How to port your own barrel


August 29, 2006, 05:44 PM
I have a question for you true gunsmiths:

Can a person take a stock pistol barrel (Glock), and port the barrel himself?

I have hundreds of drill bits, etc in my shop-- So can I simply drill a number of holes in the barrel, or is there something I am missing?

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Jim Watson
August 29, 2006, 06:08 PM
You mean like the burrs left in the bore when the bit breaks through?

August 29, 2006, 06:30 PM
I agree, never a good idea. You will never be able to evenly de-burr the holes, and your accuracy will go way south! Send it to Magna-port.

August 29, 2006, 09:17 PM
Do they machine it or do they use EDM [electro-discharge machining ] ?

August 29, 2006, 09:27 PM
EDM I believe.

August 29, 2006, 10:02 PM
Ports are EDM machined. The holes must be of the correct size, shape and angle. A drill is no good. Internal burrs aside. So no, you can't port it yourself.

August 30, 2006, 08:49 AM
OK first, I'm not a gunsmith (at least not a "professional" one)...But I have ported 2 barrels (1 rifle, 1 shotgun)myself with good results. Here's how I did it:

I marked and aligned the barrels in my drill press vise. Used a prick punch, then a center drill to get them started. I then used a regular drill to drill MOST of the way through. Then I used an end mill EXACTLY the same diameter as the drill bit to "finish" the holes, going nice and slow. Lots of lubrication during drilling and milling. No visible burrs, and the rife shot just as good after I did it. (Hard to tell if there was any difference with the shotgun). If there were any microscopic burrs, I'm sure the first few rounds did away with them. Obviously YMMV, but I wouldn't be afraid of doing it yourself with the proper tools (In fact I'm about to do another one).

August 30, 2006, 09:58 AM
Unless you have a machining background (which I don't) I would not attempt this simply because I can have someone do it for me, and if they screw it up, they replace my barrel. If I screw it up, I have to buy another.

Sounds interesting though, but getting those burrs out sounds tricky, which is why I'm sure the pros that do this for a living use EDM, no burrs that way.


August 30, 2006, 11:43 AM
Back years ago, when I had an FFL, Larry Kelly of Mag-Na-Port used to do the porting for me. One day, as I sat in his office, sipping coffee and talking with him, admiring the many trophies in his office while waited for my Remington 700 Classic in .338 Win Mag. to be Mag-Na-Ported, I asked him specifically how does the process work. I had two concerns: burrs remaining and lost velocity. He said tests showed no more than typically 25 FPS reduction, and no burrs could remain becuase, “…we don't drill. The electric process ionizes the metal. It simply vaporizes.”

When I returned home, I went to the range to test fire the rifle and measure the velocity. No loss of velocity. Don't try it yourself. Mag-Na-Port only charges $125ish for the process and it will be done right.


August 30, 2006, 11:09 PM
Since the barrel and slide recoil together until the bullet leaves the muzzle and relieves the internal pressure, you would also have the get the holes in the barrel to line up with holes in the slide, or cut relief slots in the slide, like an OEM C-model Glock. That would be the really dicey part, IMO. Or use an extended barrel that protrudes from the slide and put the holes there.

I'm not a true gunsmith, however. ;)

Jim Watson
August 30, 2006, 11:15 PM
I have a couple of shotgun barrels ported with a ball-end mill, which is less likely to leave a burr than a drill bit, per dfaugh. They shoot ok but I would not want to try it on a rifled barrel of any quality.

There was an article about a guy who made his own Olympic Rapidfire barrel complete with pluggable ports. He poured the barrel full of Cerrosafe and drilled into that, going from one metal into another instead of breaking completely free avoided burring.

August 31, 2006, 01:53 AM
My wife gave me a Mossberg 12 Ga Combo shotgun as a gift. Both barrel have a series of porting holes in them. The shotshell barrel had a huge hole in the bottom of the shot pattern. I looked inside the barrel and all the porting holes had burrs on them. It took my two hours to get them cleaned up. Got rid of the hole in pattern, too.

Now, twice so far I broke 23 out of 25 on the trap range. So, I'd say the gun works. Now to get me shooting skills working better :banghead:

Steve Wynn
September 4, 2006, 02:52 PM
You can't beat the work that Kenny and Mag-na-port does. The EDM process leaves no burrs on the inside of the gun. You may even want to have some other work done on the gun while in MEEEEESHEEGUN!


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