Smith & Wesson 6906, Mainspring Plunger, Stainless, Used, Excellent $15.00 Excellent condition, used stainless steel mainspring plunger, for a Smith and Wesson 6906. In stock Smith & Wesson 6906, Mainspring Plunger, Stainless, Used, Excellent quantity Add to cart Category: Smith & Wesson Related products Smith & Wesson M&P 9mm .40/.357 Recoil Spring 14lb. $14.97 S&W 39/439/3904 series XP magazine springs 3 pak $34.97