2 weeks of penetrating oil and heat cycling finally did it

[1KPerDay]

I have three old replica colts from the late 60s... best guess after researching is ASM but they are completely defarbed and “antiqued.” I have been trying to figure out a timing problem with the 3rd Dragoon but I couldn’t get the right rear back strap screw to budge. Broke a couple of my good gunsmithing screwdrivers. The slot is very thin so the tool has to take a lot of stress. Anyway I soaked it in PB Blaster for a few days and broke another screwdriver. I cycled it with a propane torch and kept reapplying oil and checking every couple days. Tonight it finally came free.

So then of course I promptly lost the left rear screw somehow. I don’t understand this. I only had one screw out. I had it on a magnetic pickup tool so it wouldn’t get lost. I finally got the frozen (right) screw out. I picked up the screw off the magnet thing. And now I can’t find one of the screws. The one that was on the magnet. It’s like it vanished. I’m completely flummoxed.

Check out the verdigris and decades years worth of dust and oil. It’s only been shot once to my knowledge and that was 30 years ago.

 

[entropy]

Persistence pays off.

 

[Bibbyman]

I loose more screw and other parts while using a magnetic screwdriver than a regular screw driver. Parts get picked up and dropped off in "parts unknown".

 

[1KPerDay]

Don’t know where I’m going to find a replacement. I guess I’ll go try to match the threads. The head is pretty thick top to bottom though.

 

[entropy]

Start with Track Of The Wolf; then Dixie Gun Works.

 

[1KPerDay]

The rear two trigger guard screws appear to be identical to the top backstrap screws if that give anyone a clue as to who made it (which I doubt it does)

 

[arcticap]

If you can match the threads, McMaster - Carr has many different types of socket head screws in metric sizes.
They have larger heads, maybe you'll find one that works.

Here's an example of alloy steel: --->>> https://www.mcmaster.com/screws/soc...t-head-screws-8/system-of-measurement~metric/

All socket head screws. --->>> https://www.mcmaster.com/screws/socket-head-screws/ Left hand column has link for inch and metric threads.
All fasteners. --->>> https://www.mcmaster.com/screws

 

[1KPerDay]

Whaddaya think? Thread pitch looks wrong, right?

https://www.gunpartscorp.com/products/782790F

Couldn't find anything at TOW.

 

[1KPerDay]

If you can match the threads, McMaster - Carr has many different types of socket head screws in metric sizes.
They have larger heads, maybe you'll find one that works.

Here's an example of alloy steel: --->>> https://www.mcmaster.com/screws/soc...t-head-screws-8/system-of-measurement~metric/

All socket head screws. --->>> https://www.mcmaster.com/screws/socket-head-screws/ Left hand column has link for inch and metric threads.
All fasteners. --->>> https://www.mcmaster.com/screws

Yeah, I'm going to take it to the hardware store and try to match the threads so I'm not shooting in the dark. I'm sure after I order/buy something I'll find the lost screw.

 

[1KPerDay]

What are the chances these will match?
https://www.gunpartscorp.com/products/780190C

According to the diagram the backstrap screws and rear trigger guard screws are the same part number, so that's good at least.

 

[1KPerDay]

Well it’s not metric, which I don’t understand. It’s a standard size 10x24 by about half inch (not including the head). One store didn’t have anything with a similar diameter head, so I’m looking elsewhere. At least I know the size and pitch now.

 

[1KPerDay]

Any tips for reducing the diameter of a screw head? Chuck it in a drill and use a file?

 

[LNK]

Any tips for reducing the diameter of a screw head? Chuck it in a drill and use a file?

Yup, that is what I do. A lathe would be nice....

 

[Jackrabbit1957]

VTI has screws, look under ASM parts either Walker or Dragoon. 1/4 24 thread pitch, price is like $4.00 each.

 

[1KPerDay]

VTI has screws, look under ASM parts either Walker or Dragoon. 1/4 24 thread pitch, price is like $4.00 each.

1/4 x 24 is different from size 10 x 24 isn't it?

 

[LNK]

1/4 x 24 is different from size 10 x 24 isn't it?

By a good margin. #10 @24 tpi shares the number of threads per inch though.

Can you post a picture of what the screw you need looks like? I have ground down allen head cap bolts, and cut a slot for a slotted screw driver with a file. Can even sulphur blue the screw after. Just do it outside, the fumes will not make you happy, your lungs either.

 

[TheRodDoc]

The type of screw you need is called a - Slotted Fillister Head Screw - Brownell's has them but only in 1 inch length. You will have to cut them to the length you need.
https://www.brownells.com/gunsmith-...-screws/fillister-head-screw-kit-prod394.aspx

 

[Armored farmer]

My sympathy for you for the list screw. I havr done similar so many times....it makes you think you might just lose your mind next.
One sure way to find it, is to replace it. It will show up soon afterwards.

 

[webrx]

i usually get out a strong mechanics magnet, and run it around my work area to see if I can pick up the lost screw, found a missing bolt and an allen wrench and a nail in the rocks in my back drive when I dropped the bolt working on the kids truck this way.

d

 

[MikeJackmin]

Turn off the lights and lay a flashlight on the floor. It makes little things look big.

 

[electricfactory]

I'm amazed you didn't damage the screw head! I have the same exact situation going on with an 1858 Remington NMA trigger guard front screw. I've applied all manner of penetrating oil as best I could, slobbering it over the screw over many days.I haven't tried a propane torch. The screw head slightly damaged but not destroyed and now I don't quite know what to do next, not wanting to mess it up any more than I have already. I can't submerge the entire gun in penetrating oil- can I ?

I have three old replica colts from the late 60s... best guess after researching is ASM but they are completely defarbed and “antiqued.” I have been trying to figure out a timing problem with the 3rd Dragoon but I couldn’t get the right rear back strap screw to budge. Broke a couple of my good gunsmithing screwdrivers. The slot is very thin so the tool has to take a lot of stress. Anyway I soaked it in PB Blaster for a few days and broke another screwdriver. I cycled it with a propane torch and kept reapplying oil and checking every couple days. Tonight it finally came free.

So then of course I promptly lost the left rear screw somehow. I don’t understand this. I only had one screw out. I had it on a magnetic pickup tool so it wouldn’t get lost. I finally got the frozen (right) screw out. I picked up the screw off the magnet thing. And now I can’t find one of the screws. The one that was on the magnet. It’s like it vanished. I’m completely flummoxed.

Check out the verdigris and decades years worth of dust and oil. It’s only been shot once to my knowledge and that was 30 years ago.

 

[Dave Markowitz]

I can't submerge the entire gun in penetrating oil- can I ?

As long as you take off the grips, why not?

 

[LightninST]

Brownells driver & bits , you only need to replace the tip of you damage one.
Many sizes to fit just right
Good job on getting it out , sorry for your loss it happens .

 

[J-Bar]

As long as you take off the grips, why not?

Agree. Get a cheap plastic tub from the Dollar Store, soak the gun in a mix of automatic transmission fluid and acetone (from the paint store) for a few days. It’s close to Ed’s Red, the magic penetrating solution. Stir it up a couple times a day and let it work in there.

 

[1KPerDay]

Try heat. Try turning the screw in before turning it out. Heat it and reapply oil and wait. In my case I couldn’t get the grips off so submerging it wouldn’t work.