is a common case of worrying about originality, when in actuality the serious pitting will detract more from value than a barrel opened up, clean and still with good wall thickness.

Do a lot of measurement before hand. It is hard to hone heavy pits out smoothy and reaming to size then honing is usually better. I have found that I was always surprised, however, how little removal can be needed to remove some horrible looking pits.
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 10/30/22 07:38 PM
Originally Posted by Jose Fernandez
Hello Skeettx,

Yes that is probaby the best solution... if I live in USA.
Belive it or not, those inserts are considered by law "firearms parts" so you can not import them and if you bring them with you from USA, you commited a crime!
The option to make my own inserts is the best to make usable a fantastic shotgun that, besides the damage inside the barrels, are in really nice condition.
So, I still need to know, what steel to use (I know 4140 is the forum recomendation, but I can not find them here).

The OP is in Mexico. He is honest, and law abiding, and as a direct result of that, he has been targeted by virulent leftist Mexican gun laws. Had he some street cred with one of the larger cartels, Eric Holder and Barrack would have personally seen that he had access to anything he wanted, but, that privilege will go to others. Too bad.

Suggesting he acquire a part to fix his gun is a no-no. He can’t. So, well intentioned that anyone who has posted on some nifty part that they can buy of eBay, or, wherever, is doing him exactly no good.

Make note of it. You ain’t in Kansa anymore, Toto. Americans always believe their gun laws are the only gun laws. Not so.

Guess I’d shoot for measurement and cleanup, which, if he is talking about producing a part on his own, he should be pretty close on equipment.

Good Luck, Jose’

Best,
Ted
Posted By: skeettx Re: Steel inserts for an old Darne - 10/30/22 10:05 PM
YES, but the Lothar Walther inserts are ONLY sold in Germany smile
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 10/30/22 11:35 PM
Originally Posted by skeettx
YES, but the Lothar Walther inserts are ONLY sold in Germany smile

Man, that’s handy.

Best,
Ted
Posted By: Jose Fernandez Re: Steel inserts for an old Darne - 10/31/22 03:08 PM
Hello everybody,

Thank you for your replies, I am sure all opinions and advice are with the best intentions.
It will be fantastic if I could use the shotguns "as is" without inserts.
It is a 12 ga and 65 mm. the barrels are really light and, I think, very thin also, but I do not have meassure equipment to know for sure.
For my eyes the pitting are horrendous; I saw "eroded craters" just ahead of the forcing cones.
I am not sure if I could take good pictures of the damage, but I will try (any advice?)
Also please tell me how can I post the photos (I do it in the past, but I do not remember how).

Best,

Jose
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 10/31/22 10:36 PM
Jose’
You can email photos to me, if you wish, and I will post them.

That said, from your description, it might be a good time to dismantle the breech of the old Darne, remove the strikers, and hang the gun on the wall as a gunroom decoration. I’ve never seen a blown up Darne, and it would be nice to keep it that way.

Best,
Ted
Posted By: Jose Fernandez Re: Steel inserts for an old Darne - 11/08/22 09:09 PM
Hello,

Finally I took some pictures of the Darne that I think are fine.
Ted Schefelbein, please send me your email address by private message and I will send you the pictures.

Best,

Jose
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 11/08/22 09:32 PM
Jose’,

Done.

Best,
Ted
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 11/09/22 12:18 AM
[Linked Image from i.ibb.co]
[Linked Image from i.ibb.co]
[Linked Image from i.ibb.co]
[Linked Image from i.ibb.co]
[Linked Image from i.ibb.co]
[Linked Image from i.ibb.co]
[Linked Image from i.ibb.co]

This, to me, is heartbreaking.

We are looking at a beautifully decorated P17 grade 12 gauge Darne.The bores were 18.2mm when the gun left the proof house, a snug, but, typical measurement for French 12 gauge bore at the point 9” from the breech. There is a lot to like on this gun.

But, just looking at those pits is stomach churning. My Father, career Marine, used to say if you wouldn’t drink the water in a foreign country, you shouldn’t load their ammunition either, and I would guess this gun has seen some corrosive ammunition in its time. A damn shame, really. It is hard to guess, but, those areas of missing metal would seem to easily be .020-.040” deep, and they are in a bad, no, the worst spot they could possibly be.

The Darne game is one I have played for a while, and, I have considered, on several occasions, orphaned barrel sets. They turn up infrequently enough to catch my interest when they do. If this gun were mine (it is not) I might try that avenue first, with the hope the barrels could be removed from the monobloc, and used in the existing monobloc. Because the OP is a Mexican citizen, I doubt that option is one he can pursue. Due to the severe rules he faces on repair or replacement parts, for not just this gun, but, any gun, I’m thinking the advice of removing the strikers, storing them under the butt plate, and hanging it on a wall, that I gave much earlier in this discussion, might be the best plan.

Good luck, Jose’.

Best,
Ted
Posted By: Tinker Re: Steel inserts for an old Darne - 11/13/22 02:24 PM
Something the fellow can buy on eBay is material

If he wants 4140 material, it's almost certain that it can be bought on eBay or some other online vendor
Posted By: coosa Re: Steel inserts for an old Darne - 11/14/22 05:14 PM
Originally Posted by Tinker
Something the fellow can buy on eBay is material

If he wants 4140 material, it's almost certain that it can be bought on eBay or some other online vendor


I understood Jose as saying that ordering anything from outside of Mexico would be illegal, so I don't think eBay is an option. Jose, is that correct? What about ordering something within Mexico? Is that a possibility?

I sure would like to help you, as would many others here. You have a nice shotgun, along with a lathe, and the ability to fix the gun if you can just find the right tubing. It seems to me that with the wealth of knowledge we have on this forum, we oughta be able to figure out a way to get a piece of tubing to you.

Jose, what can we do to help you turn this into a working gun again? Send me a PM if there is something I can do to help you and you don't want to make it public.
Posted By: keith Re: Steel inserts for an old Darne - 11/14/22 06:49 PM
Originally Posted by coosa
Originally Posted by Tinker
Something the fellow can buy on eBay is material

If he wants 4140 material, it's almost certain that it can be bought on eBay or some other online vendor


I understood Jose as saying that ordering anything from outside of Mexico would be illegal, so I don't think eBay is an option. Jose, is that correct? What about ordering something within Mexico? Is that a possibility?

I sure would like to help you, as would many others here. You have a nice shotgun, along with a lathe, and the ability to fix the gun if you can just find the right tubing. It seems to me that with the wealth of knowledge we have on this forum, we oughta be able to figure out a way to get a piece of tubing to you.

Yep, I find it hard to believe that a Mexican citizen is prohibited from importing a piece of 4140 or other appropriate alloy steel tubing. I think Jose was trying to say that it would be illegal for him to import gun parts such as sub-gauge chamber inserts. If I'm wrong, then it is pretty sad that any government would stop a law abiding citizen from importing steel tubing, when they essentially turn a blind eye, and permit tons of cocaine, heroin, fentanyl, and other narcotics to flow across our now unsecured Southern Border. Shame on our corrupt Democrat leaders for permitting it too.

I would also imagine that 4140 or another appropriate barrel tubing alloy would be available somewhere in Mexico. That or a pair of good used 16 or 20 gauge shotgun barrels to cut and machine to fit.

That is a nice looking shotgun. I would be hesitant to give up on it or relegate it to wall-hanger status just yet. One thing I have learned is that simply looking down a bore is not a good way to judge the severity of pitting. They typically look a lot deeper than they actually are. I myself have found a pretty good way to get a reasonably good measurement of the depth of barrel pitting. I also have an endoscope (bore scope). Cheap endoscopes and endoscope attachments for cell phones are available on Ebay and elsewhere.
Posted By: Jose Fernandez Re: Steel inserts for an old Darne - 11/15/22 06:21 PM
Hello gentlemen:

Thank you for your warm answers.
I can not import any gun parts to Mexico; that is for sure.
I am not sure if I can buy one meter of steel tube from outside vie Internet; probably need to pay taxes or perhaps I am not allowed to buy steel from outside the Country, I do not know.
Locally I obtain 1518 steel with a 16mm inner diameter and 32mm outer, so I can make the inserts with that material.
I also hardly want to use that Darne again, so I think the best (from safety matters) is to convert it to a 20 ga via steel inserts.
Your words and interest in the subjet are the best help for motivate me to do it, thank you!
I will comment here the advances (or failures) I will have with this project.

Best,

Jose
Posted By: Jose Fernandez Re: Steel inserts for an old Darne - 08/07/23 04:33 PM
Hello gentlemen:

I have some advances in my DARNE proyect: I bought 1517 steel tube and machine with a lathe a pair of 45 centimeters (about 18 inches) inserts.

Now I am giving the inserts the last adjustments and I hope I can permanently glue the inserts in the old and damaged barrels.
My question is, what kind of glue do you recomend to use?

I have in mind 2 types:

1.- 275 dymetylacrilate ester (I think you name it red Locktite) for permanent gluing of automotive parts and
2.- Industrial epoxy type glue (2 compound parts that mix together and starts to cure in about 30 minutes.

The tolerances that I obtain are really tight, in most parts there are about 001-002" between barrels and inserts, so I am concern about the use of option #2 because the glue is so thick.

I really want a permanent fixing of the inserts inside the barrels!

Any knowledge advise from you?

Best regards,

Jose
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 08/07/23 11:17 PM
Jose,
I would think silver solder would be a better choice. You would need to be careful, as the barrel tubes are held into the monobloc with silver solder, but, if worse came to worse, you would take it all apart, clean the solder joints in the tubes and resolder the whole thing back together. The gun could probably stand a rib relay anyway, at this junction in time.

I would be hesitant to use glue to hold the sub tubes into the bores of the old barrels.

Good luck.

Best,
Ted
Posted By: skeettx Re: Steel inserts for an old Darne - 08/08/23 03:39 AM
Graded approach
The liner can not exit the muzzle, they are only 18 inches long and fitted
to the bored out barrel.

The liner is held from exiting the rear of the barrels by the breech face

So try the Locktite and if the liners should move then go with the silver solder
That will require great caution and re-bluing

Mike
Posted By: BrentD, Prof Re: Steel inserts for an old Darne - 08/08/23 12:28 PM
Rifle liners are held in place with Locktite. Soldering is almost never done in the last couple of decades due to the improvement in adhesives. Shotgun liners should be even easier to glue in place.
Posted By: Ted Schefelbein Re: Steel inserts for an old Darne - 08/08/23 07:36 PM
Originally Posted by BrentD, Prof
Rifle liners are held in place with Locktite. Soldering is almost never done in the last couple of decades due to the improvement in adhesives. Shotgun liners should be even easier to glue in place.

You might want to read about how a good gunsmith does a similar repair operation. It would seem this repair was done fairly recently ( less than a couple decades ago).

https://vicknairgunsmithing.blogspot.com/2022/12/correcting-excess-headspace-in-parker.html


Best,
Ted
Posted By: BrentD, Prof Re: Steel inserts for an old Darne - 08/08/23 10:13 PM
Originally Posted by Ted Schefelbein
Originally Posted by BrentD, Prof
Rifle liners are held in place with Locktite. Soldering is almost never done in the last couple of decades due to the improvement in adhesives. Shotgun liners should be even easier to glue in place.

You might want to read about how a good gunsmith does a similar repair operation. It would seem this repair was done fairly recently ( less than a couple decades ago).

https://vicknairgunsmithing.blogspot.com/2022/12/correcting-excess-headspace-in-parker.html


Best,
Ted


I've no doubt it works, but it won't look or perform one bit better than what other really superb gunsmiths do.
Posted By: keith Re: Steel inserts for an old Darne - 08/08/23 10:42 PM
Ted, that Parker chamber repair by Dewey Vicknair was amazing. But I'm not surprised.

I think either solder or the correct adhesive should work if the fit of the sub-gauge tubes to the bore is close. I used a Loc-Tite retaining compound to replace the hardened valve seat in a lawn tractor engine, and even with that sort of heat, it never moved in roughly 15 years. I merely roughened the loose valve seat with a small carbide bit in a die grinder and did the same to the recess in the block. 18" long tubes have many times more contact area. And for that same reason, if Jose chose to go with solder, I'm sure plain old 60-40 tin lead solder would be more than strong enough. Plus there would be less risk of melting the solder joints in the monobloc.

I have no experience with the very low melting point Tin-Bismuth solder alloys, so can't comment.
Posted By: ClapperZapper Re: Steel inserts for an old Darne - 08/08/23 11:24 PM
He’s essentially making a chamber mate from scratch.
Why doesn’t someone with a machinist’s talent get out their mics and help the man out.

There’s no reason to reinvent the wheel here.

Just saying

Might be just the thing for the diy gunsmithing section.
Posted By: skeettx Re: Steel inserts for an old Darne - 08/09/23 01:54 AM
The old gauge 12 gauge chamber and pitted barrel bored out a bit for 18 inches
Then a THIN WALL insert is fabricated and placed in the barrel to give a new
20 gauge chamber, forcing cone and leade configurations.

https://chiappafirearms.com/product.php?id=565

The extractor must be modified to 20 gauge
Posted By: Jose Fernandez Re: Steel inserts for an old Darne - 08/10/23 02:53 PM
Thank you, as always, for your good advise!

Probably the "ortodox way" to fix the inserts is silver soldering, but I do not know a person that do the procedure nor I have the knowledge to do it myself, so I will try the "Locktite method"

I think I am still several weeks away of the "final product", buy I will continue to work in the project as times allow me.

Best regards,

Jose
Posted By: GLS Re: Steel inserts for an old Darne - 08/10/23 05:25 PM
A choke maker that has done work for me over the years before he had the .410 tap would sleeve chokes and secure them to the barrel with Loctite. I had one made up for a friend over 10 years ago and it still holds fast. Gil
Posted By: ithaca1 Re: Steel inserts for an old Darne - 08/11/23 11:17 AM
Why not make the inserts with an interference fit and press them in, as opposed to solder or adhesive?

Hope this helps.

Bill
Posted By: keith Re: Steel inserts for an old Darne - 08/11/23 06:30 PM
Originally Posted by ithaca1
Why not make the inserts with an interference fit and press them in, as opposed to solder or adhesive?

Hope this helps.

Bill

In my experience, many machinists have problems managing to bore or machine a correct interference fit on beefy things like shafts for bearing races, and pump, motor, or line shaft couplings that are quite thick and only a few inches deep. Oftentimes, the installation doesn't go well, even when the shaft is chilled with dry ice or liquid nitrogen, and the incorrectly bored coupling is heated to expand the I.D.

If things get stuck in the process, then delicate precision tools like sledge hammers, rosebud torches, or hydraulic pullers are used to help separate things.

Getting a correct interference fit on two relatively thin walled tubes that are 18 inches long, and successfully pressing them into the ends of 28 or 30 inch long shotgun barrels is a recipe for disaster, especially if the fit is only a little bit too tight. I'm not saying this method wouldn't be possible, but the difficulty and potential for problems illustrates why even shorter rifled bore liners for pistols are secured with solder or an adhesive.
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