Airstock Gen 2 advice.

[JBenoit]

 I like the idea of the HPA Airstock and fancy building up a semi auto AR from one. So now I am looking for a little inspiration. If you are to build up an AR from this HPA stock what bits would you use and why? Thanks

 

[proffrink]

I'm in the process of building mine around a Mancraft PDiK and MASS - just waiting for the MASS right now. I looked at the Redline Airstock gen 1 and 2, but frankly found them both to be far beyond ugly. It seems the best complete solution is an MASS with something like a Wolverine Storm (the Mancraft regulator is a bit big). I would look into their PDiK for a good semi-auto solution as mine seems to shoot very consistently (+/- 3.5 fps) from the 400-500 I've put through it this week just to test it. Also has the added benefit of being waterproof and without an FCU. The only thing I would say is the trigger break is not as clean as a GBBR, but is certainly still very good. Bear in mind that you'll get around 600-800 shots from a tank. Not sure how much higher that might be on electric solenoid, but could be just shy of 1000 I suppose if all is working well.

You also have to do some slight modification to attach the MASS - cutting down the part that the buffer tube usually attaches to. This can be done with a hacksaw and some decent files though if you don't have access to a band saw or circular saw or angle grinder or something.

I can let you know how it is when I get it.

An additional consideration is minimising air use through having a decent hop unit, bucking and also a long tight bore. I have no idea how much difference this will make, but I wanted to squeeze every shot out of the tank so went for a 6.01 PDI and a flat hop in a ProWin chamber for fairly efficient shooting. R-hop should work well too, but again I have no idea how much of a difference this might actually make.

Here it is by the way. Mancraft take so damn long to deliver that (mostly) everything else is done and waiting.

 

[JBenoit]

That is brilliant. You are right the Mancraft  stock is not half as ugly as the Redline. I like your thinking on the mechanical trigger too. Less to go wrong especially given our lovely British weather. I look forward to seeing how it goes once it's finished.

 

[proffrink]

Yeh, electric solenoid is basically foolproof at this point but I'd still make considerations based on where you think you could fit the FCU and battery for the FCU. It would be possible to fit them in a PEQ dummy on the rail or perhaps in an empty grip, but I've never thought to look into whether that was possible as I'd heard alright things about the PDiK and wanted to give it a try. Like I say, it's already in there and I'm very happy with how it performs, but I wish they'd dispatch stuff more quickly. Leave about a month between ordering and receiving your parts and make sure you pick up spare seals and elbow push fittings (for the regulator) if you go that route.

Also, this should be in the 'High Pressure Air' subforum, so I'm moving it. 'Gas Guns' is for green gas and duster powered stuff.