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GPR set trigger screw

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highbrow

32 Cal.
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I have a 50 cal GPR flint with a long creepy set trigger. The adjustment screw doesn't change anything. Is there a replacement screw that will help this?
Thanks in advance.
 
There have been a half dozen threads about this in the last year or two, including size and source for the correct screw. Sorry I don't remember those sizes, but you can dig it up pretty easy with a site search.
 
Yep, there's a lot written in the past about that.
I installed a Davis Deer Slayer in my GPR.
Although there was nothing really wrong with the Lyman trigger, the difference was like night and day. Very simple shave job and it drops in. Functional set screw too, Best 40 bucks you can spend on a GPR, IMO, of course.
Looky Here
 
highbrow
As you found, the adjustment screw doesn't fix things, even if it is screwed in all the way.

I don't know why Lyman doesn't contact the maker and have them fix this problem but to the best of my knowledge they haven't.

What you need is a longer screw, and I've forgotten what the size is but I do know it is one of the metric sizes.

I suggest that you remove the screw and take it to a hardware store or an auto parts store that carries small metric screws and have them measure it. Then buy one that is at least 1/8 of an inch longer and install it.

This screw only adjusts the engagement of the set trigger blade (rear trigger) with the sear of the front trigger. It does not adjust the loose pre travel, over travel or the release of the hammer when the lock is not set.

I strongly recommend that in the interest of safety you do not set the release so fine that by just touching the front trigger it will release the hammer. Set in this condition the front trigger sear may not engage the rear set trigger blade securely enough to keep small bumps to the gun from firing it.
 
When I got my GPR about 20 years back I had the same complaint. I called Lyman and was referred to Dixon's Muzzleloading Shop. The gentleman I spoke with at Dixon's said that the trigger setup was due to liability concerns. He did say I could replace the adjustment screw with a longer one. The closest standard screrw size is 2-56, which will probably be a little loose. I was fortunate enough to find the correct metric size, with adequate length, among the screws from a broken pair of binoculars I had taken apart.

I suggest you take the existing screw to a watch repair shop or a jewelry repair shop. They deal with tiny metric screws regularly and might have just what you need.

Good luck!
 
Picked up a "mini machine screw" 2.5x8 for 30 cents. Works perfectly. The trigger now has no creep and can be adjusted for what ever pull you need. Mine is now 1 lbs. :thumbsup:
 
The standard metric screw in the 2.5mm size is a
M2.5 X 0.45 thread.
The first number is the diameter of the screw at the tips of the threads and the second number is the distance between the tips of each thread.

The standard Metric series of threads does not have fine and course pitch screws in this size range but it is a good idea to ask for the entire thread size number just in case someone has a metric screw with a bastard thread pitch.

In this case, the full name of the screw would be a M2.5 X 0.45 X 8mm.
 
Zonie said:
The standard metric screw in the 2.5mm size is a
M2.5 X 0.45 thread.
The first number is the diameter of the screw at the tips of the threads and the second number is the distance between the tips of each thread.

The standard Metric series of threads does not have fine and course pitch screws in this size range but it is a good idea to ask for the entire thread size number just in case someone has a metric screw with a bastard thread pitch.

In this case, the full name of the screw would be a M2.5 X 0.45 X 8mm.
Well, yes there actually is a fine metric thread spec in this size range. It's 2.5x0.35. See Fine metric thread specs.

However, in this case the thread is the coarse 2.5x0.45 already mentioned.
 
I dunno about anyone else and their local friendly Ace hardware store, but I seem to suffer from slobs digging in the screw bins before I get there. No matter what the label on a bin, there are often several sizes mixed together.

Easy solution for me was to take my Lyman screw into the store and use it to find a nut that fit perfectly. Then I took the nut and dug into the bin to make sure I picked screws that threaded right.

One further detail--- In our Ace store, there wasn't a perfect screw. They were either shorter or a full 1/4 inch (6mm?) longer. Don't recall the size of the long one, but that's what I took home and shortened to suit.

Made the gun happy and made me happy.
 
I picked mine up at an ACE HARDWARE. They only had one screw and it was in a small bin with washers. :nono: Had to go through the whole drawer to find the only screw that size. They had several 2.5x12 screws, so I got a couple of those and cut 'em down to size and they worked fine.
 
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