set trigger screw

[snapper]

My Frank Bartlett rifle has a double set trigger.  The adjustment screw is really hard to get to with the trigger bow, and the screw seems to be frozen in place.  If I need to replace the screw, is there a standard size for these screws and if so, where would I get a replacement?

thanks

fleener

[EC121]

This screw often get rusted during browning.  I usually use a small needle nose pliers to break it loose.  Put a drop of penetrating oil on it and let it sit overnight first.  It might free up.  Frank used Davis triggers a lot.  Track and others sell parts for both L&R and Davis or go direct to the manufacturer.  The websites will also give the screw size if you want to try to get locally.

[bama]

Frank did use a lot of Davis triggers as they are a good trigger and Frank only used good quality parts.

I have used a bunch of these triggers myself and have found that this screw to be difficult to thread in and out of it's tapped hole when the triggers are new. I believe that this is hole is tapped with a tapered tap and that the tap is not run all the way through the hole but is stopped short leaving the last few threads not completely cut.

I allways dissasemble these triggers while inletting and finishing. On many I notice that the last few threads of the screw are  flatened or slightly rounded. I think this is becasue the tap was not run all the way through the hole. This makes for a very tight fit. I believe that this is done to keep the screw from viberating loose during shooting.

This makes it almost impossible to adjust this screw once the trigger guard is in place. I try to set the engagement where it is safe but light with as little movement of the front trigger as possible to dissengage the set trigger at the final asssembly stage of the build and I am sure Frank did the same thing.

I would suggest removing the guard to make an adjusment if needed. This is the only way to do this safely. If you use plyers you stand the chance of breaking this small screw off or just buggering it up.

Sometimes you can get a small long shanked screwdrive into the screw slot depending on the width of the bow on the guard but if you cannot do this then I would pull the guard.

[D. Taylor Sapergia]

Many of these screws are #2 x 56.  You can purchase similar screws at electrical supply stores.

Others use #3 x 56 and rarely, 4 x 40.

[Hungry Horse]

 I had a similar adjustment screw issue with a gun I was working on for a friend. The screw was too short to do any adjusting in the first place, and inaccessible in the second place. I found a socket head capscrew(Allen) that was the correct thread count, at the local parts house. I turned the square shoulders off of the head by chucking it in a drill, and running agains a file, to produce a peppercorn shaped head that looked more appropriate, and cut off an Allen wrench to do the adjusting.The only way to see the socket head is to turn the gun upside down an peek behind the trigger guard. By the way these capscrews are almost always grade 8, and take some time to reshape. If I had this to do again, I think I would chuck the screw in a drill, and run the head against a grinding wheel.

     Hungry Horse

[David R. Pennington]

I always thought putting a slot head screw in an inaccessable place made no sense so I made a screw for a set of triggers I made with a round head and drilled two tiny holes through the head at right angles so a vent pick could be inserted to turn it. I case hardenend the screw then. I like the threads to be a little tight so the adjustment stays where you set it. This picture isn't real good but maybe you can see what I mean.

[P.W.Berkuta]

I always thought putting a slot head screw in an inaccessable place made no sense so I made a screw for a set of triggers I made with a round head and drilled two tiny holes through the head at right angles so a vent pick could be inserted to turn it. I case hardenend the screw then. I like the threads to be a little tight so the adjustment stays where you set it. This picture isn't real good but maybe you can see what I mean.

Smart -- and nice job of drilling that screw head .

[snapper]

thanks all for the info.

I had taken a screw driver bit and cut it down to fit into a small ratchet that I could get into the bow area.  I have also used Kroil for a few weeks.  So far nothing has worked. 

I might get to the point of a pair of pliers but want to make sure that I can replace the screw.

A little heat with a micro torch might be the next step.

Fleener

[Smoketown]

Craftsman and a few others made a 'screwdriver' that had two different thickness flat blades at either end of a bar.

Each of the blades were ground at 90 degrees from the one below it.

You would turn the screw as far as you could with one blade then roll the bar between your finger tips then take a bite with the other bit and do it again.

Tedious but it worked.

It would be great for adjusting the set trigger screw.

Cheers,
Smoketown

[Nate McKenzie]

Has anyone ever found a knurled head screw in these sizes that could be turned by hand?

[P.W.Berkuta]

Has anyone ever found a knurled head screw in these sizes that could be turned by hand?

My answer is "no". To knurl a head that size it would be cost prohibitive to manufacture, you would first need to make the tool holder & cutters for the small head of that size screw - can it be done - sure -but I don't think there is much of a market for it and that screw might be $20.00 or more .
I just thought of maybe a watch maker but I think that screw would be in brass???

[Dennis Glazener]

I would love to find a knurled head screw like the one on this Philip Gillespie rifle. The one on my Mathew Gillespie rifle (Philips father) is missing). If I remember correctly I tried one of the Davis screws and it was the same thread.
Dennis

[Howard]

I love those triggers!!