Converting a GM drop-in percussion to flint

[Walks with fire]

I have a .54 drop-in percussion 15/16" Green Mountain barrel that I would like to convert to flint and mount it as a switch barrel on a Lyman Deerstalker. I bought a breech plug from Track of the Wolf with the proper threads. The barrel has never been fired so I would think it would come off easier but getting the new one timed so the sights are up might be an issue. It looks like everything would line up ok but I wanted to ask around to see if anyone has done this conversion.

Is there anyone that knows someone who can do this conversion or has done it before? It would probably be cheaper than buying a barrel blank and all the parts and machining costs to make a new barrel.

Any advice???

 

[rushlake1]

Have you contacted Track of the wolf to see if they would?

Dennis McCandless in New Mexico did a couple for me...He has retired due to safety concerns around machinery and age..Great guy... did great work.
"Roundball" clued me into him.
We used Gm dropin barrels with TOW T/C flint plugs.
This is doable..ask around in a bigger circle.

 

[Hermit]

I just changed my last Perc. green Mt. 54 cal. barrel to flint, I had a flint plug that I fit to it, I had to heat the barrel to get the Perc. plug out, green Mt. put it in to stay, but it worked out ok, it is a real good barrel that I've had for several years.
Hermit

 

[galamb]

Yes, it's an easy process to have the flint plug timed in to match up.

It may require both work on the plug AND the barrel - not enough that other things (lugs etc) won't line up, it would be a tiny amount on the barrel.

If you are unfamiliar with the process, or don't feel you are able to do it yourself, just about any shop that works on black powder stuff can do it for you.

BUT this is not a simple unscrew the old plug, screw the new one in and off you go.

Track charges $25 to do it, Cains Outdoors used to charge $15 as a couple examples - plus whatever it costs you to get the barrel to them and back.

 

[necchi]

Track does offer the service for $25, plus the shipping you'd lay out both ways + the cost of the plug.
Or here's their instructions to do it yourself; http://www.trackofthewolf.com/Categories/PartDetail.aspx/1012/1/LABOR-BP

 

[MSW]

I've never worked on a Lyman (since I don't own one) but I recently did something similar on a T/C Renegade... it started as an accident: when I went to install a new nipple, the breech plug began to turn, so I took it all the way off and replaced it with a flint breech plug. Long story short; I now have a flint with a .50 and a .62 smooth, and a .54 percussion.

the tricky bit of doing a new breechplug onto an octagonal barrel which already has the underlugs cut, the sights on and so forth is that you need to have the bottom of the plug meet the barrel, the top of the plug meet the barrel, and you have to get the bottom flat to meet with the bottom of the barrel because the hooked breech must mate with the tang.

I was able to do this, but it required filing at both the plug and the barrel. Had I been able to keep the thought in my head long enough, I probably would have sent it to Track and plonked down my hard earned, overtaxed, God- entrusted dollars, but I got all brave and took out the files and then, once started, the project sort of took on a life of its own. It was a great deal trickier than I expected, but I was able to get everything to line up, and then I found to my dismay that the breechplug is just a wee bit larger than the barrel itself... well, the whole thing had to be drew- filed anyway, and now I have to figure out how to blue or brown or otherwise finish the metal...

:hmm: :hmm: :hmm:

use anti- seize compound ... this is important ... also, some folks use Teflon tape (not exactly HC/PC, but it is known to be effective). don't (of course) use both.

as regards the touch hole: I am partial to White Lightnin' flash hole liners. if you put one in the 'sunset position,' you'll get a nice fast ignition.

good luck with your project! let us know how it turns out and remember: we love pictures

:grin:

(the coolest tools are the ones you build for yourself)

 

[Walks with fire]

Well I called Track to see what the cost would be and I guess the plug used on the drop-in was 11/16 x 20 instead of the normal 5/8 x 18 on the barrel blanks. I guess TC supplied the plugs and I talked to GM about why they quit making them. They said they had trouble getting the plugs from TC so they quit doing it. I could get the right plug from Track with at least a 90 waiting period. The guy at Track also told me that he gets 100 calls per week for a GM drop-in percussion barrel. Said they get as much as 500 bucks for them on Ebay now.

I have decided not to attempt it and will get a barrel blank and go from there. I just can't see the benefit of taking apart a barrel that could sell for what it does. I have 2 of those drop-in barrels; one .58 and one .54. Here in PA the special season requires flint ignition. I will get a percussion lock at some point I think. I am pretty sure they would swap out on the TC stock.

I will try to do the blank myself so I will learn a bit as well.

Thanks to all who helped.

 

[MSW]

Walks with Fire, I didn't know that these guys were selling for that kind of money! Wow - market indicators and all ...

The T/C locks are interchangeable - you can swap a flint with a percussion in the same mortise.

Good luck with your project.

Make good smoke!

 

[necchi]

Yeah, but he's got an Investarms/Lyman Deerstalker.
The Investarms lock plate is just a little different then the T/C,, enough so that they will not just drop in to the others inlet.
You can't swap them without having to cut away a little in one area and have gaps in another area. I can't remember off hand but I think the plate screw is in a different location too.

In a pinch I'm sure you can make them work, but it's far from a clean job and "looks" like you have the wrong lock.
Investarms locks come up just as frequent as the T/C's so there's really no need to interchange the two.
There's 2 on flebay now compared to 3 T/C.
Ya just gotta keep watching to get a decent price.

 

[Walks with fire]

I also have a couple TC PA Hunter models that the drop-in barrel fits but I don't have a percussion lock for them; just flint. I wanted to put the drop-in on the Lyman because it has a pretty heavy butt stock and it balances real nice on there. Here in Pa; flint ignition is required in the special extra season and I want a longer barrel to fit my .54 flint Deerstalker stock to use as a switch barrel. I would like to have a longer barrel when hunting deer on stand and shorter one for the deer drives we do. The plug would need shaved a little on the end to fit the Lyman tang though.

I am leaning toward a 15/16 GM .54 barrel at 36" long at this point. I have the flint plug so I would need to cut the sight dovetails and under lug and install the under rib. I think it should balance ok even with the extra 4" over the 32" drop in. Browning the barrel shouldn't be a problem.

I would have at least 350 bucks in having someone build a drop-in so it's best for me to buy the blank and the rib; the rest of the parts I have already. Might just soldier on the rib; thimbles and under lug. Still thinking about it. I'm not getting any younger so I might as well have a little fun without a great deal of expense.

I don't think that a Lyman Great Plains barrel would fit the Deerstalker stock or I would do that.

 

[nhmoose]

Call Green Mountain ask for Jeff