The Prometheus closed cylinder is type A. But the stock cylinder will be sufficient.
Regarding the stock pipe, what I do is completely tighten it first and turn it back for the correct position. It may be possible that you have a misalignment that will give the sensation of getting tight early. The rear part of the mechbox should be inside the stock pipe.
Buffer Pipe
Agree with Hazard, I do the same for mine. Yes if you don't screw it all the way in, you will have less tension in the spring. (spring guide rests on the buffer tube's internal plate)
Hop
I suppose all the measurements you're taking are with the hop set on zero?
Cylinder
Yeap, the stock one will do nicely though if you already had 91m/s stock and are performing the list of upgrades you mentioned... I'm afraid that will take you over the limit. Mine was 84m/s before all the upgrades and 96m/s after. And to top it off I'm using a 6.01 285mm inner barrel.
BB Weight
Also just checking only here but you are testing with 0.20g bb's right?
Thanks Hazard. i will use the stock cylinder and pass the one I bought onto someone with a shorter barrel, or keep in incase i decide 550 is too long. I am confident the tock pipe went in clean as it sounds like i did the same you did (tighten and then back off to align wires).
Anarchy,
All readings have been with no hop. Adding hop reduces m/s. I don't know, with the stock cylinder I was loosing 9 m/s with the longer barrel, so maybe it will all add up nice and even...although I doubt it
Will let you know how it turns out. BB is weight .20. Thanks for all your help folks.
(16-06-2009 02:51 PM)dstole Wrote: [ -> ]@ Hawk > Sure. I am probably going to get on it this Saturday as Sunday is Father's Day. Do you want to come over again? We should start early as it take a while. I will remove the ported cylinder and put the stock one back on as well as replace the spring with a SystemA M85. I will try the spring first though, then I might not have to take it entirely apart again...although maybe I should just to make sure all is well and to lock things down with some locktight (or whatever that stuff is called). What are you planning on doing Hawk?
So besides 407mm inner (already installed) I got a Type C Hard Cylinder, Ver. 2 Cylinder Head, Sealing Nozzle and KM Piston Head.
Update:
A few days ago I mailed Q to ask him if he had any springs left from the ones he mentioned in the SOPMOD disassembly guide. He said that he wasn't sure which were which, and said that he had settled on the SystemA M85. I ordered one and it arrived on Tuesday. I finally had some time today and opened things back up. I switched the cylinder back to the stock, non-ported TM cylinder and added the M85 spring (which was about 5 cm longer than the TM stock spring, but Q assured me it was fine and I could just drop it in.)
So before I started modding this evening i was getting about 84 m/s on the chrono and after the spring and cylinder reversal I am getting measurements that average around 96m/s. However, about every 12-15 shots I get one that clocks in at 101m/s. The rest usually fall between 96 and 98...Is this probably my chrono or is there something that might be causing this fluctuation?
If I can even things out at 96/97 I think I am done.
I am still not sure about the spring. Is there the possibility that an oversize (longer) spring can cause damage to the blowback and or gun itself?
Thanks, as always, for the help and advice.
Normally the fluctuations are a result of how good your seal on your gun is. The other factor is cylinder-to-barrel volume matching (which looks like you've done by going back to the non-ported stock one)
To be real safe, you wanna make sure that your gun cannot fire above the legal limit. That said, once you tune in the hop, your power will most likely drop some and take you under the limit.
As for the spring length, as long as you're not locking up it shouldn't be a problem.
Btw, which chrono are you using to measure your gun? As for me, just to give you an idea what I got when I was using the Systema M85 with everything else stock, it was clocking in at 115m/s, hence my reason for switching back to the stock spring.