We had the opportunity to shoot the new for 2010 Glock GEN 4 at the SHOT Show Media day. The major changes in the Glock GEN 4 are the dual recoil spring and the ability to change the grip shape with plastic backstrap inserts that snap on and off. I was personally impressed by the recoil reduction. Glock isn’t publishing exactly how much recoil is reduced but one of the Glock employees said he had 9000 rounds through the new GEN 4 and he felt like the recoil was reduced at least 15%. I also heard numbers as high as 20% but so far I don’t know of anything official. We hope to do a full review of the Glock GEN 4 so watch our site for that in the future.