The UTG 4 Position AR-15 stock is about 1/2" shorter than the 6 position stock. Will this difference in length of the tube make a big difference in the cycling of the bolt or cause excessive recoil due to the buffer plug "bottoming out" at the end of the tube? I like the compactness and lighter weight, but don't want to damage the buffer spring. Maybe there is still plenty of recoil room in the shorter tube. Anyone know?