Lyman GPR Triggers

[Scota4570]

I have been tasked with re-building a GPR kit that was never properly completed. I have lots of experience with scratch building and gunsmithing in general.

This is a mass marked "price point" gun, I expect very little.

The triggers in particular have me puzzled though. The set triggers work. The lock works. The hammer falls from full cock just fine if I set the triggers. If I do not set the triggers, the pull on the front trigger is over 30-pounds.

The front lever is located such that it is pushing forward on the sear bar more than it is pushing up. The top of the front trigger lever is an odd shape. It is also too low causing a huge amount of take up. There are no wood fit-interference problems. Just horrible geometry.

Before I re-engineer the rifle, is this normal for a GPR?

 

[MSW]

disclaimer: i have never taken a Lyman apart

comment: that can't possibly be right

intuition: a powerful force of nature!

 

[54ball]

I'm tempted to tell you to run from this. #2... mass produced mediocre parts and the biggie, # 1...having to fix someone else's screw ups. The deck is stacked per say.

First...
Look for any wood in the lock or trigger inlet interfearing with function.

Second...
I would look into the trigger assembly. Maybe there is some roughness where the blades contact. I would tune and slick up the triggers. Maybe disassembly and a good polish of the frictions surfaces of the trigger assembly would help. it can't hurt.

Third...

I would do the same for the lock. A simple polish of the tumbler and friction surfaces may be of some great benefit. I would not go into the notches unless there is a obvious bur.

Maybe just a good polish of the lock and trigger assembly will be enough. You may be surprised.

No luck....

Trigger location, depth and location of inlet...all that geometry.

Still no luck, may be time to tune the lock and work on the full cock notch.

 

[BrownBear]

I haven't diagnosed the construction to your level of detail, but the symptoms you describe match perfectly with my own experience using Lyman triggers. They suck in the unset-pull department.

The RE Davis Deerslayer Trigger is the perfect solution. Best $50 you'll ever spend on any muzzleloader. Unset pull is somewhere around 3# and crisp. It's so good in fact that I almost never set the trigger.

Note: Davis sezz it's for a TC, but it's a virtual drop-in on the Lyman GPR. I've installed something like a dozen of them over the years and only one required any inletting. That one called for shaving a few molecules of wood from one side of the trigger plate inlet.

 

[Scota4570]

Good tip on the Davis trigger. See how the Davis has the front trigger blade sticking up high? That is what I would do to make the original work right. I'll order a set ASAP.

It sure looks to me like Lyman deleberatley made a crappy trigger. It looks like lawlers redesigned it to work poorly.

The project is for a friend, actually his son. I owe him, so I will make it right, and pretty, regardless of the issues.

 

[bubba.50]

as you say, that odd hook-shaped front trigger bar causes poor trigger geometry. the Davis's will greatly improve it as will even a set of T/C triggers.

 

[Zonie]

If you do decide to get the Davis trigger, you have nothing to lose if you try to rework the existing triggers.

You say the top of the front trigger blade (or lever) is an odd shape and it is too low.

That could mean there is room to file the odd shape so it is flat and at a better angle for pushing against the sear arm.

Then, by soldering or brazing a piece of flat steel to the top of the blade you could kill two birds with one stone.
The height would be corrected and the new, flat surface of the added steel would press on the sear arm at a better angle.

 

[BigBoreBLR]

I use the set trigger, but have it turned up as heavy as it can be. So, it's a single trigger with an extra step.

I've heard, but not seen a "downgrade" to a lymand trade rifle single trigger.

 

[MSW]

I haven't diagnosed the construction to your level of detail, but the symptoms you describe match perfectly with my own experience using Lyman triggers. They suck in the unset-pull department.

The RE Davis Deerslayer Trigger is the perfect solution. Best $50 you'll ever spend on any muzzleloader. Unset pull is somewhere around 3# and crisp. It's so good in fact that I almost never set the trigger.

Note: Davis sezz it's for a TC, but it's a virtual drop-in on the Lyman GPR. I've installed something like a dozen of them over the years and only one required any inletting. That one called for shaving a few molecules of wood from one side of the trigger plate inlet.

didn't know that Davis made a trigger for Lyman... i put on in a T/C rifle some years back and it's a huge improvement ... BrownBear is right - money well spent!

 

[bubba.50]

I haven't diagnosed the construction to your level of detail, but the symptoms you describe match perfectly with my own experience using Lyman triggers. They suck in the unset-pull department.

The RE Davis Deerslayer Trigger is the perfect solution. Best $50 you'll ever spend on any muzzleloader. Unset pull is somewhere around 3# and crisp. It's so good in fact that I almost never set the trigger.

Note: Davis sezz it's for a TC, but it's a virtual drop-in on the Lyman GPR. I've installed something like a dozen of them over the years and only one required any inletting. That one called for shaving a few molecules of wood from one side of the trigger plate inlet.

didn't know that Davis made a trigger for Lyman... i put on in a T/C rifle some years back and it's a huge improvement ... BrownBear is right - money well spent!

it's the same Deer Slayer trigger as the T/C uses.

 

[longcruise]

I've never figured out what that odd shape is for on the Lyman front trigger. But, the geometry is such that it has little possibility of functioning properly.

I have built four of these kits and all four ranged from a unset trigger pull of 15 to 50 pounds. Another that I purchased factory built for a family member was equally useless.

There is no inlet changes possible to fix the problem. You can polish and lube the triggers and lock to perfection but it won't solve bad geometry!

If you want to retain set trigger function, then the deerslayer is probably the best (and a good) solution.

For my own two rifles I have found that when shooting with the set trigger reaching for the front trigger puts my hand in an awkward position on the trigger guard. For myself, the ideal position for the firing trigger is where the set trigger is at the rear.

So, my solution was to make and install single triggers. It hasn't hurt my accuracy and is, IMO, a better system for hunting. One is built with a post on the trigger plate so as to allow interchangeable triggers. The single trigger works so well that I saw no reason to ever put the set trigger back in so on the second one I pinned the trigger through the stock.

So, since the deerslayer is a good solution, my only reason for this epistle is to suggest that you have the future shooter heft the rifle and see if he might, like myself, prefer the fit of a single trigger.