doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com top screw out of time

Stan,
I don't recall ever reading about the technique, I just ended up working out a sound solution to a problem that appeared in the shop. I'm always doing woodwork and have saws, sanders etc. so making a thin wafer of wood is easy enough. I have done the same repair on the tangs of doubles where there is some wood loss around the rear tang screw. This is pretty much how these problems were addressed before the invent of bedding compound, add some more wood and inlet to the required depth.

I really enjoy seeing high quality vintage wood repairs come through the shop. One of my favorites was a Fraser falling block a client owned, it went back to the factory for a new barrel and top tang safety conversion and fore end was re-used, the new barrel was a smaller diameter and the dutchman used to fill the gap was world class.

I hope that helps.
Steve

in this case adding a shim won't help. The screw head is tapered, so thicker on one side and I need it farther in to enable the top lever to clear it. If I back it out part of the screw head sits up proud.

I'm rather limited on funds and old wood does all manor of things. I shim or add wood and re inlet if needed. Where the shim goes is pretty easy to determine. If the wood is proud at the top tang, shim at the top. If the wood fits perfecta shim under the trigger plate works. Store bought waxed paper works well for minor shims, wood and re-inleting for major stuff. I've had a couple drillings that the side safeties that would bind and a paper shim or two under the trigger plate solved the problem for a couple cents. The drilling now shoots safely and usually brings the tang screws back into proper alignment because the wood has compressed over the years. Because the trigger plate is shorter than the top tang the compression is there.

Okay, so now you have determined what the issue is, now you need to figure out why. The pin could be damaged, so could the trigger plate it screws into. Has the top lever spring been replaced? Sometimes a replacement top lever spring can interfere with your inletting. You can use inlettting black to see if something is stopping the metal from seating to the correct depth in the wood. If the metal fits as it should to the wood, also see if the pin will fully seat in the metal without the wood installed. You mentioned it might be restocked, check to see the pin is not binding on the stock.

Let us know what you find.

Steve

If the screw is turning too far, which is almost always the issue, a shim will help. You may have to try a couple different thicknesses, but something should return it to original spec.

The slot is at 3 o'clock,,but is that the end pf the screw slot that SHOULD be at 12? (overtightened),,or is it the end of the screw slot that should be at the 6 position (not tight enough).

Maybe you have already figured it out, but many time the screw head out of time will display edges around the circumference that are lower or higher than the tang counterbore hole itself.
Those high and low edges can tell you if the screw needs further tightening to time it,,or needs to be backed off too time.

If it's been restocked, that might be what's causing the issue.
Not being able to pull the lower tang into the same position it was on the orig stock,,or it may be that it is pulling the lower tang up just a bit more and over tightening as far as the timeing goes.
Check the draw surface on the stock,,where the slanted front of the trigger boss pushes on the stock.
If a restock, that face of wood may need a very slight shaving down to allow the top tang screw to pull the trigger plate upwards a bit when turned tight and will let you time the screw head if it needs more tightening.
Glue a thin wood slat onto the surface and re-fit if the screw is over tightened.

I've seen plenty of shims placed under screw heads to make them time.
Everything from a loop of very thin wire, to a paper or thin card 'washer', to a washer made from metal shim stock as already mentioned.
The last two, you punch a hole in the center with a common paper punch for the screw shank.
I've seen the bottom outside edge of the screw head peened downward a bit to make the head engage the bottom of the counterbore earlier to tighten things up and time it.
Also soft solder added to the underside of the head to make it bottom out sooner.
There's a method to tighten the draw using nothing but a hammer. I use it quite often on smaller screws. I'll keep the secret,,secret! (it's probably widely known now though.)

My mind is always trying to figure ways to solve problems, and I just thought of this. Steve, Kutter and others who have more experience, please comment.

In lieu of gluing in a thin wafer of wood, then re-inletting the pin to the correct depth, I wonder how well it would work to use cyanoacrylate glue and build it up with a mixture made from it and walnut dust. It should be very easy to control the application of it, and it would seem to me that it would harden sufficiently to provide a solid seat for the underside of the pin head. I know that type adhesive is used to strengthen walnut in areas that are subject to compression and cracking, because in its thinnest form it soaks into the grain freely. Once thoroughly dried, one should be able to relieve the built up area to clock the pin slot.

I have several little jars of walnut dust, in various hues, in my shop that I captured with a belt sander for hiding repaired cracks in stocks, with cyanoacrylate.

The glue solutions are fairly effective.

In situations where maintaining the appearance of originality are not a concern the most effective long term fix is to build steel pillars and fit to length. They capture the screw and give a solid stop. Last the remaining life of the gun.

I did exactly that to the front and rear tang screws on the the two M21’s I competed with. Had no problems related to tang screws or triggers after that. Wish I had done it years sooner.

That should work Stan, pretty similar to bedding compound, not runny and will do the job. I like inletting wood better than a plastic type of filler, so if fitting is required after build up, I prefer wood.

Mr. Potter once shared with me that there are wrong ways to do a job, but quite often more than one good way to complete a repair exists. I think your idea has merit. I use sawdust combined with wood glue or CA myself. Certainly worth a trail run, even if just done a piece of scrap to get a feel for it.

Steve

I wonder how a small O ring placed under the head of the screw might work? O rings come in many different sizes, diameters and material. I only suggesting this might be a possibility. I have never tried this but I would think the O ring might conform and might work. Obviously not a professional repair but might be a quick and easy temporary fix.

I also recall using a very thin cone shaped stainless shim under the heads of #8 and #10 screws where the top material under a nut plate had worn and was slightly oversized and going up another size fastener was not feasible or cost effective. Again I never tried this on a firearm but I need to see if I can contact friends still in the business and see if I can obtain a few to experiment with.Similar to what Stan mentions about making a shim.