Chamber adapter in old 16 gauge combi

[fisherman66]

I’m not sure if this fits best in the ‘smithy sub-forum, the shotgun one or the handloading one.

About a year ago I won an auction for an Merkel combination gun - 16 over 6.5x58R. It’s just hung out in the safe since then. The shotgun chamber is standard for that time - 2.5”. Not sure on the quality of the steel, but the gun is Nitro marked. I’m not sure if that pertains to both barrel/chambers.

Merkel was able to help age the gun, but most records were destroyed in the wars. The best the can give me is 1920-1922. It’s one of the oldest they have been called on to date.

It’s not easy to find short 16 gauge shells, and they are not inexpensive when found. I have a partial box of the rifle carts, but they are even harder to find.

I bought a 10” inch rifled 45acp chamber adapter so I can press her into service, but I’m starting to worry that the pressure exceeds the guns lock work.

I suspect most of the pressure radiates across the adapter’s chamber since the cartridge isn’t bottlenecked, but I’m worried about the press back toward the firing pin and the barring mechanism.

Does it make sense to start with low power rounds and work up if things seem okay? I’m not really sure what to look for in the case of over pressure except primer set back. Case cracking? I’d appreciate any relevant advice.

[tangolima]

It is a beautiful gun. The rifle chamber is 6.5x53mmR, or .256 mannlicher, correct?

I'd look into handloading for it myself, shot shell and rifle. Chamber adapter is just not the same.

The .45acp chamber adapter should hold the pistol round's lateral pressure. It has little or no bearing on the shot gun barrel. The pressure does try to open the action, and the lock work is the one that take the force. However if it can bear the rifle round, it would be ok for the pistol cartridge, although it is now fired through the over barrel. .45acp is a relatively low-pressure round. I think it should be fine if you don't plan to fire hot loads.

I probably would avoid .45acp rounds with small primer.

-TL

Sent from my SM-N960U using Tapatalk

[ammo.crafter]

Tangolimshot is on target with his advice. Reloading 16ga is the way to go as well as the rifle calibre.

If you will be shooting the SXS once in a while, a single stage shot shell reloader would be adequate for your needs.

[fisherman66]

https://www.amazon.com/photos/shared...Mss2Rr9b_kaWbl
https://www.amazon.com/photos/shared...0x2vQjW-BUtYsq

I wish I could get the other picts to work

I posted pictures here all the time years ago. For the life of me I can’t figure it out now, and when I get a link, the file size is too big. Arg…I’m turning into my father.

It’s a 1920’s Merkel, not a drilling - basic combination shotgun over rifle. 6.5x58R. Pretty low power rifle. I don’t feel the need to shot original carts right now if I can get this adapter in service. I have a Leupold 1-4 vari x II on it.

It’s a beautiful old world crafted piece with a horn trigger guard and schnable inlet. Pancake cheekpad and cartridge holder on the comb (weird place for it). The wood is stunning.

[Clemson]

RST has 2.5 inch shells that are correct for your chamber. As you say, they are not inexpensive, but how much are you going to shoot the old girl?
I have a couple of cases of 16's to use in my old Parker double.
rstshells.com

[fisherman66]

The insert performed well. I’m not going to be competing in any target shooting, but I could put food on the table inside 50 yards. I’ve only used range ammo. Perhaps I can find a load with an expanding bullet that will tighten my groups. I’m thrilled to put this 100 year old combination gun back into service.

[FITASC]

RST has 2.5 inch shells that are correct for your chamber. As you say, they are not inexpensive, but how much are you going to shoot the old girl?
I have a couple of cases of 16's to use in my old Parker double.
rstshells.com

Great company for those older short chambered guns from yesteryear

[Aguila Blanca]

What about having a chamber insert made for .410?

[Jim Watson]

Sure. Briley will even make a 28 ga full length tube for a 16. $700
For some reason, they do not list their short Sidekick tube for 16.

[4V50 Gary]

Beautiful, but is that a crack on the forearm?

[FITASC]

Beautiful, but is that a crack on the forearm?

Or is it a typical 3-piece forearm that seems to be popular with European, especially German and Austrian, long guns from days gone by

[FITASC]

ARG! Can't get a pic showing the 3 piece to post

[Jim Watson]

A 1920 gun will have no trouble with fresh shotshells of the right length.

If you have any 6.5x58R ammo, treasure it and plan on reloading.
Qual-Cart lists the brass but only when and if they get enough orders to bother with.

[fisherman66]

Or is it a typical 3-piece forearm that seems to be popular with European, especially German and Austrian, long guns from days gone by

I believe you are correct as the line is the same on both sides. A German combination specialist told me the gun was NOT likely refinished. I assumed it was because of the flat top checkering, but he said that was typical for these aged pieces.

If you have any 6.5x58R ammo, treasure it and plan on reloading.

I have 15-16 live rounds with 4-5 empty cases. I don’t plan on shooting them unless I can at a bare minimum find 100 or so cases. I had a ball shooting 45acp with it, but I need to notch my chamber insert so I can use a precision screwdriver to remove the case by hand. Using a fiberglass driveway marker to plunge it out muzzle side got old fast.

[fisherman66]

I notched the chamber this morning so I don’t have to run a driveway stale down the muzzle to punch out the brass. I can just get an eyeglasses screwdriver into the rim rebate. It will be interesting to see if it holds zero. I cleaned and lubed the shotgun barrel and the insert went in like butter. I hope the bullet’s inertia doesn’t spin the insert barrel. I think I might need to pull and dry the lube off the mating surfaces. My son gets leave before reporting to his new base in Japan in a couple weeks. I’m excited to take him out and show it off.

[tangolima]

Does the shotgun barrel have extractor/ ejector? It may be possible to modify it to work with 45acp. That would be cool.

I'd like the insert to "bite" into the shotgun barrel chamber. I probably would apply blue loctite. Any movement of the insert would make more sloppy with use.

-TL

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[fisherman66]

It does have an extractor, but I don’t have the skill or the wallet to do that job correctly. I’m happy to use a precision screwdriver to pop out the brass.

I think you’re right about the insert rotating with the bullet inertia. It uses o-rings to stay tight in the bore. I’ll shoot it this way and see is the notch rotates. If so I’ll try to come up with a way to add friction without modifying anything permanently.

[tangolima]

Blue loctite is pretty mild. Small amount of heat will undo it.

-TL

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[fisherman66]

I’ll have to think about how to apply it. There’s an o-ring on each end of the insert. I got to keep the chamber clean. I need a long needle tip to ensure it stays far enough from the chamber as I’m filling it and pushing it in.

[44 AMP]

If the .45 adaptor has a rim to replicate the 16ga rim, (some don't) then the shotgun extractor will extract the adaptor.

No way in hell it will reach the .45acp case, even if there is clearance to do so.

The rifle round is at least twice, (and possibly more) the pressure of the pistol round, and the action should be proof for that. I don't have data handy for that specific round but I would expect it to be in the 30,000 or possibly low 40,000psi range.

[4V50 Gary]

If the old extractor is intact and can be removed, it can be used as a pattern to make a new one out of 4140. Flat stock and if there's a hole, take all measurements off that.

Easiest way to do it is to photocopy the object, trim, glue onto steel of right thickness and then drill the hole and file to shape and fit. Then harden it for durability.

We had to make new parts for old guns in Repair Classes. One guy in the class two semesters ahead of me had to make a new safety for a C-96 Broomhandle.