Recently I upgraded my M4 and was looking to hit a muzzle velocity of about 400 feet per second. In doing this I knew that I would need to upgrade not only the spring, but some of the other internals as well to maintain reliability. Being that I knew putting in a bearing piston head often increases fps slightly (due to greater compression of the spring), I opted for the silent piston & cylinder head set from Element. Often, using a silent setup will reduce sound (to some minor extent), and reduce velocity by about 2%, so I figured this would offset the fps increase induced by the spring and bearings slightly.
The cylinder head is machined from what appears to be brass. The machine work was excellent and the o-ring on it appeared to be good quality with no variations of thickness or ragged edges. The back of the cylinder head is concave, so as to receive the convex piston head. There is also a foam rubber pad that goes around the surface to pad the piston head on impact.
The piston head is also well constructed from plastic with a very thick o-ring. The bearings appear to be very good quality and slide easily in their track.
After installing this I took it down to Airsoft Atlanta, where it chrono’d about 415 fps (with other upgrades also done). The compression didn’t seem great when I tested it by hand, but after chronoing the gun, it must be really good.
As far as sound goes… I really don’t know why they are called “silent”, as they still are anything but. The sound of the piston head hitting the cylinder has changed to more of a “thunk” than a “thack” but it’s still noticeable. If you’re looking to make your gun quieter this is not going to do much.
The cylinder head sealed really well. In fact the tolerances were so tight, I had to lube up the cylinder head before sliding it in the cylinder so that the o-ring wouldn’t deform or tear.
I’ve put a few thousand rounds through it, and everything is still in excellent condition and I expect that these parts should last plenty long enough.
When looking at the ratio of price to performance, the Element Silent Piston & Cylinder Heads are an excellent value. Even though they are really inexpensive, they work better than many of the other brands out there, and at a fraction of the cost. The only downfall is that I’ve only been able to find them at GunnerAirsoft.com . Nothing against Gunner, but I can’t find anyone else selling this stuff. I picked mine up for $15 plus shipping. Of course, shipping comes out of Hong Kong, so you’ll be paying a price for shipping, but if you’re ordering other things at the same time, it’s not a big deal.
Overall I’d expect these parts to last as long as anything made by the competition or maybe even longer. I’d recommend this to anyone looking for an upgrade or replacing a broken part!