Umarex HK45 CO2 NBB Steel BB gun

Total: $49.99

Type: BB Pistol
Manufacturer: Umarex
Model: HK45
Materials: Metal and Polymer
Weight: 1.4 lb (635 g)
Barrel: Smoothbore
Power Source: CO2
Action: Semi-Automatic, Double Action
Ammo Type: 4.5mm Steel BBs
Ammo Capacity: 20 Rounds
FPS: 420

Buy the magazine: UMX2252305

Trigger Pull: Trigger pull on the Umarex HK 45 Metal Slide CO2 BB Pistol is double action only but doesn't feel too bad, it has the traditional longer double action pull but I did not find it to be too heavy and the release point was fairly predictable for me allowing for some good overall accuracy.

Accuracy: I got a bit higher FPS then claimed at 420 FPS with a 5 shot string using a brand new CO2 with RWS 5.1 grain zinc coated steel BBs. From 30 feet away shooting on a paper target using a semi rested posting I was able to place 10 BBs within 1.5 inches, almost close to a 1 inch grouping. The shot placement for me was just a tad to the left and a bit down but several shots hit the bulls eye so out of the box accuracy was really good on this low cost BB pistol.

Build Quality: The Umarex HK 45 Metal Slide CO2 BB Pistol is built fairly basic with few moving parts so there is not much to go wrong, the fit and finish is good and there is metal where it needs to be internally and also the trigger, magazine and slide.

Realism: The Umarex HK 45 Metal Slide CO2 BB Pistol is a very good overall HK 45 replica in terms of size and looks, it has full HK licensing and even has a metal slide and polymer frame like the original real steel HK 45. It is a bit lighter bit not by too much. There is no working slide and the slide catch/release and hammer are molded into the gun. The only working parts would be the safety, magazine release and trigger.


  • Inexpensive overall decent BB gun
  • Good accuracy and power
  • Metal where it matters, slide, magazine, trigger, internals
  • Nice replica of the original HK 45
  • Fully HK Licensed
  • White dot sights easy to sight in your target on most backgrounds
  • Decent double action trigger
  • Picatinny rail for accessories


  • None blowback with a fixed slide
  • Slide catch/release and hammer are moulded in and none functioning
  • Sights are none adjustable

Comments: For a rather low cost CO2 4.5mm steel BB pistol, the Umarex HK 45 has a lot going for it! It is fully HK Licensed with a metal slide and metal parts where you want and need it. The accuracy and power are both good and even the double action trigger is very usable. Sure the Umarex HK 45 Metal Slide CO2 BB Pistol is a pretty basic gun with few moving parts but then again simple is sometimes better in terms of reliability. If you are an HK fan and want a low cost well made and good performing BB pistol then checkout the Umarex HK 45.

Caliber:4.5 mm (.177 cal)
GunBarrelLength:12.4 cm (4.87 inch)
FPS:400 to 450
Ammo Type:Steel BB
Power Source:Co2
Rail Type:Picatinny
Trigger Action:Double
Blowback Action:Non-Blowback
Front Sight:Blade
Rear Sight:Fixed

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Umarex HK45 Metal Slide CO2 BB Pistol Field Test Review

Umarex HK45 Metal Slide CO2 BB Pistol Field Test Review

515 - 11/14/2021 12:43:18 AM

In this Field test Shooting Review I again get out from under my deck roofing and take my Chronograph and target shooting onto the pool patio. I may as well take advantage of the great summer weather we are having and get some rays while I shoot a video :) The CO2 BB Pistol I chose for this Field Test Shooting video is the Umarex HK45 Metal Slide CO2 BB Pistol. As per my usual Field Test Shooting Video Reviews, I test out the real world velocity (fps) for the Umarex HK45 BB Pistol by shooting 5 rounds through my Chronograph using a brand new CO2 and using 5.1 grain RWS zinc coated Steel BB's. I did have a few Chronograph issues but managed to get 5 good readings giving me an average of 421 fps. Read full article here: Buy the Umarex HK45 BB Pistol in Canada: Buy the Umarex HK45 BB Pistol in the US:

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