ASG STI Duty One 1911 Blowback CO2 BB Pistol Review


Type: BB air pistol.
Manufacturer: ASG.
Model:  ASG STI Duty One 1911 Blowback.
Materials: Metal slide and polymer frame.
Weight: 1.8 pounds.
Barrel: Metal non-rifled.
Propulsion: CO2 x 1.
Action: Semi auto blowback, single action.
Ammunition Type: 4.5mm BB's.
Ammunition Capacity: 20 round magazine.
FPS: 383.
Trigger Pull: The trigger pull on the ASG STI Duty One 1911 is nice and light due to its true blowback operation that cocks the hammer back with each shot taken. The pull is rather long but nothing really happens till you get right to the end and then there is just a slight bit of pressure and a quick release.
Accuracy: I shot the STI Duty One 1911 air gun at a target from 20 feet away in a free standing position, and it performed well getting a 1.5 to 2 inch grouping right in the center of the target. The rear sight is adjustable for windage which is always nice to have just in case you are shooting a bit to the left or right. For me there was no need to adjust the sights. My Chrony testing with an eight shot averaged result was 373 fps - very decent for a blowback pistol!
Build Quality: ASG did an awesome job designing and making the STI Duty One 1911 Blowback BB gun, they didn't really compromise on anything other than the polymer frame! With that said all that important parts like the Slide, Slide Catch, Safety, Mag Release, Hammer, Barrel and Magazine are all metal. The fit and finish as with all the ASG air guns is excellent!
Realism: The ASG STI Duty One 1911 Blowback is a really close replica to the real steel STI 1911, the only real giveaway is the trigger design, as a true 1911 trigger is not your typical lever type. Even with the different type of trigger the STI Duty One is a very good replica complete with all the STI licensing and trademarks.
Purchased From: The Replica Airguns Store.


  • Realistic true blowback action.
  • Adjustable rear sight for windage.
  • True single action blowback gun.
  • Excellent quality control. Very well made, fit and finish is excellent
  • Good power, accuracy, and CO2 efficiency for a blowback gun.
  • Metal dropout magazine.
  • Good STI Replica.
  • Extremely enjoyable gun to shoot!


  • Trigger is not true to the real 1911 style.
  • Has a polymere frame, not metal.
  • I found the CO2 kind of hard to get out.

I am quickly realizing that ASG is a company that makes not only some really nice air pistols, but also ones with excellent quality control and design. The STI Duty One 1911 Blowback CO2 BB gun is no exception to this and I found it a blast to shoot because it felt great in the hand, shot hard and on target, performed flawlessly and I was able to get a lot of shots from a CO2 even with the blowback and high fps for a blowback shooter. If you're a 1911 fan or you simply like full size guns that mean business, then take a look at the ASG STI Duty One 1911 Blowback CO2 BB pistol. If I had to pick one BB shooter to take out for a day of plinking, this would probably be the one!

My YouTube Video Review for this quality Airgun:

4.5mm / .177 cal, BB, Blowback, CO2, Field Test, Pistol, Review, Semi Auto, YouTube Video ASG, STI Duty One 1911