Another GPR Trigger question

[Gonetocamp]

I read about my issue on some forum but don't recall where. Other posts here come close to my question but not quite. I removed the gpr trigger plate (and lock) and adjusted (messed with) the screw between the triggers and the screw behind the set trigger and also the mainspring screw. I succeeded in reducing the pull weight to set the set trigger, and the firing trigger is fine after setting the set trigger. However, when not using the set trigger and using only the firing trigger, pulling the firing trigger causes the hammer to move slightly forward prior to the break occurring with continued trigger pull. I suspect this is a sear release issue. Do I address it via the screw between the triggers?

 

[longcruise]

To adjust the set trigger, you need only work with the adjuster between the trggers. Not sure what you may have done to it. Was the trigger pull that difficult before you worked on it? GPR triggers are notorious for hard pull when not set. Many shooters replace with an aftermarket set trigger.

 

[Zonie]

If the hammer moves at all when the unset front trigger is pulled, you are correct. It is a issue with the sear and tumbler notch.

The heavy pull required to set the rear trigger is an inherent problem with the GPR trigger and, as you've found, the screw under the big rear trigger set spring is the way to reduce it.

Even using this screw won't lighten it a great deal. It's just part of the design.

The small screw between the two triggers is there to adjust how much engagement the front trigger has with the rear triggers catch. It really doesn't adjust the weight of pull necessary to release the previously set rear trigger.

The irony of that screw is the company who makes the gun (Lyman just imports it) made the screw so short that it really never reaches far enough into the trigger assembly to even touch the front trigger.
In other words, the short screw actually adjusts nothing.

Some folks have replaced that screw with a longer screw with the same threads. I don't recall what the thread size is but it is metric.

 

[Gonetocamp]

Thanks Marmotslayer and Zonie. I will put it back the way it was for now.

 

[Zonie]

I don't recall suggesting that you put anything back the way it was.

I've also changed the adjustment on the rear set trigger spring to reduce the rear set trigger springs pressure on my GPR.
The way it comes from the factory is WAY too heavy.

The catch with adjusting this spring pressure is, if you go to far, the blade on the rear trigger won't have enough energy to trip the sear.
If this happens, although the rear trigger when set will "snap" when the front trigger releases it, it won't have enough energy to knock the sear arm up to release the tumbler.

 

[jethro224]

The Davis Deerslayer triggers made for the T/C Hawken were a drop-in fit on my GPR. Mine cost about $40 several years ago, not sure what the price is now. They are a huge improvement.

 

[don hepler]

I have explained the muzzleloader trigger issue, both here and other sites. In a modern rifle, the trigger and sear are joined mechanically, because they are connected. However, in a muzzleloader, the trigger is set in the wood in one location, while the lock, is set in wood in a different location. The set trigger, just loads up the front trigger, under spring tension, so when the front trigger is pulled, it flies up and slaps the trigger bar which is attached to the lock. If you just use the front trigger, you are pushing the trigger arm, against the arm on the lock. It must over come the main spring tension and the amount of sear engagement. On production guns, it is difficult to change the geometry of the front trigger, and still have it as set trigger. If you reduce the mainspring, you will slow the lock time. If you reduce the sear engagement, at the full cock notch, you might create, a dangerous hair trigger, and with wear might not work at all, or ruin the tumbler altogether.

Hope this helps, understand the workings of a muzzleloader set trigger.

In an after-market trigger, the manufacturer may have addressed the geometry issue of the front trigger, giving some improvement.

 

[Gonetocamp]

I seem to have stumbled onto an acceptable setting of the various adjustment screws. Thanks to all for the comments/advice. Another benefit to my efforts is that I am now over some of the fear of adjusting (messing with) my first flintlock.

 

[Billnpatti]

I ran across the same problem with a Pedersoli lock on a rifle that I used to own. The problem is one of lock geometery. The full cock notch is cut at the wrong angle. It angles back slightly rather than being square with the trigger sear. This causes the tumbler to have to rotate back slightly before the trigger sear is released from the full cock notch. This results in a heavy trigger pull. The problem can be corrected by a gunsmith who specializes in muzzleloading locks but may be beyond a gunsmith who works only on modern guns. There is a man who tunes locks and does a fine job on them but he isn't cheap. I think he used to work with The Log Cabin Shop but maybe someone on the forum can tell you who he is. Other than spending the money to have it tuned, you can just use the set trigger to set the lock before firing.

 

[Maven]

"The irony of that screw is the company* who (sic) makes the gun (Lyman just imports it) made the screw so short that it really never reaches far enough into the trigger assembly to even touch the front trigger. In other words, the short screw actually adjusts nothing."

Gonetocamp, Zonie's right, but the good news is the correct longer screw is available from Dixon's.


*Investarms

 

[BrownBear]

The Davis Deerslayer triggers made for the T/C Hawken were a drop-in fit on my GPR. Mine cost about $40 several years ago, not sure what the price is now. They are a huge improvement.

Yup. Same experience here on a number of GPRs, my own and those of friends. It's such a good fix, I wouldn't even pull the factory trigger if I got a new GPR today. I'd go right to Davis for the replacement.

Best thing about it is when you use the front trigger without setting the rear. It's clean and crisp at a little under 3#. So good in fact that about the only time I set my trigger is for bench testing. That crisp unset trigger is a boon for hunting when the chips are down and you have to make the shot without pausing for a trigger set.

 

[longcruise]

I have always been satisfied with the function of the GPR set trigger when used in the set mode, but trying to shoot unset is more like a fitness exercise! Not willing to spend the money on an aftermarket. Just rubs me wrong. The vast majority of my shooting is at paper with no more than a few shots per year on game. Have yet to lose an opportunity because of the click, so it is a non issue for me but those Deerslayers are surely the best solution!