View Full Version : Drilling a 1911 slide

08-01-2008, 11:26 PM
Hi All,
Been lurking here off and on....great group!
Time to ask a question!
Need advise on how the drill the deep holes on a 1911 slide for the extractor and firing pin without the drill wondering off center.
Any help would be greatly apriciated.

08-01-2008, 11:29 PM
Peck drilling and flood coolant to remove chips? Start with a spot drill, then drill with a screw-machine length drill if possible. Finish with a reamer for exact size.

That is how I would *try* it. I'm no expert!

p.s. Welcome aboard!

08-02-2008, 06:44 AM
This is something I'd do in a mill. Make sure the work is exactly in line with the spindle. The drill has to be sharp and ground even. If in doubt , use a new drill.The biggest reason holes wander is improperly ground drills, or dull drills. Center drill first. Center drill first. Like fast said, peck drill, clearing the chips as you go. use plenty of oil and Do Not crowd the drill.The second biggest reason holes wander is a rushed job, patience is the key here. If you're going to ream the hole, use a drill .010 smaller than the finished hole size. Don't crowd the reamer either and use plenty of oil there too.

08-02-2008, 06:46 AM
Work alignment and center drilling are important. Can't stress that enough. If done right the drill will always follow the center.

08-02-2008, 07:20 AM
Excelent advice .

Perhaps this will be a better place to ask.


IIRC it is a .207 - .210 hole thru.

Steve Steven
08-02-2008, 11:05 AM
Finished Colt slides are HARD. Is this an unfinished one, still soft? If so, you can do it. No real need to harden it, many WWII slides weren/t hardened. Do you have a drawing to follow, as the holes may be shaped or of different diameters inside.


08-02-2008, 11:18 AM
Yes it appears it is stepped from .272 +.003 in from end about .200 deep then it is .207-.210

Paul Alciatore
08-02-2008, 04:33 PM
I have fired and cleaned the weapon many times, but can not remember any of the details of the slide design. Also not knowing your level of experience, I would add two additional cautions.

First, I would not attempt this without a solid work holding set up. The slide should be securly clamped down either with a vise or some clamps. This will greatly help to prevent any wandering of the drill. As stated above, a mill/drill would be a better machine to do this on.

Second, if there is any deviation of the surface you are drilling from completely flat and perpendicular to the intended hole, I would not use a drill. A milling cutter would be far less likely to wander across the surface. Holes are routinely started at angles of 45* or more in this manner. Finding the right sizes of milling cutters could be hard but you could start the hole this way and enlarge it with drills and finally reamers.

08-03-2008, 08:56 AM
Thanks for the advice. This work will be done in a mill. This particular slide is unfinished and stainless. I thought it would interesting to see if I could take one from this state to an operational slide!
I posted over in the Homegunsmithing forum in the 1911 section but no replies yet. It is a good group too!
I will probably need some more advice as I get into this! You guys are great!

08-03-2008, 01:50 PM
I think drilling .03 undersize before reaming might be better than .01. YMMV

Your Old Dog
08-03-2008, 05:27 PM
I am not so sure the slides are all that hard. I've engraved at least 10 of them over the years and they cut like any blued Smith or Colt revolver to me.