The Western Arms ProKiller Airsoft Gun

I have always been very found of gas blowbacks, although they do tend to be a little unreliable. Then again, they are a back up, so they don't need to work all the time. And while I have owned and toyed around with several, I have never really had one that suited me or that I liked enough to hang on to. Western Arms guns have been spoken of highly for quite some time, and the amount of accessories (slides, frames, grips, hammers, triggers, mag wells, etc.) and upgrades available are almost mind boggling. With that in mind, I decided it was time to take a look at another one and hopefully find a suitable GBB that I liked and enjoyed. I did quite a bit of research into the WA line of guns, and found that the Prokiller MK II hasn't seemed to get a lot of coverage. The Prokiller Limited 2000 has been reviewed a few times, but not this newer and still available version. So why not take a look a look at it now and spark a bit more coverage of it.

When the Prokiller arrived, I was immediately aware of why people rave about WA GBBs. The Prokiller truly is a beast of a gun. While the slide slide and grip (including the trigger and trigger guard) are composed of ABS, the lower rail and trigger/safety/fire selector assembly are made of metal. This adds a good bit of weight to the gun and also balances it perfect for my hand. I don't care for the grips too much. The raised pyramid affect tends to snag the fabric of my gloves (just some cheap SpandoFlage gloves), and doesn't feel all
that great when bare handed. It does, however, make it so that the gun doesn't slip or move around during firing.

After looking over the gun for quite some time I was almost convinced that the slide was metal. After much consideration and disassembly I did finally realize that it is indeed ABS, but it looks and feels incredibly robust. On the left side of the gun, the slide bears the Prokiller Mark II markings, and on the right it has "Infinity .45 ACP" on the bolt cover and "Law Enforcement Only" on the slide. The metal lower frame also has the SV Logo to the upper left of the trigger assembly.

Left side: Prokiller Mark II
Western Arms Factory Right side: Law Enforcement Only
Infinity .45 ACP & the SV Logo and WA ASGK stamp on the metal lower frame.

Unfortunately the gun comes with standard front and rear sights. I say unfortunately cause the rear sights can't be adjusted all that much. I'll probably look at replace these with a Bo-mar Rear Sight in the future (probably when I get around to adding a metal slide).

The Prokiller MK II has the added benefit of Full and Semi Auto over it's SV Infinity 5" Semi-Only counterpart. This functionality was one of the main reasons why I chose to go with the Prokiller MK II. I have owned a Glock 17, and a friend had a Glock 18, and I wasn't overly impressed with them. I have always been less then impressed with the G18c; including its track record and their fickleness. Not to mention they just seemed a bit too small to me. I guess I'm not a Glock person. I'm hoping the Prokiller doesn't succumb to the same problems as other full auto GBBs. When fired on Semi-Auto the blowback is very nice and crisp. And when fired on Full Auto, the blowback is just as nice. It doesn't cycle quite as fast as the 3.9" SV Infinity but that was to be expected with the larger and heavier slide. The fire selection switch is located on the right side of the gun, just above your thumb. The placement stuck me as being pretty cool, as it tends to look just like a gun that has dovetail safety. The downside to this is that if you don't keep a solid grip during firing the recoil can (and I have) cause you to push the selector switch from full to semi while firing the gun. The safety is on the left side of the gun, just opposite of the fire select switch, and only functions when the hammer is cocked back.

Fire Selection
Up = Semi
Down = Full (shown) Safety

Disassembly of the gun is rather quick (well, slide disassembly at least). Just pull the slide back to free up the slide catch and push the catch out (make sure the mag is not in the gun). Once the slide catch has been removed, just push the slide assembly forward and off it slides right off. To remove the slide internals just push the barrel assembly forward a little to expose both the outer barrel and the recoil guide rod. Unscrew both of those and gently slide the barrel assembly back being careful not to bend or let the spring pop out. At this point, just take out the spring and lift the inner barrel assembly from the slide.

The inner barrel assembly is an area that concerns me to some degree. The threaded end that the outer barrel connects to is just plastic and from the few times that I have disassembled this gun, it already shows a good bit of wear and tear. Also make sure that you don't mis-thread the barrel on or you'll end up stripping the threads, which also seems to be happening a little even when threaded on correctly.

Inner barrel assembly threads

The Prokiller Mark II does have an adjustable hopup, and while that may cause several GBB purists to cringe, I think it is pretty cool. After all, I doubt this piece was designed for accuracy or target shooting. As a skirmish worthy GBB, the adjustable hopup is a welcome addition. Adjustment of the hopup on the other hand is definitely not cool. In order to adjust the hopup, you must disassemble the slide as mentioned above. On the back of the inner barrel assembly, there is a very small hole in which you insert a small allen wrench (included with the gun) in and adjust the hopup. One thing I noticed is that the hopup adjustment is not overly touchy (as opposed to what I've read concerning other WA guns). Also something that struck me as odd and maybe some of the other GBB Experts out there can shed some light on this, is that the Inner Barrel seems to have 2 HopUps. The lower part of the inner barrel looks to have what appears to be a fixed hopup, while on the other side of the inner barrel is the location of the adjustable hopup. I tried to get a decent picture that would show it, but I couldn't get any of them to turn out. Maybe I'm just seeing things? (Anyone who can answer this definitively, please post in the forum below and I'll be sure to edit this section). Maybe if I take the entire inner barrel assembly apart I'd be able to tell for sure, but I haven't attempted complete disassembly at this point. Nor do I really want to unless it's completely necessary - which it's not right now. As it stands using .2g BBs (and HFC134a) I didn't have to adjust the HopUp at all and was able to get fairly decent accuracy in regards to hitting a man size target.


HopUp Adjustment Hole

The bolt assembly in the rear of the slide is also an area that I didn't attempt to disassemble. Several springs and parts are there that I don't want to mess with at this point. That can wait until later when it's necessary or when I get to the metal slide. As you can see by picture, there is already a bit of wear showing up on the bottom of the assembly and I haven't used the gun all that much (maybe 10 - 12 mags total). This section is also where a lot of the slide weight comes from as from what I can tell, the whole (or at least a majority of it) thing is metal.

Slide - Rear Internals Rear Hammer Assembly

The magazine for the Prokiller is WA's current R-Type Double Stack Mag. The standard magazine holds 31 rounds, which is a pretty good amount of ammo for a backup. A 52 round hicap is also available, but will extend a good bit out from the base of the grip. I don't really care for the look of that, so I doubt if I'll ever have one of them. The gas fill valve is at the base of the magazine, and of course make sure to push the valve-lock down to free up the gas release button.

Full Mag
(31 Rounds) Double Stacking BBs Valve Lock and
Gas Release

On to performance and the one thing that I was not impressed with right out of box. As with all WA GBBs it is highly recommended that you use HFC134a gas as the slide and internals aren't made to support the use of the stronger HFC22 Green Gas. Using HFC 134a I was a bit disappointed. The slide movement and recoil of the gun when fired seemed a bit anemic and weak, quite unimpressive for what I was expecting from a gun that looks and feels like a beast. (Ever honk the horn of a truck or SUV only to hear a pathetic little squeak and wonder why they took the horn out of a Geo and didn't use a larger more ominous horn? That's sort of the same feeling.) Of course, I couldn't stand it and just had to try it out with something a bit more powerful. Having a can of Green Gas I promptly filled the mag and hoped for a more impressive report. Luckily, I got just what I wanted. The recoil, report, and blowback was much much stronger and much more impressive then the previous use with HFC 134a. At this point, I started looking around and trying to find out just how back it would be using the more powerful gas instead of what was recommended. As usual I found several differing opinions. From reports of other users who have been using HFC 22 exclusively in their WA guns with no ill affects, to others that have blown internal components from using HFC 22. At this point I even tried using a combination of each gas. Filling the mag a little with 134a and then add a bit of Green Gas after it. The mixture of gasses didn't exhibit a remarkable impact and in fact managed to be quite inconsistent with some shots having more power then others. Due to the inconsistency, I have chosen to just go ahead and use Green Gas, and while I know it's not "recommended", I'll just be content to use it as is and at least prepare myself until such a time as something does to go wrong. When I'll take the steps and upgrade whatever is needed at that time.

I managed to forget to chrono the gun with HFC134a, but did get it chrono'd with HFC 22. With HFC 22 (Green Gas) and .2g TM BBs, the gun performed at an impressive 331 FPS (High of 340 FPS, low of 318 FPS). As soon as I get my new chrono in (about two weeks) I will chrono the gun again and update these readings (or lack thereof).

From my experience with the WA Prokiller Mark II so far, I am quite pleased and impressed. As mentioned the gun is rather large, which was a good thing for me; but may prove to be a bit bulky or cumbersome for some users.

I have now seen first hand why the WA line of GBBs receives as much praise as it does. This gun has earned a permanent spot as my sidearm. Now to get a good thigh holster or cross draw vest.. and a slew of other accessories. Now comes the joy of customizing the gun and fitting it in with the rest of you gear. The fun never ends. Purchase yours overseas in Hong Kong or in the US at AirSplat.com