Candidate 2: Systema Aluminum Piston

Systema also offers a full metal piston constructed of aluminum, with the added benefit of full teflon coating of the piston. The teflon coating gives the piston a distinctive beige gray coloring as well as a relatively smooth finish. Teflon is a well known surface coating used to increase surface lubricity and reduce friction and wear. The use of teflon on a full metal piston may help to reduce sector gear wear. Interestingly, the instructions supplied with the Systema Aluminum Piston displayed the following:

"The Teflon coating on SYSTEMA Piston is free from greasing that slows the piston movement.
"Notice: Please do not lubricate the grooves on the rail guides too much. Please minimally grease the rack gears and the sector gear that bites the rack gear, with a cotton bud or such."

Systema clearly intended for the teflon coating to act as a self lubricant, thereby reducing the need for added grease which they contend will reduce the rate of fire.

While the coating appears even throughout most of the piston, there are some rough spots in the coating, especially on the guide rails. Aside from the differences in color, the Systema aluminum piston appears identical to the ICS piston in construction.

Piston: Systema Aluminum Piston Weight: 0.9oz Piston Material: aluminum Metal Teeth: all Average Barcol Hardness (piston/main teeth): 77.5 Average Barcol Hardness (tooth insert): 86.2 Tapered Lip: yes Distinguishing Feature: teflon coated body and teeth

The smooth texture of the teflon coating can be clearly seen here. There is a very slight taper to the piston barrel lip, although it can not be clearly seen in the photos.