View Full Version : Boy, Do I have new respect...

August 18, 2000, 02:39 PM
...for the metal used in aftermarket mags.

I decided I wanted witness holes in my aftermarket mags (got tired of counting), so I marked them off with measurements from my factory Sig mags, and tried to drill a few lousy 1/8" holes in the mag body. My test case was a Millet blued mag. I stripped the mag, used snug-fitting wood blocks in the mag body to support the metal, center-punched the holes, chucked a "titanium-tipped" bit in the press...and nothing. And believe me, I was HONKING on that press. NOTHING. Barely a scratch. I switched to a DeWalt "cobalt-tipped" bit and had the exact same results.

So, anyone got any ideas on what to bore through these mag bodies with? Some kind of high-energy laser!? Faster/slower speed? I figured being aftermarket, they would be relatively soft metal, but no way. And, I still have 12 stainless steel aftermarket mags to do, and I can only imagine what they'll be like. Any help would be appreciated.



August 18, 2000, 02:47 PM
Was your drill in forward? ;)

Seriously, you can drill through damn near anything with a drillbit, except stuff like chrome. If you can't drill through it, probably isn't the mag, it's probably the bit. Still, it sounds like you've got some nice heat treated mags.

I twist the facts until they tell the truth. -Some intellectual sadist

The Bill of Rights is a document of brilliance, a document of wisdom, and it is the ultimate law, spoken or not, for the very concept of a society that holds liberty above the desire for ever greater power. -Me

August 18, 2000, 03:36 PM
Believe me, the direction was the first thing I checked, because, to be truthful, I've SEEN it happen before. Never to me, of course. :)

But seriously, I did check, and the bits were brand new.


August 18, 2000, 06:01 PM
Try slow speed with lots of oil using another new bit. Sounds like you really got some tough mags there!

August 18, 2000, 08:02 PM
pilot tiped bits cut better with less force and speed.

August 18, 2000, 09:41 PM
your mags are made of tempered steel. You won't be able to "drill" through them. What you need to do is go and get a 2 flute 1/8 diameter carbide cutter, set it up in a drill press and cut the holes in the clips. You should use something to keep the cutter cool too. Probably motor oil.

August 18, 2000, 10:45 PM
A "carbide cutter." You mean, like for a router (or my Dremel)?

Is the motor oil to cool the bit so the metal doesn't "work harden," or just to preserve the bit?

Thanks for the ideas.


James K
August 18, 2000, 11:41 PM
Those sound like goog mags. Most of the after market mags today are not hardened at all, which is why there is so much trouble with them.

A carbide bit should cut through.


Badger Arms
August 19, 2000, 12:03 AM
When Drilling Titanium and other hard metals, the general rule is "slow speed, heavy feed pressure, and lightweight oil." The lightweight oil is for coolant as well as to lower friction. The bit will still cut, but there will be less resistance. The Millet Mags were VERY tough and VERY good metal. These aren't your average aftermarket mags.

August 20, 2000, 08:14 AM
go to a good machinery supply store and ask for a 2 flute carbide cutter. 1/8th diameter (i guess thats what diameter you want) the motor oil is for cooling and to keep the chips loose. Yep use slow rpms and heavy feed the cutter should punch through very quickly so don't slam it through the other side and break it.

700PSS Shooter
August 21, 2000, 12:13 PM
I had the same experience with the "Shooting Star" .45 mags in blackened stainless when drilling for bumperpads. Finally used carbide tipped drills, but boy were they tough.

September 2, 2000, 12:37 PM

They have zillions of bits.

Brownell's also sells carbide bits for getting through case hardened steel.

September 3, 2000, 10:29 AM
Thanks for tip. I got a tungsten carbide cutter for the drill (pointed), and I'm going to try that, and I'm going to try Brownells and J&L if I'm still stuck.

September 5, 2000, 10:18 AM
Sounds like you have some good steel mags. Two or three years ago I put witness holes in three of my Sig 226 USA mags (used measurements from a factory mag), and all that I used was a household drill and vise with a block in the mag body. The only prep I did was tapping a small ding into the spot I was going to drill through to give the bit a spot to get into the steel. It took me less than a minute to drill through at a low speed. I just have not reblued them (talk about procrastinating) where I filed away the burrs.

Futo Inu
September 5, 2000, 04:55 PM
On a tangent about "titanium-tipped" drill bits: I see these advertised, but isn't this just a scam? In other words, hardened steel is significantly harder than titanium, no? Titanium is so popular/useful because of it's WEIGHT, and therefore WEIGHT TO STRENGTH RATIO. Sure it's lighter, and has a lower weight to strength ratio, but weight is a negligible non-issue when your goal is to drill through something really hard. ABSOLUTE HARDNESS is most important then, and steel wins that battle, no? Diamonds, maybe, but I don't think titanium is going to help at all compared to a steel drill bit.

September 5, 2000, 09:04 PM
I may be wrong, but I thought titanium was "harder than steel, lighter than aluminum." That's just what I'd heard about it. But yes, I'd just use a diamond-steel bit.