FOR USE IN THE GAMO VIPER AND SHADOW EXPRESS SHOTGUNS ONLY! The Viper Express has all the power and penetration needed for hunting small game and birds at medium to close range. Our precision, raised ribbed, chocked barrel yields a tight pattern of only 6 at 10 yards. The new EXP20 .22 caliber shotshell delivers a 17 grain payload of #9 shot with enough power and velocity to penetrate over 1/4 of 200 lb compressed paper board at over 10 yards. Ideal for hunting small game on the run or in the air.