TECH: HPA RIFLE BUILD

MAX AIR FORCE!

KEEPING WITH OUR THEME THIS MONTH WE THOUGHT THAT IT WOULD BE REMISS OF US NOT TO INCLUDE AN HPA SYSTEM-DRIVEN PLATFORM, AND OUR ONCE-SCEPTICAL TECH JIMMY HAS BEEN CREATING ONE OF HIS VERY OWN. DELVING INTO THE MECHANICS OF HIS CHOSEN PLATFORM AND SYSTEM HE NOW BEGINS TO DETAIL HIS VERY OWN “HPA ADVENTURE”!

Up until a few months back I had only ever been interested in AEG’s and GBB pistols and I honestly didn’t care much for anything else. My head was well and truly buried in the sand when it came to “operating systems” and looking back I rode very roughshod, not paying any attention to others and their opinions on anything; like many out there, I’d set my course and I was steering it!

This was actually a bit wrong of me if I am to be completely open and honest, because boy, was I missing out! The thought of a High-Pressure Air systems, or simply HPA as we all know it, in airsoft left a sour taste in my mouth; I believed firmly while it has its place, its place was not in airsoft and should stay very much in the paintball world, and the thought of running around with “scuba gear” as Bill so kindly calls it, “old skool fool” that he is, left me cold. I liked the freedom of a self-contained, battery-driven system, and that was an end to it!

There seems to be a lot of stigma surrounding HPA systems and the people that use them. Well, my opinion has completely changed in that I believe that HPA is a very effective way to power an airsoft rifle, specifically a good sniper platform, and let’s be fair

on this, HPA is becoming more prevalent; from an industry perspective there is no going back now and the feet of HPA system manufacturers are well and truly under the airsoft table, so deal with it!

Let me preface my personal journey into HPA though; a few months back a dear friend of mine asked if I would take a look at a couple of his HPA rifles and see if I could get them working properly. Over the course of a few weeks I learned so much about HPA, and then had the pleasure of playing using this system in the interests of testing my work for my friend, and that is when my opinion changed. I managed to trade a few old AEGs and ended up with a Double Bell “VSR” clone, which was actually quite a nice piece of kit, and for me was the first “VSR” I had seen with a real wooden stock. As with many stock bolt action airsoft rifles, while it worked okay and was pretty damn quiet it needed something more to be field effective.

I acquired a Mancraft SDIK kit which would enable me to convert the spring system into a HPA system; sadly the Double Bell turned out to have a different spec to that of a Marui VSR which was a bit disappointing as I really liked the wooden stock, so back to the drawing board. A couple of weeks later another friend of mine (yes, you Mr Seal, you beauty!) mentioned he had a Tokyo Marui VSR G Spec that he was not using and would gift it to me in return for some work which he wanted me to carry out on a few of his AEG’s.

GETTING DOWN TO IT

Great I thought, and gladly accepted the offering knowing that the Mancraft SDIK kit would fit perfectly. To my utter amazement the G Spec was dripping with aftermarket parts already, including; • Laylax barrel • Laylax barrel stabilisers • Laylex cylinder • Laylax piston • Laylax spring • Laylax spring guide • Laylax trigger group • Action Army hop unit

I honestly could not believe just how lucky I was and it was such a great gesture on his part; sometimes your friends amaze you, don’t they, and although I would carry out the work on his AEGs as discussed, this was still a very, very generous gift - sometimes our BB-chucking community is simply a wonderful thing!

With zero hesitation I got straight to work fitting the Mancraft engine; it fitted in perfectly in the G Spec and was really quite easy to fit with only one small mod needed, which was to drill a small hold for the inlet tube to feed through allowing easy connection of the air tank. Once installed into the cylinder it is just a case of feeding the airline through the trigger group where once the spring guide stopper sat slide on the brass tube which now acts as a spring guide stopper and button everything back up.

“WITH ZERO HESITATION I GOT STRAIGHT TO WORK FITTING THE MANCRAFT ENGINE; IT FITTED IN PERFECTLY IN THE G SPEC AND WAS REALLY QUITE EASY TO FIT WITH ONLY ONE SMALL MOD NEEDED, WHICH WAS TO DRILL A SMALL HOLD FOR THE INLET TUBE TO FEED THROUGH ALLOWING EASY CONNECTION OF THE AIR TANK.”

The next part was to decide where I wanted the airline to exit; I opted to have it short, exiting in front of the trigger guard. The Mancraft kit utilises a piston

and a spring still unlike other HPA engines which rely solely on air to propel the BB. The Mancraft engine operates slightly differently, so rather than the spring creating all the power, the piston itself is air driven, making it very consistent maybe not as quiet as something like a Wolverine engine, but much quieter than a spring powered version and with a foam-filled suppressor you will go unnoticed with no muzzle report .

I am a fan of a mechanical style HPA system now, as it is much simpler and easier to maintain and service, should any problems arise. Taking into consideration the fact there are very few moving parts I would be highly surprised should anything go wrong. Being HPA it is very easy to set your velocity and I am able to get it bang on and sit nicely at 500fps on a 0.20g BB; using a 0.40g BB it is hitting 353fps at 2.34J using around 100psi and will see fluctuations of +/- 3fps, but this all depends on the regulator that you are using. At present I am using a Valken Ultra Rig LPR which is proving to be very consistent with its delivery of air.

SNIPER LIFE

So this rifle would be my path into the world of “airsoft sniping” and so far I am thoroughly enjoying it and have taken to it like a duck to water! I still have a lot to learn about the true role of the sniper but it is something I am willing to learn and work at… and work HARD!

So, why HPA I hear you ask? Well, the fact of the matter is this; HPA systems have very consistent performance and are easily configurable should you need to adjust for different site limits, and due to simplistic design they offer repeatable and consistent performance. Another major benefit is the operation; an HPA-driven rifle is a lot lighter to operate than a heavy spring model, meaning less fatigue on the user and a more stable position when taking followup shots; smooth action, no needing to jerk about heaving a spring-bolt about, as an HPA-bolt just travels back and forth “into battery” like a silkysmooth thing!

As good as it seems on paper it still isn’t something that is going to make you an overnight pro; there is still a lot of fettling and testing needed for the rifle to be effective, then the rest is on the user. For instance, BB weight… after much testing I discovered that the Firefly hop rubber fitted prior to my ownership was struggling to lift a BB heavier than 0.36g. Now most snipers use a 0.40g BB and above for accuracy and flight-stability, something I was struggling with so I decided to swap out the Firefly for a Maple Leaf Autobot 70 degree rubber, but in order to do that I had to modify the barrel slightly as the Maple Leaf rubbers don’t work with bridged barrels. In order for it to fit I had to machine down the bridge.

Now with the Autobot rubber and an Omega nub the rifle is able to lift a 0.40g BB very consistently way further than before, and I can say I am effectively reaching targets out to around 80m which will far exceed most other rifles including AEG’s. I would love to get it out onto a proper range and see the 100m mark (Bill’s gas benchmark… challenge accepted!) which I know to be achievable.

There is one downside to running HPA regardless of the platform though and that is the fact you are tethered to a tank, so something I am always conscious of is the airline it can get caught up sometimes, but that is a price I’m willing to pay for performance, and honestly, it doesn’t affect my “freedom” as much as I thought it would. This project is still ongoing, and as I learn more about my chosen platform, and more about the true role of the sniper in airsoft I’ll report back.

This is but the commencement of my further journey into the world of “all things airsoft”, and as a tech the words “never stop learning” are particularly poignant. So far I have thoroughly enjoyed both creating my own HPA setup, and fielding it in game, but I know that this is just the very beginning of another exciting “airsoft journey”… watch this space!