Round barrels and keys

[Nordnecker]

My first build has oct/round barrel with keys. I've got the forestock pretty well shaped down. The keys aren't perfectly fit yet. I've got between 1/8" and 1/16" of wood either side of the barrel, coming to a rounded knife-edge at the barrel sides and the RR grove. Boy, it's like a 3 foot long egg shell. It just seems sooo fragile. The stock isn't fit as well as I had thought. It has a hollow sound when you tap on it. You can't see a space, but you can fit an ordinary piece of paper between the BBl and the stock in places. If I squeeze the wood, it will move, and it will flex/twist a little with the BBl in place.  I don't think the keys are going to stop this.
What should I do?

[galamb]

If you are not concerned about keeping it as HC as possible you can bed the barrel.

Using one of the various epoxy based bedding kits will do a couple of things.

First, it will take up any space/gaps between the barrel and the channel and second it will dramatically increase the strength of the forestock, particularly the web area which gets pretty well saturated all the way through.

Most of these kits are essentially a thermo-plastic based product (BPA) so in addition to the above benefits it also pretty much halts any chance of the wood sucking up water (so it remains more stable), won't rot or mildew and cleans up with a simple wipe from a damp cloth.

I also build/work on wooden boats as a hobby so have a lot of marine epoxy around. Every one of my barrel channels, lock/tang/trigger mortise and patchbox cut out gets a good dose of epoxy - all that it will soak up.
(just keep it away from anywhere you don't want to see it - it will not take stain so it will be visible. It can be tinted/coloured but that is a roll of the dice at best and it is always visible to some degree if you use it in the open)

HC/PC - not at all, but I expect most of the rifles will outlive me without need of repair at least from wood issues.

[smylee grouch]

If I was to glass bed the barrel, I would only do small sections at a time as the fit will be tight and breaking it loose the first time after your bedding compound cures might damage the fragile forend portion of the stock. Of course you have to make sure you have complete release agent coverage too.

[Artificer]

For many years, the only approved way ( by The International Muzzleloading Committee Rules for use in that competition) to repair a loose/worn/sloppy barrel fit in Original Stocks (to keep them legal in the Original Categories) was to use thin wood veneer that would be steam bent to shape and glued in with Hide Glue.  Then re-inlet the barrel. 

I was informed this was a HC/PC way to do it, but I never got their Rules Committee documentation for it.  I never did it myself, but I did see two different original Flintlock pistols where it had been used (in modern times) to tighten up the barrel fit. 

Though there are stronger (more recoil force resistant)  epoxy “glass bedding materials out there, I would probably use Brownells ACRAGLAS Gel to do the job, as you can dye it when you mix it to somewhat closely match the wood.  There is just enough “give” in it that it makes bedding Muzzleloading Barrels easier and to get the barrels out in the future and not bust the forearm.  I usually use Brownells ACRA-RELEASE as the Mold Release for these jobs as it helps get the barrel out in the future over tighter fitting Mold Release like Ram Mold Release 225.  You also need some kind of Non Air Hardening Clay to fill up holes or voids, before you bed the barrel.  In emergencies, I have used cheap modeling clay from toy stores, but the best stuff to use is Roma Plastina Art Clay in either the soft of medium texture.  (I like the medium, but others prefer the soft.)

The “trick” to using glass bedding on Muzzleloading Barrels is to get an Artist’s Pallet knife to spread it on the Mold Released barrel like one spreads frosting on cakes.  IOW, you put some downward pressure on the glass bedding and that prevents voids or air bubbles next to the barrel.  The super cheap pallet knives have too much spring in the blade, but the ones that cost about $ 10.00 have enough spring, but enough rigidity they work great.  The only time I spread the glass bedding into the stock is if there is a good sized hole or void in it. 

Oh, Smylee made a good point about only doing small sections at a time.  HOWEVER, you don’t want to keep spreading new glass over glass that is already hardened, when doing it that way.  That will leave “stepped surfaces” in the bedding and possibly ruin the bedding job.  IOW, leave some open space between the bedded surfaces when bedding the barrels that way. 

Gus

[Artificer]

OOps, forgot to mention for those who are not builders - To get the barrel out after bedding, use a ramrod that fits the bore well or a piece of brass rod that fits the bore well.  It should stick down the bore at least 6" if not a foot or more and leave it sticking out of the bore about 6".  Tap the rod on a solid bench with the barrel upwards and that will pull the barrel up loose from the bedding without marring the stock.

Gus

[Dphariss]

My first build has oct/round barrel with keys. I've got the forestock pretty well shaped down. The keys aren't perfectly fit yet. I've got between 1/8" and 1/16" of wood either side of the barrel, coming to a rounded knife-edge at the barrel sides and the RR grove. Boy, it's like a 3 foot long egg shell. It just seems sooo fragile. The stock isn't fit as well as I had thought. It has a hollow sound when you tap on it. You can't see a space, but you can fit an ordinary piece of paper between the BBl and the stock in places. If I squeeze the wood, it will move, and it will flex/twist a little with the BBl in place.  I don't think the keys are going to stop this.
What should I do?

Fowlers are supposed to be thin. Many rifles and almost all "modern" fowlers have too much wood in the forend. A friend of mine owned a Beck fowler years ago and said there was very little wood in the upper forend, REALLY thin.
You should be able to warp the stock to correct the fit of the upper forend. Unless the barrel has a crooked bore DO NOT BEND IT. If the keys are already in and the barrel is not seated well in the stock then glue a shim in the key channel and lower the key. This may require key escutcheons to cover the repair. If the keys are not fit simply clamp the barrel in the stock to warp the stock to fit barrel and drill the initial holes. The barrel is the strength, not the wood so conform the stock to the barrel. Glas-Bed with just add weight. Yeah it will be stronger and I have used it years back. But its last resort. If you do so use Acra-Glas Gel. Use a good floor wax for a release agent, two thin coats of all metal. DO NOT bed right at the key loops. When the stuff is set use a 1/2 steel rod from hardware store. Heat it to 800-1000 degrees and put it in the  the barrel so it heats where the bedding is. When the barrel is far too hot to touch dump the rod out and remove the barrel from the stock with a steel or wooden rod. The heat will soften or liquify the wax and it will come loose much easier. PS deburr the steel rod(s).

Dan

[smart dog]

Hi,
I am not sure you have a problem that needs solving.  Your keys and lugs should prevent twisting and the fact that the stock does not touch the barrel for all of its length is not really a problem except at the breech and ideally under the forearm where you grip it.  Other than that, the stock just hangs from the barrel neither providing support or affecting accuracy. If you really feel the need to fix the issue, Brownell's AcraGlas would be a good choice.  Gus (Artificer) supplied all the info you need but I would add one trick.  AcraGlas will release with mild heat. When pulling the barrel out after the epoxy sets, heat it carefully with a heat gun until it is just barely too hot to touch, and then follow Gus's advice for removal. 

dave

[Artificer]

Hi,
I am not sure you have a problem that needs solving.  Your keys and lugs should prevent twisting and the fact that the stock does not touch the barrel for all of its length is not really a problem except at the breech and ideally under the forearm where you grip it.  Other than that, the stock just hangs from the barrel neither providing support or affecting accuracy. If you really feel the need to fix the issue, Brownell's AcraGlas would be a good choice.  Gus (Artificer) supplied all the info you need but I would add one trick.  AcraGlas will release with mild heat. When pulling the barrel out after the epoxy sets, heat it carefully with a heat gun until it is just barely too hot to touch, and then follow Gus's advice for removal. 

dave

EXCELLENT advice and with a forestock as thin as a fowler, I could not agree more!!  Should have thought to mention it and thanks for adding it.

Gus