Gunsmithing Help an idiot drill a hole and tap it!

[71firebird400]

First off, I have <span style="font-weight: bold">zero</span> machinist experience! I'm wanting to drill a hole in a Ruger Revolver (investment cast frame) and thread in a set screw. The diameter needed will be 6-40 or so (this will be used for a trigger over-travel stop, so the set screw can vary a bit in size).

For all of those on this forum who could do this in 2 minutes, can you help me out? What size hole should I drill, and what tap should I use? Is there anything special I'll have to do considering it's cast stainless steel?

Thanks!

 

[seanh]

Re: Help an idiot drill a hole and tap it!

which revolver?

 

[2Shots]

Re: Help an idiot drill a hole and tap it!

Are you drilling the trigger for the screw to stop over travel or the frame?

 

[71firebird400]

Re: Help an idiot drill a hole and tap it!

It's a GP100 and I intend on locating the set screw in the trigger guard (which is a detachable piece on the GP100). I've seen it done on Redhawk's which share a similar construction, which is why I want to attempt it on this gun. Here's a picture I found on the internet, I drew in a black line where I want to drill the hole.

 

[2Shots]

Re: Help an idiot drill a hole and tap it!

Wow, I'm only an amateur gunsmmith and can only advise you to only do it if you had at least a drill press and vise to work with. I don't think I would try it with a hand drill. That stainless can be pretty tricky some times and that's a pretty deep hole to keep straight. I'm not sure I wouldn't look at drilling the trigger somewhere, at least if you screw it up you can get a new trigger. I have twisted off taps and broken drills in stainless pistols before for friends doing them a favor for free and had to pay a gunsmith or a machine shop to fix it! Good luck! Maybe a real gunsmith can advise better than me.

 

[Edds]

Re: Help an idiot drill a hole and tap it!

If all you have is a hand held drill and no experience, you need to get someone to drill and tap that hole for you.

 

[Walt K]

Re: Help an idiot drill a hole and tap it!

My first impression is to recommend that you don't do this job. If you don't know what tap drill size to use and what tap to use you are a bit behind the curve. No offense. I realize that you want to do a DIY job but maybe you should try something else first or get some experienced help.
I've never worked with cast SS steel but I have worked with non magnetic SS and it can be a real b***h. Your cutting tools must be very sharp because SS can be very tough and stringly to machine. If your cutting tool is dull or you don't use the proper speed and feed ( and coolant, lube) the SS steel may work harden and then your really screwed. Also small taps can be very easy to break.
Think about it, ask around.

 

[jrm850]

Re: Help an idiot drill a hole and tap it!

The only way you are going to be able to drill and tap a hole that many diameters deep would be to counterbore a large portion of it at major diameter.

 

[seanh]

Re: Help an idiot drill a hole and tap it!

I've put them in both trigger and frame...trigger is much easier.

You don't need a drill press but it would be easier to do--less likely to have any wobbling of the bit, you'll keep the hole straight.

if you decide to go with the hand drill, you'll need a good center punch to help that bit stay centered...you'll want a vice and some method of lining up the drill straight (hanging a plumb bob- have a drill that has x,y bubble level)

 

[71firebird400]

Re: Help an idiot drill a hole and tap it!

Sean,

Maybe the trigger would be a better idea; did you punch the hole through the trigger face when you've done this?

 

[cal50]

Re: Help an idiot drill a hole and tap it!

WESCOG=
Wiley E Coyote School Of Gunsmithing

I would suggest something else as your 1st tapping job.

 

[stangfish]

Re: Help an idiot drill a hole and tap it!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cal50</div><div class="ubbcode-body">WESCOG=
Wiley E Coyote School Of Gunsmithing

I would suggest something else as your 1st tapping job. </div></div>

A couple of things to consider. A small diameter tap like that can break real easy if you torque off center when you are cutting. If you want to try it, I would buy several taps and practice in a vise and use a #32 drill rather than a #33. Be careful!!!!!

 

[seanh]

Re: Help an idiot drill a hole and tap it!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 71firebird400</div><div class="ubbcode-body">Sean,

Maybe the trigger would be a better idea; did you punch the hole through the trigger face when you've done this? </div></div>

Yes, I drilled through the trigger completely.

the hardest part is deciding where to put the hole...close to the tip, middle or higher up. For me it all depends on the customer and gun. Some customers don't care where it was, just put one in. Others didn't want to feel it which limits it's location.

For me, I didn't really care, the hole was small enough that I really didn't feel it.


As mentioned above, you'll want to be very careful in tapping...some stainless has a tendency to work harden making tapping difficult.

Edit: One thing you can do is to use some CA glue (superglue) to fill the hole in the trigger once you've set the over travel. Easy to sand, chip and remove if necessary

 

[Kebo57]

Re: Help an idiot drill a hole and tap it!

find a pic of a High Standard 22 Semi auto target pistol....the stop/overtravel screw is in the trigger but there is a boss on the back side to give the screw stability and to keep the end of the screw away from the trigger finger...as others above have said the screw through the trigger would be the best bet and easiest to do correctly.

 

[stangfish]

Re: Help an idiot drill a hole and tap it!

Sean makes a good point about work hardening with a drill. Use a new bit and keep steady preasure with lower RPMs for stainless.

 

[LRI]

Re: Help an idiot drill a hole and tap it!

FireChicken guy,

I got your PM. I think I'm going to pass on this one. The parts look like castings to me and that is an invitation to trouble when poking holes through parts that see the loading/shock/abuse that a trigger shoe almost certainly experiences in a revolver.

I appreciate the offer from you though.

Next and forgive me and my ignorance. I often see a great deal of shooters that insist on minimal overtravel on their triggers. I come from a NRA Highpower background so maybe this is an apples/oranges type of discussion that does not apply equally across the board.

But if it does, consider this:

Firing a double action, single action trigger in a pistol is not all that dissimilar from shooting a rifle offhand. To do it well often requires a more aggressive trigger pull. When you "see it" the shot needs to break in that instant.

Now say your doing this and shots are habitually breaking low in relation to where you last saw the sights. You could be anticipating the recoil which is a fairly common problem with pistol shooters.

It could also be from conservative overtravel. The hammer has to swing. That eats time. Your finger is still moving to the rear once the sear lets go. IF your finger/trigger bangs against an OT stop prior to the hammer getting the fires lit, pressurizing the case/chamber and sending the bullet on its journey to destruction it would seem very possible to me that it would cause a low shot plot.

Dunno for sure on a pistol but I do know that it can raise all sorts of hell on a rifle. Most Highmaster/National Champion level NRA course guys/gals that I know take all the overtravel they can get because the offhand portion demands aggressive trigger control and they don't want to disturb the sights after the shot breaks.

Just maybe something to consider.

Good luck.

C.

 

[71firebird400]

Re: Help an idiot drill a hole and tap it!

Thanks for the advice everyone, I appreciate it. I think I'll skip this project as it sounds like there's a lot more involved than I was initially thinking.

Chad, you bring up a lot of interesting points that honestly I've never heard from anyone before! I shoot the gun well, I was just attempting to make the trigger feel more similar to my Python's as I have a general preference for them. I don't necessarily think there's a problem to solve here (as far as accuracy as concerned), it was just a matter of opinion more or less. Regardless, I truly enjoyed your insights on the matter and will leave "well enough" alone.