Best drop-in piston for VFC gear box
 

I replaced a few VFC polycarbonate pistons on my VFC gear box but although they good factory fit they break at the worse time, so I switched to a Madbull PX piston and found the PX to bind. I modified the rail area but still not as smooth as the VFC poly ones.

Are there other drop-in pistons that work as is in a VFC gear box?

I installed a Lonex Extreme Toughness Piston from Stealth's store, no issues. You will need to swiss cheese the piston though, they are "Tough" and heavier than normal. Awesome pistons that will not break.

I typically use SHS 15 or 14 tooth with no issues.

I am going to get the SHS. I don't want to waste time swiss cheesing.

I have used the modify quantum piston as well as the madbull zombie green one with no problems

Swiss cheesing is NOT necessary, the SHS piston is pretty much just as heavy as the Lonex.

I have an shs in mine vfc scar h. Workin good so far. Also make sure your AOE is correct for maximum piston life.

The VFC polycarbonate pistons just breaks under normal use. AOE was good on those but they still failed.

Before you guys go buck-wild on SHS pistons, you might want to check this out:
SCs Top Tips - Piston Check - YouTube

http://www.airsoftcanada.com/showthread.php?t=145562

Ya those clear pistons suck ass.
Ya i have an older version

Someone also measured the piston wall to be inconsistent on some shs pistons as well, with one side being thicker than the other side along the body.. this probably won't affect anything and you probably won't notice it with the naked eye, but having the spring cavity somewhat off center of the piston body might have a bad effect on piston return time or spring behavior because the spring may not be perfectly aligned. BUT... I doubt it's off enough to do anything significant since the spring has a tendency to shift around a bit off the centerline as it moves anyways.

The 15Ts are still good pistons for the price though.

Swiss cheesing is not necessary... but has a number of benefits to doing it, especially on heavier piston assemblies. A lighter piston is also quieter... less mass smashing into the cylinder head means less noise.

Nice video showing how to check a piston before using it.

You held up the Lonex piston but didn't check it in the video. Are all your Lonex piston inventory tested before shipping out to avoid defective returns?

No, we don't test each Lonex piston exhaustively before shipping out. Historically though, Lonex has had far better QC than any ACM company.

That having been said, most of the parts we retail pass through our workbench on a near-everyday basis when doing custom builds or maintenance so if there was a problem, it would be caught fairly early on. And yes, if you purchase Lonex parts from us and it is indeed defective - it's fully warrantied and the issue communicated to Lonex ASAP so that it does not affect future units. We have this feedback loop with most of the brands we carry (even SHS). Because let's face it - crappy parts floating around the marketplace doesn't do anybody any good.