I was bored one day then thought of an easy way to build a compact springer repeater pistol that uses a magazine. The magazine release is fairly simple hard to explain but if you've owned an airsoft pistol you'll understand. The design will be placed inside a m1911 toy cap pistol (not to scale).

1. Orange bit with aqua blue bbs is magazine
2. Spring Plunger and trigger is self explantory
3. Grey dot is an O-ring for hop-up.
But I have one major problem in this design and it is the breech open / close because if air is blasted out of the piston it won't go directly out of the barrel due to friction if you know what I mean.
I can easily build a breech but I just want to have one cock per shot, not one cock, one breech pull per shot. Anyone have any ideas of where I pull the plunger and at the same time the breech opens then closes?
P.S Plunger Spring Information:
Length - 70mm (2.75")
Outside Diametre - 16mm (5/8")
Wire Diametre - 1.40mm
Max Compression Length - 19.6mm