Ares Cheytac M200 Build ... probs

[Skywalker]

Here's what I've been up to (copy pasta from write up elsewhere):

Hey all. I've got a build I've been progressing with, and I've hit a little bit of a wall. ***Also, as I've been writing this I've been doing more research, and learning things***

I have an Ares Cheytac M200, with the following mods/upgrades:

800mm 6.02 Deep Fire Inner Barrel, ER hopped (A little shorter than a "standard" ER length)

Modified Hop up unit to work with the ER hop. Window cut longer, arm flattened, and I had to move the location of the return spring so I could extend the window.

Tapped the gas mag at the bottom, which is running macro line back to a Firebase regulator (QD fitting at the regulator) There is currently a minor leak around the threading location, which I'm working to correct. It appears this leak is preventing me from running the system at more than about 85 PSI at the moment. ***Late addition, research shows me Green Gas/ Propane would be a good bit over 100 PSI. I'm going to post this anyway, for general knowledge and feedback***

Regulator is being fed with 16g Co2 threaded cartridges, specifically these: Mosa 16 Gram Threaded Co2 Cartridges (Pack of 30): Amazon.com: Industrial & Scientific

Modified the hammer spring... The spring is not fully compressed in stock operation, so I've simply spacer-ed it to compress it even more. I'm planning to make a new spring guide that would be more narrow, and accept standard (and stiffer) bolt action springs, which would be cut shorter. I'll get you guys some pictures of this since I'm sure very few of us have taken apart the gas bolt on an Ares M200 haha.

Now for the issue... Running regulator at the leak-restricted 85 PSI, I get all of 170ish FPS with a .40g bb. I've tried this with Co2 and off a friend's HPA tank. A previous chrono during the summer (~80°F) on propane before anything was modified read 515 fps with a .25g BB, which would've been close to 400 FPS with a .40g (give or take barrel creep). I guess according to the chart linked below, that would have been 120 PSI. ***Coming into writing this whole thing, I had assumed 85 PSI would have been more than propane.*** http://airsoft-innovations.com/sites...nualen_web.pdf

So with 70% of my original pressure using propane (85 PSI vs 120 PSI), I'm getting 40% of the fps? (170 FPS vs ~400 FPS) Could the new barrel be affecting anything? Barrels are the same length, I can only guess the stock one was 6.04 or 6.06.

I know there are so many variables at work here, and there is the "No duh idiot, go fix that air leak and get back to us" response ... I've just been working on this gun for so long that I needed to type things out to keep myself sane. Anyone been there before?

[Dominum]

Could anything have changed that would prevent it from releasing the pressure for less time (equivalent to a shorter poppet dwell in a P*)?

[Skywalker]

You mean the valve would be open for a shorter time? The only way I can imagine that happening would be if I was pushing a HIGHER PSI, and then the hammer would struggle to force the valve open because of the pressure. .... Thus, the hammer spring mods though.

There probably is not much to say until I can get the leak plugged properly and push 120 PSI. See what happens then...

[Dominum]

Switch back to the weaker hammer spring and see what happens at this PSI.

[Skywalker]

It was at 140fps. After that I looked into modifying the hammer