L&R lock in GPR

[dodger]

This is a question for those that have fitted an L&R rpl lock into a Lyman GPR.
On my rifle (with standard Investarms lock) the vent hole is not central in the pan and is approx 1/8 of an inch to the rear.
Does the fitting of an L&R lock remedy this build fault and place hole in the centre of the pan?
Thank you.
Dodger.

 

[palonghunter]

Being centered on the pan vertically is probably more important than the horizontal alignment. Does the gun fire reliably as it is now? If not, can you return it to Lyman for a replacement?

I don't think the L&R lock will fix the trouble because it uses the factory screw holes. You might be able to fudge it a little bit but I don't think you'll get 1/8"

 

[dodger]

Thanks palonghunter.
I have done quite a bit of work on this rifle and cannot return it.
I have studied a lot of photos on the internet and read a few postings that outline the fact that many GPR s have this fault.
So , I suppose what I am asking is "did L&R take this into account when they designed their rpl lock?".
Dodger.

 

[Rusty_Nail]

Here is the link to the pdf 8-1/2x11 page from the catalog. Supposedly, locks are full sized on these pages. Printer settings might affect it.

L&R RPL Lyman Lock

I know a small Siler was when I printed and measured.

Maybe print, cut out, and lay on the mortice? It will show where the pan lines up. Will not be exact, but I am thinking maybe close.

 

[dodger]

Ok. I took the plunge and ordered a RPL lock from TOTWwhich arrived in super quick time ( thanks totw and customs! ).
And ?
Well the lock fits in the same position as the Investarms lock , so the vent hole is still 1/8 th of an inch to the rear.
However , the L&R lock is very much better.
Faster lock time .
More positive.
Wider engagement surfaces.
Frizzen actually fully covers the pan,so hunting in the rain should be possible.
Looks more authentic.
This GPR is getting to the point where it is a reliable and functional firearm.
It's been a long haul but I've learned a lot about flintlocks .
Pity that Lyman don't pay more attention to what Investarms make under their name brand.
C'est la vie !

 

[Crewdawg445]

Did you have to remove a good amount of wood? I certainly did, reinforced the areas I felt a little bare with walnut and shaped from there. I also had to plane the lock panel down as my new lock sat lower in the mortise in order to sit flush with the barrel. Definitely worth all the work! Glad to hear it worked out well for you as well! :hatsoff:

Also, drop in an RMC vent liner and she'll go off quicker than a flame to gas fumes!

 

[dodger]

Yes I had to remove quite a lot of wood to accomodate the mainspring and also the wider than original bridle.
Just a tiny amount of filing was needed to make the lock sit flush with the barrel.
The Davies trigger , which I had fitted some time ago, needed the spring tightened to actuate the LPR lock .But works beautifully.

 

[TMan51]

Well the lock fits in the same position as the Investarms lock , so the vent hole is still 1/8 th of an inch to the rear.

That would drive me crazy, (crazier?).

I'm wondering if you could fit a blank screw, and re-drill and tap for a new flash hole 1/8" forward?

 

[Billnpatti]

"I'm wondering if you could fit a blank screw, and re-drill and tap for a new flash hole 1/8" forward?"

I am afraid that when you drill the hole for the new liner, you will drill away all but 1/8 inch of the screw that you used to plug the original hole. With that small amount of thread engagement, I'd be afraid that it could blow out when the gun is fired. I don't know if the repair screw can be welded in place and filed flush with the barrel or even if that would make the repair safe. Moving the whole barrel forward or backward to get a better touch hole alignment may be possible, I don't know. That could be pretty difficult to impossible to do. But, it is an idea worth examining its feasibility.

 

[Zonie]

My advice is don't mess with the vent holes location.

Ideally, the vent hole is centered to the middle of the pan but in reality its forward/aft location doesn't make a lot of difference.

Yes, 1/8 inch is quite a lot but if the vent has direct access to the fresh powder charge in the barrel it should work fine.

After all, when that pan flashes there is a LARGE fireball that envelops the entire side of the barrel in front of the fence and aft of the frizzen.

 

[dodger]

As I am a welder by trade ,I could weld the hole shut and drill and tap for a new vent hole and be confident of it's integrity.
However that's quite a big job for little gain.
I've shot the gun today and as long as the pan is full and powder is heaped towards the vent hole she will fire the main charge ok.
Maybe I'll open up a lobsided cone shape on the vent liner to direct the flame.
Btw I found out today that a brass cleaning jag makes a fine flint knapper - give it a try!

 

[Stringbean]

I have no doubts that you are a fine welder. I was going to do some welding on a barrel of mine to plug some holes. Long story... After determining that the barrel was made from 12l14 I decided against it. I didn't dare try to weld it for fear that the lead in the steel would make for a dreadful weld job. Not sure if your barrel is 1137 or 12l14? I would be curious to your thoughts on welding 12l14.

 

[F.G. Ford]

Hi,
To help center the flash hole, you can grind the back portion of the pan, which will help center the flash hole to the center of the pan.
Fred

 

[bpd303]

My thoughts exactly. Have done that several times.

 

[dodger]

Unfortunately the wall of the L&R pan is too thin .
It would have been possible with the Investarms lock though.

The vent hole of the GPR is positioned within the breechplug,I think I'll try to find a replacement breechplug and measure it carefully to see if that will cure the problem.

Thanks for all the great input guys , much appreciated!

 

[dodger]

This guy can explain far better than I ever could. www.weldingtipsandtricks.com/tig-welding-12L14.html

 

[ptaska]

Dodger, thanks for the update on the RPL lock. My Lyman Trade Rifle made in 2014 was certainly rushed through production. The barrel tang is arched to much and stands proud of the wood, leaving a 1/8" gap between the tang and the tang mortise. The stock cracked behind the lock because there was too much tension between the barrel and the stock. And the frizzen gaps and doesn't cover the pan. I bought the rifle second-hand on the internet. I'm done with buying things on the internet, methinks. It's worth fixing, for sure. Your experience gives me hope.

 

[richdeerht]

One way to relocate a flash hole is to go to a larger thread bushing. The trick here is to enlarge the hole only in the direction you want to move the hole, prior to tapping the larger thread. The GPR has a 6mm thread. If you go to a 5/16" or 3/8' bushing, you can 1/16 or so of movement. Yes, I have done this.

Another option, although with a larger diameter thread bushing is a "Dutch" bushing with an offset flash hole. I've seen this done, too.

 

[dodger]

Mmmn these Lyman/Investarms are a bit patchy in quality eh?
Before you embark on improving that rifle with a new lock etc ,bear in mind that you are going to be putting a couple of hundred dollars into it .
The money may be better spent on a new rifle and the old one disposed of on ebay or something similar.
I have recently bought a Pedersoli Sharps and I am very impressed with it .
If I was looking for a factory built flintlock ,I would be very likely to go the Pedersoli route.
In the meantime I'll persevere with the Lyman ,but I have an itch at the moment that only a smoothbore fowler can scratch .It's going to be fun researching what's available and checking them out.
Flintlocks are seductive and Blackpowder is addictive , I'm not looking for the cure!

 

[kingsax26]

And this reminds me why I sold mine. It was not a bad rifle however I feel that for the price you pay for one you should not ahve to sink several hundred dollars into "improving" things that should be done right in the first place