chasing 6-48 threads?

[824tsv]

I have a Model 41 barrel that was factory drilled and tapped. I've tried installing a Weaver#62 mount. Using blue locktite on the supplied screws will not hold them in the barrel. My belief is that the supplied screws are to short but now the tapped holes are full of locktite residue that the longer 6-48 screws that I purchased wont screw in. I've tried cleaning the tapped holes with Hoppes and a q-tip but that doesn't seem to do much. My only solution is to purchase a thread tap to chase the threads. Is this a reasonable solution or is there something else I can do?

[mikerjf]

Sometimes a pin with a bent tip can clean out threads. (I refer of course to the “common pin”, not a firearm “pin”. Something small and pointy.)

If you get a tap, remember that common taps are not threaded at full diameter clear to the end. For a shallow blind hole you may need a blind tap.

[03gringo]

mikerjf gave good advice. I think the tool you need is called a "bottoming" tap to clean those threads at the end of a blind hole.

[oldman10mm]

Other forums show success with Carb & Choke cleaner, Brake cleaner, Acetone. These items can damage finish.
I like the bent pin tip idea.
A #6 thread is pretty small in diameter, about .135".

[andy52]

Originally Posted by 03gringo

mikerjf gave good advice. I think the tool you need is called a "bottoming" tap to clean those threads at the end of a blind hole.

^^^^^^^^^
What he said.

[toad67]

Do the holes go thru the receiver, or just part way? If they go thru, then I would just get a chamfer or plug tap, remove any part of the action that is below the hole(s), and run the tap by hand, and it should clean out fairly easily. The difference between the two taps is the amount of taper on the starting end of the tap. Since you already have threads, either one should start easily.

Brownell's 6-48 plug tap:
Plug Tap, 6-48, 31, 25 : BROWNELLS HIGH SPEED STEEL TAPS | Brownells

If the holes don't go thru then you need a bottom tap. These taps have very few tapered threads on the starting end of the tap, which should clean out the threads almost all the way to the bottom.

Brownell's 6-48 bottom tap:
Bottom Tap, 6-48, 31, 25 : BROWNELLS HIGH SPEED STEEL TAPS | Brownells

If the threads are buggered up, you will need an oversized 6-48 tap, style depending on whether or not the holes go thru.

Brownell's .146-48 oversized taper and bottom taps:
.146"-48 Taper Tap : BROWNELLS .146'-48' TAPS | Brownells

The bottom tap might be a little difficult to get started, but if your careful they usually go pretty easy.

If you end up having to go the over sized route you will need to cut some screws to proper length.
1 Dz. Weaver .146"-48 Screws : BROWNELLS .146x48 OVERSIZE 6-48 SCREW SHOP KIT | Brownells

Also, make sure your screw threads are good. Going to a LGS and asking for a longer 6-48 screw to chase the threads might be an easy solution also.
If worse comes to worse, I have all three taps, and some screws you could use if you needed too.
Good luck...

[2152hq]

If it's just the threads themselves that are filled with the Locktite and need to be cleaned out, then a bottoming tap will do the job.
Be very careful with them, go slow, as there is no lead cut into the tap threads.

If however the body of the screw hole along with the threads down in that lower depth have been filled with Loctite and you have a solid plug of Loctite solidified in there,, the tap no matter what type won't remove it.

You have to remove the center portion of that plug of Loctite down in there as if you were drilling the hole originally to be tapped. Then use the tap to clean up what remains on the threads.
The tap won't drill & tap in one operation.
I wouldn't try redrilling unless you have a very precise method of set up like a mill and experience .

I don't know what they have, if anything, to disolve Loctite.
Heat will soften it, but it takes anywhere from 300F to 400F depending on the type.
Don't be tempted to heat the stuff in the hole till soft and then remove it with a tap. The chances are great that the softened loctite will solidify once again as you are working on it.
Then you have the tap also stuck firmly in the hole.

300F you can get away with w/o damaging bluing
400F you can also,,BUT, anything much above that and you start to damage the bluing of most hot salt blue jobs.

If the hole needs to be cleaned out/cleared of Loctite before the tap can be used, lacking anything that will disolve it to allow wicking most of it out and then using the tap,,I would use a tiny chisel made from an allen wrench.
Grind and break the short arm off and clean it up. Grind one end to a small chisel edge and use it carefully to chip away down in there and break away enough to allow the tap in there to do it's job.

[Patrick L]

A bent dental pick, along with something "oily" like kerosene, Kroil, or liquid wrench should allow you to clean it out.

You can also take a common 6-48 screw and make a cleaner by cutting a slot in the threads, perpendicular to the thread direction. Work it slowly back and fourth, 1/4 to a 1/3 turn at a time.

Patience is the key with all of these approaches. Go slow and careful!