If the recoil of the stock GBLS GDR-15 AEG is not enough for you, there is an upgrade Steel bolt to give you more kick. The Besta Airsoft Team takes a look at this... "Review of the new GBLS GDR 15 steel bolt, a product released a few months go that gives the GDR 15 more recoil, ideal for those players that want more realism during gameplay."