Works well - SADLAK National Match Gas Piston

Installed this gas piston on early '90's NM M1A. Immediately noticed a slight reduction in recoil. Groove in the piston eliminates vacuum between the piston and cylinder, making it easy to determine if piston is fouled. Only downside that might be a show stopper for some is the requirement to use match grade ammo only. Surplus ball or low power ammo is not recommended for use with this piston due to its low power. A titanium nitride coated piston without the groove is available for those who may need to shoot surplus or low power ammo.