Type: Non-blowback CO2 BB Pistol.
Manufacturer: Distributed by Crosman.
Model: MK45.
Materials: Mostly plastic.
Weight: .63 pounds (281 grams).
Total Length: 7.25 inches (184mm).
Barrel: 4.5 inches (114mm) metal non-rifled.
Propulsion: 12g CO2 x 1.
Action: Semi auto non-blowback, DOA trigger.
Ammunition Type: 4.5mm steel BBs.
Ammunition Capacity: 20 round drop out metal stick magazine.
FPS: Claimed 480.

Trigger Pull: The Crosman MK45 CO2 NBB BB Pistol has a typical double action tiger with a longer trigger pull that requires more length and effort to pull, but we would say is still usable as an action shooter. The Crosman MK45 trigger pull makes the internal metal barrel move forward and out of the front of the barrel opening a bit, then when you reach the release point it snaps back into the BB Pistol acting like the hammer and releasing CO2.

Accuracy: As promised we first test the velocity in fps by using a brand new 12 gram CO2 in the Crosman MK45 CO2 NBB BB Pistol using 5.1 grain 4.5mm steel BB’s. The temperature was around 20C/69F so about average room temperature. Our fastest shot out of the Crosman MK45 was 424 with the slowest shot hitting 406 so pretty consistent. This gave me a 418 average fps which is a bit under the claimed 480 fps Crosman states. Still more than acceptable for plinking at cans and other unsuspecting objects 30 feet or more away. Next we made sure we had 10 rounds loaded in the Crosman MK45 CO2 NBB BB Pistol’s 20 rounds stick magazine and set myself up 30 feet away from a fresh pepper target. We generally use a seated shooting position with our hands rested on a sandbag up front and seated on a stool like chair in the back. We did get a couple flyers but we would say the Crosman MK45 is more than capable of getting all 10 shots within a 1.5 to 2 inch grouping. The stragglers this time around stretched it out to more like 3 inches so still not bad. The sights on most of these lower cost CO2 BB pistols are generally fixed and the Crosman MK45 CO2 NBB BB Pistol is no exception so it is a good thing it shot really close to the bullseye out of the box.

Build Quality: The Crosman MK45 CO2 NBB BB Pistol is a pretty much an all plastic Airgun with only a few metal parts we can find on it. The trigger is metal along with the inner barrel and the area where the CO2 goes in. Because of the plastic build, it is rather light weight which can actually be good in a fall as the mass is low resulting in less damage if you were to drop it on a hard surface. Scratches will also be less noticeable on a plastic Airgun over a metal Airgun as the material on a plastic Airgun is all tan/black rather than a painted surface that will show blemishes a lot more. The simplicity of the design means you should get a lot of use from the Crosman MK45 CO2 NBB BB Pistol before encountering any issues.

Realism: The Crosman MK45 CO2 NBB BB Pistol is not a replica of an exact real steel gun in production but it does share a lot of cosmetic characteristics as what you would see on a Sig Sauer or even H&K Pistol. The magazine release on the Crosman MK45 looks and works a lot like what you will find on an H&K Pistol. There are few external mechanical working parts on the Crosman MK45 CO2 NBB BB Pistol other than the trigger, safety and inner barrel. The barrel is slightly recessed and the CO2 tab is hidden in the grip which helps in terms of believability.

Pros:

• Desert tan with black grips looks really good in my opinion.
• High FPS rating of 480.
• Picatinny rail on frame for adding on accessories.
• Non-blowback should get lots of shots per CO2.
• Easy to see fiber optic sights front and back.
• CO2 tab is nicely hidden inside the grip.
• Double action trigger pull is long but not too firm.
• Uses a generic all metal stick magazines commonly found on lower cost BB pistols.
• Ambidextrous magazine release.
• Simple design with not a lot of moving parts will make it reliable for a long time.

Cons:

• All moulded plastic BB gun for the most part.
• Not many working parts, it’s pretty much an all plastic BB gun.
• Grips are fairly loose, they don't really snap into place.
• Sights are not adjustable.

Comments: We personally prefer blowback Airguns that have a more solid weight and feel to them with more working parts, but again there is a lot more that can go wrong and parts tend to complex parts wear out over usage a lot quicker than a more simple design like in the case of the Crosman MK45 CO2 NBB BB Pistol. Price is also going to be a lot less when looking a more simplified Air Pistol like the Crosman MK45, as the plastic build is a lot cheaper to produce. Another bonus with non-blowback CO2 airguns is that they do tend to have a much higher velocity and also generally you will also get more shots per CO2 than a similar CO2 Blowback Pistol. It really depends what features you want more and in this case you also get a more cost effective Air Pistol with plenty of shooting enjoyment. A couple other strong points to mention about the Crosman MK45 CO2 NBB BB Pistol would be the fiber optic sights front and back and its sharp l looking two tone layout.