Transfer port size !

[Lol Moore]

Been working on this idea for the last month with some interesting results. Still work in progress as I have still to get through various combinations of length/diameter and shape of 'rods' that enter the port. Using a nose extension with 4mm hole in center to accept threaded rods. My TP is 3.9mm dia and initially started using M4 nylon bolts reduced to 2mm for fear of a nasty thwack and one knacked compression tube. Am confidently using M4 brass bolts now and have had them full length of transfer port at 3.4mm in dia.
One reason I wanted to do this was to try and work out where the piston stops and hence cylinder gap. Another reason was to see if I could eliminate bounce on ultra light pistons. Results thus far indicate, on my TX, the piston stops somewhere around 1.8 to 3 mm but need to do further tests. Also want to try with different strokes and piston weights - so many variables! One 'rod' I tried changed my aim points quite substantially at the longer ranges, accuracy bombed after about 30 yds so shape is another headache!
Anyway, it's all fun and keeps me busy when the telly is crap or kids/wife doing my head in!

Another concept (though more complicated) in conjuction with the inserted barrel idea of Tony L (Can a break barrel ever be as efficient as a sliding breech springer) is to have a piston with a recess in the end which passes over the barrel which is inserted through the cylinder end wall, as the piston aproches the end of the travel it seals on the barrel outer thus creating a toroidal area of trapped air between the barrel outer and the cylinder walls/end to act as a buffer

It may be possible to set so as to stop bounce back and slow the piston relatively gradually, it could also mean that as the pellet is travelling up the barrel the air behind it is trapped though this may be a disadvantage as there may not be enough energy to keep it accelerating?

all my thinking is currently conceptual as i really dont want to do any maths I am not being paid to do