Just Another GPR Build

[Birddog6]

Dan,

If I remember correctly, take the needlenose vice grips, put on the spring guide rod right in front of the shoe of the tumbler, push left on the rod to collapse the spring, lift the rod out of the shoe. It is a pretty stout spring.
Then you can disassemble the lock.

Keith Lisle

 

[Flash Pan Dan]

Thanks Keith, that work well. Does anyone have any ideas how I might fix this odd grinding error from the factory.

Is this a matter draw filing to make even?

 

[Birddog6]

It is normal for them, as they were mass produced & not machined together.

Yes, just draw file it out. If you want the Lyman name & etc. off, take a 1/8 dia punch & put the barrel on the back of a vice & start punching the lettering, not hard, just start working it easily & allot of the lettering will mush back together. Then when you have about all of it, draw file that as well & the Lyman name will disappear. Look a the adjacent flats & dray file the adjacent edges to keep the flat edges even. When you brown it you won't be able to tell the dif.

Keith Lisle

 

[Goldhunter]

It is normal for them, as they were mass produced & not machined together.

Yes, just draw file it out. If you want the Lyman name & etc. off, take a 1/8 dia punch & put the barrel on the back of a vice & start punching the lettering, not hard, just start working it easily & allot of the lettering will mush back together. Then when you have about all of it, draw file that as well & the Lyman name will disappear. Look a the adjacent flats & dray file the adjacent edges to keep the flat edges even. When you brown it you won't be able to tell the dif.

Keith Lisle

Also, when you draw file the tang and barrel together try this: Super glue them together.

The glue will minimize movement of the two pieces so they will match better. A little heat will separate them when done.

 

[Zonie]

I suppose that would add some extra insurance but my breech plugs are tightened with at least 10 ft/lbs of torque.

When they are tight, they aren't going anywhere from the light pressure created by a draw filing operation.

Speaking of breech plug tightening torque I know there are some who believe this item should really be torqued down hard.

To them I will mention the fact that threads only have so much strength in them.
If they are over tightened they will use this strength to force the end of the breech plug and the shoulder against the immovable shoulder/end of the barrel leaving very little strength to cope with the high pressure of the burning powder.

If the threads are overstressed by a combination of torquing and powder gas pressure they can shear off resulting in the breech plug being blown out.

 

[Flash Pan Dan]

I started to lightly peen the lettering on the barrel and noticed that it wasn’t doing much good. So I looked at the lettering much closer and it looks like the letters are not stamped but laser etched. The only thing that is stamped is the serial number. I found the serial number stamped on the bottom side of the tang as well. Having the serial number in two places makes me think that I can go ahead and draw file the number off the barrel. What do you think?

 

[Birddog6]

It is just up to you. If you want it off, take it off. Just pay attention to the adjacent flats & even them up so it is not obvious you draw filed it off.

Keith Lisle

 

[Goldhunter]

Jim, I meant the tang to barrel fit while draw filing. With the tang and barrel outside the stock I glue them together so there is no movement while filing (to match up the flats).

 

[Flash Pan Dan]

Howdy, I just finished inletting the buttplate and toeplate on my stock. It looks good with out gaps. I also draw filed the lettering off the barrel and tighten and fitted the hook to the tang section. Had to do a bit of peening to get a good fit but that also looks and works well.

Now I tried the barrel and hook tang into the stock and found that the tang area of the stock is very roughly routed out and the tang only sits on a tiny little shelf of wood along the edges. It looks like if I inletted the tang until it is flat in contact with the bottom of the mortise it might be to low for the barrel to fit well in the barrel channel of the stock. As is now, there is still a small gap between the bottom of the bolster and the top of the notch in the lockplate. How should I proceed?

Thanks for your help,

Dan

 

[Zonie]

Use some transfer medium like inletting black or (not your wifes) lipstick.

Apply this in a very thin coating (I use a model paint brush) to the bottom of the barrel and install the barrel fully into the stock.

Remove the barrel and look for places where the transfer medium has been deposited on the wood.

You really do NOT want a gap between the bolster and the top of the notch in the lockplate.

These should be a line to line tight fit so that the lockplate can take the impact of the hammer hitting the nipple.

Sand or chisel away any "high points" where the transfer medium shows.
Work very slowly and carefully. You do not want to remove more wood than is necessary.

When the barrel bolster to lock gap is gone, then you can worry about the fit of the tang.
I suspect that when the barrel is in the right depth, the depth of the tang mortice will be about right.
If it isn't, we can fill up the hollow area with something like Plastic Wood or some other form of epoxy so the tang block is fully supported.

 

[BrownBear]

Well said Zonie, but I'll add this for Flash Pan Dan-

As you fit the barrel, be aware that it's likely to contact the installed nose cap sooner rather than later. I've seen a couple of GPRs with the cap set "high" enough that the barrel rested on that with no wood contact at all until you were most of the way back to the breech.

At some point you're likely to be faced with either lowering the cap or filing the inner surfaces to clear it from the barrel. I've tried both, mostly because I filed the first one (what a PITA), and after that experience I lowered the next to the right position and repinned it. Had to do a little glass bedding for a tight fit, but I'll do it that way again to get around the filing.

 

[Zonie]

I'll add that sometimes it's amazing how just a tiny little bit of wood can prevent the barrel from fully seating out in a stock.

The as cut barrel channel should be close to being right so look for little things that are sometimes difficult to see.
When they are removed suddenly, plunk! It all fits together like it should so check your progress often.

 

[Flash Pan Dan]

Thank you both for your advice. I will put some inletting black on the barrel and tang and see what kind of work I have left to do in the barrel channel. I’ll try and take a picture of it to get your opinions on it.

 

[Flash Pan Dan]

Here is where I’ve gotten to so far. I inlet the barrel and tang to this point. My question is; should I do a bit of metal work to make them fit or should I do more inletting? The nipple and hammer are lining up pretty well right now. Opinions?

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[Flash Pan Dan]

Okay, I have inlet the barrel to where it now is touching the notch in the lock plate. But the bolster is slightly forward of the center of the notch in the lock plate. According to the instruction, which came with the rifle, I should now remove the lock and inlet the barrel the rest of the way and then take a file to the bolster and fit it to the notch in the lock plate.

First of all, “inlet the barrel the rest of the way” is a bit nebulous and second if the bolster is forward of the notch, even slightly, won’t I have do quite a bit of filing on the bolster for it to fit in the notch? I’m a bit puzzled. Any help you can lend is much appreciated.

Dan

 

[hed0014]

Dan,
How does the rear of your tang fit? Is there room to move the tang and the barrel back?

 

[Flash Pan Dan]

Yes, there is plenty of room except that the tang bolt is already drilled and there is a threaded washer imbedded in the stock for it. So if I want to move the barrel and tang back I would have to pull out the washer plug the hole and redrill the tang hole. That seems like a lot of work for maybe a 1/32 of an inch offset. I was hoping someone might have a solution short of having to redrill the tang bolt hole.

 

[Flash Pan Dan]

Howdy all,

Well, I finished inletting the barrel, lock, trigger, and trigger guard. It was a little tricky getting the lock, bolster, nipple and barrel to all line up correctly. Not hard just tricky. Had to blacken and inlet a little a time and putting everything on and taking it off until I got the bolster to nestle into the notch on in the lock plate and the lockplate in solid contact with the side of the barrel.

I am about 80% done with the rough shaping using the rasps and files. Boy, there is a lot of wood to take off. One thing that bothers me right now is the lock bolt inlay. The hole for it in the stock is so oversized that it rattles in there and falls out. It does not look good. Any one have an idea as to I might remedy that condition?

Thanks,

Dan

 

[Col. Batguano]

I have a similar thing going on with a barrel pin. Big channel developed that made me miss the estrucheons' hole on the outside of the stock. I went to the hardware store and got some epoxy putty and packed it in there around the pin channel. Before it had cured, I retracted the pin leaving just the void for the pin. Yeah it's ugly, but it's hidden, and at least functional.

 

[Flash Pan Dan]

Is the thread pitch on the tang sight hole 8x40? It seems to be the same as the screws that hold the barrel rib, is that correct?

Thanks.

Dan