In December of 2004, I bought a police trade in Glock 22 to turn it into a USPSA Open Division pistol. I intended to lighten the slide, port the barrel, and mill a pocket to mount a Docter Optic Sight II into the slide. Ultimately I planned on a caliber conversion to 9mm Major, which USPSA had legitimized around the same time. These first pictures show my Open Glock after it’s Stage I modifications, still in .40 caliber.
The most apparent modification are the ten flared 3/8″ diameter port holes down the sides of the slide. Four right and six left. These port holes removed a good several ounces from the slide, which I returned to the reciprocating mass when I attached the Docter Sight to the slide. But these were not the only cuts made, an Open Gun needs to be ported and this pistol was indeed. I milled open the top of the slide, similar to a model 34. And cut four large rectangular ports down the center line of the barrel.
The first port’s rear edge is 2.7″ from the breach face. This gun was literally a blast to shoot. Both for the shooter as well as any near by bystanders. Zero muzzle flip. However, recoil was brisk, with the pistol moving straight back into the web of the shooting hand.
The Stage II modification was eliminating the adapter plate and mounting the Docter Sight into the slide its self. There was no one offering this service at the time. I did this on a manual milling machine. Reverse engineering the dimensions for the pocket cut, mounting screws, and recoil pins from the Docter Sight itself. While not as clean in appearance as a CNC cut mini RDS pocket, it is functional. And with the four full recoil pins, I never had the issues with loosing zero when removing and replacing the sight from the slide.
Stage III was the conversion to 9mm Major, which was based on a KKM Precision Glock 35 conversion barrel. I threaded the barrel to add a comp I made. The compensator was a simple two chamber with six ports design milled from 7075 aluminum stock. Unfortunately I never took an pictures of it in this configuration.
I used Vihtavuori’s published load for 3N38 with 147gr XTPs. I used Zero 147gr JHPs in my loading. My gun never achieved the 1207fps with the book max load. Its 5.3″ barrel only making 1180fps, which was still good for a 173pf. I never ported the 9mm barrel because of this. Fearing not being able to make major power factor if I did.
As a 9mm Major Open Gun, this Glock was a pleasure to shoot. None of the blast like the ported .40 barrel and soft mild recoil. And it was very pleasing accurate. I think the quality of KKM’s barrels is well known as are that of VV powder and Zero bullets. That combined with the precision and ease of sight alignment offered by the 3.5 MOA dot made this pistol seem like a laser.
You may have noticed that I am taking about this pistol in the past tense. It died during local club match, after only a few months of shoot 9mm Major. Cause of death: over exuberant gunsmithing. Seems the two additional port holes on the left side turned out to be a bad idea.
I don’t feel to bad about because Glock has made a similar mistake with the model 34. They put an internal lightening cut right through the same area. Which makes the 34 not suitable for use as a 9mm Major platform.