Echo 1 m28 project + piston mod

Hey guys I have been talking to Dragon64, reading his posts watching his videos and slowly but surely tuning my rifle. I figured I would post up the progress of my rifle thus far and I also wanted to post a piston mod that I stumbled upon earlier this week.
I am not new to the sport but I am new to modding BASRs and so far it has been an interesting and sometimes annoying journey. Real quick info on the gun I bought it used several months ago, it came with a masamune vsr-10 barrel, metal spring guide, element 145 spring, Harris Bi-pod and a madbull barrel extension.
I have since teflon modded the cylinder head, teflon taped the hop up rubber, installed 35mm film canister shim to the cylinder, edged the sears (started slam firing this repaired it for now as I await my sear set) and I modded the piston o-ring to provide better compression.
At the moment I can hit a torso sized target out to 250 feet with washed madbull .3gram bbs ( just ordered some .4 gram javelins)

The piston mod
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Anyone who has opened their cylinder unit in the m28 will have noticed the o-ring on the piston and how loose and sloppy it fit and subsequently inside the cylinder their was a loss of compression.
I used Dragon64's method of putting teflon tape in the groove to take up the slack and provide a better seal, but after a little use I opened up the cylinder and saw that the tape had been removed. At a quick glance the groove looked similar in diameter to my faucet, so I grabbed one of the extra o-rings I have laying around for that and put it on, it fit perfectly but still didn't seem like it would reach the cylinder walls. So I then slipped the stock o-ring over my faucet o-ring and voila a nice tight fit that seems to give optimal compression. Maybe I could use a fatter faucet o-ring but for now these seem to work great.
I don't have a way of measuring the diameter with the new o-ring set up but I will figure that out in the near future. Also I am attending an event and will be able to post up the fps results when I can use a chronograph. I might try and do a before o-ring install and after to get a real idea of any improvements.
My range seems to have increased some along with fps but again that is just eyeballing it. Also I will note the sound the gun makes upon firing now leads me to believe it has some sort of boost in power.

I will post up pics tonight and let everyone know the type or rather size of the o-ring I used.
I would like to thank dragon64 for his extensive work on the echo 1 m28 and his input to me thus far without which I would have a really nice wall hanging m28 instead of the bb Beast it is becoming. :shot:
if anybody has any input or suggestions to my upgrades lay it out here I would appreciate any input.