This is an intriguing design, but I have one question that I can not find addressed anywhere. How are the valve core and piston sealed? Once the piston is retracted with the trigger rod, won't the high pressure air also just escape through the center rod hole in the piston and out the back of the pi...

Regarding the famous QDV valve as outlined in this video: https://www.youtube.com/watch?v=No3nI07mlQo There is one thing I am not understanding. Once the rod is retracted and the piston valve activation begins, what prevents air from flowing through the shaft hole in the center of the piston and out...