Sadlak Industries M14 National Match Groove Gas Cylinder Piston, Titanium Nitride Coated

Sadlak Industries precision pistons are made to the exact GI specifications with all critical dimensions individually inspected.  The 420 stainless material and heat-treating operations are both certified to assure quality.  The pistons have a highly polished surfaced using a non-contact electro-polishing method that maintains tolerance on the critical diameter and does not "round-over" the edges on the grooves.  The pistons are then hard coated with a gold colored Titanium Nitride (TiN) finish.  This coating, often used on machine cutting tools, helps reduce galling and pitting and holds up better to the high heat and abrasiveness of gunpowder and primers.  The resulting effect is a smoother action an improved life of the piston and cylinder. The alteration to the pistons adds a .030/.040 wide groove running along the piston axis on the large diameter. The groove runs through the gas-port hole for the purpose of equalizing the gas pressure for a smoother more consistent action. The groove is ground to the actual GI national match drawing #9352724. The original GI drawing for the standard piston is #7267047 which does not specify a polished finish or the groove.