Umarex Glock G17 Blowback Action Model
A first look at the long awaited CO2 pistol Part 2 Part 1
By Dennis Adler
I have said this before but it is worth repeating, a good air pistol doesn’t have to be a training gun but a CO2 training gun has to be a good air pistol. The Umarex Glock G17 qualifies as both. One of the most important features a training gun must have is correct dimensions so that it can interchange with holsters, magazine pouches, and primary accessories used with its centerfire counterpart. Even if you are not looking for a training gun, have no intention of ever owning a centerfire G17, it should at least fit in a G17 holster. When the Umarex Glock G19 came out earlier this year it failed that requirement by being a fraction oversized through the triggerguard which prevented it from fitting into or locking in any G19 level 1 or higher injection molded holsters. It fit tightly into an ASG Strike Systems injection molded Level 1 tactical holster made for a basic size gun, and it fit into almost every leather holster I tried. Leather gives, injection molded holsters don’t.
The first thing I did after unpacking the G17 was pick up the gold standard of Glock 17 and Glock 19 holsters, the Blackhawk Serpa Concealment Holster. If the Umarex model fits the Blackhawk it will fit all law enforcement and civilian Glock 17 rigs. And it fits the Serpa like a G17. This is the first test for the new CO2 model and it passes.
If the holster fits…
Since the Umarex Glock G17 fits the Blackhawk Serpa Level 2 triggerguard locking holster for the centerfire pistol, the CO2 model should have the exact same dimensions as the 9x19mm. This is the second test, not that it makes the gun better, but it shows that Glock and Umarex went the extra distance to get this blowback action model right. I gave you the specs on the centerfire model in Part 1 so here is how the CO2 model stacks up visually, and with a tape measure.
Specifications: Glock G17 Third Model/Umarex Glock G17 Third Model
Overall length: 8.03 inches/8.03 inches
Barrel Length: 4.49 inches/4.49 (internal length 4.25) inches
Height: 5.47 inches/5.47 inches
Width: Slide 1.0 inches/1.0 inches
Safety system: Safe Action/manual safety
Weight: 24.87 oz/27.0 oz (with empty magazine)
What does this reveal? The one tiny flaw in the design, the manual safety, which is basically a mandatory item for an air pistol (and there’s lot’s of grey areas in this as we know, but Umarex and Glock went by the book). The manual safety is hidden under the dustcover in the frame recess occupied by the serial number plate on centerfire pistols. It is a simple sliding safety that you can leave set to fire and forget about. But, since Umarex did not use a functional Glock Safe Action trigger, if you were to try and pull the trigger from the side without engaging the blade safety the CO2 model will still fire, whereas a centerfire pistol will not discharge the pistol unless the blade moves back in unison with the trigger. This is not so much a training issue as it is an air pistol safety issue. Why have two safeties and increase the cost of manufacturing if the gun has to have a manual safety fitted anyway? The blade safety on the CO2 model does pivot like an actual Safe Action design and pulls with the trigger, so when you look at it that way, you really can’t fault Umarex or Glock for eliminating a working Safe Action trigger.
Short Blowback and Shorter Blowback
There are two basic types of blowback action designs used for CO2 pistols, a very close approximation of the John M. Browning short-recoil, locked-breech design with a tilting barrel and fully functioning barrel lug and slide ejection port interface, and the less exact, shorter recoil design where the slide does not move as far back as it does on a centerfire pistol or a CO2 pistol using the full Browning design. I pointed this out in Part 1 regarding the locked back slide and what you can see when you remove the magazine. With the design used for the Glock, and a number of other blowback action air pistols, you mostly see the firing mechanism fixed to the frame under the slide and an opening where the top of the magazine fits. When you look at a CO2 model that has an operating system duplicating most of the J.M. Browning design, and we’ll use the Umarex S&W M&P40 as an example, you see the business end of CO2 mechanism, but below that you look straight out the bottom of the grip. This design also allows authentic field stripping of the gun, whereas the Glock-type system does not allow you to disassemble the pistol at all.
Is there any upside to this? Remember that word I hate to use, “compromise”? A shorter blowback design doesn’t use quite as much CO2 to operate and the upside is a little higher velocity. Most blowback action BB models using a Browning-style design have an average velocity of 300 to 320 fps. The Glock hits an average of 365 fps, the report is medium-loud and there is enough kick in the action that you know you have pulled the trigger on a fairly powerful CO2 pistol. In other words, it is a very good “compromise”.
In part 3 we strap on the G17 in the Blackhawk Serpa and head to the test range.