Guess ill take a look into the nozel and hop-up area.

zoop

been having a similar issue with Modify springs. tested on 4 different guns and got the same numbers..

M110 is getting 330-340 FPS, and the M120 360-370. i would like to be in the 390 range.. but i dont want to be using a M130 to do it. on their site it stats that i should be getting 360 to 390 on the M110 (110 x 3.28 = 360FPS), and that the M120 should be getting 370 to 420 FPS (120 x 3.28 = 393FPS).. now are my numbers screwed or is Modify over stating theirs?

I haven't really used Modify springs, so I couldn't say. What length inner barrel are you using?

363mm M4 length

are you using a ported Cylinder?
I was recently asked to put a 363mm inner barrel in an AEG that had a 120 Spring in it,
the 120 should have put the speed over 400 but due to the ported Cylinder its wasnt pushing enough air volume to achieve the top speed.
I put in a non port cylinder and the speed jumped to 440 FPS, I dropped in a Modify 110 and the speed hovers at 390 FPS.

plus with the lighter spring the entire system runs faster and The battery lasts longer.

i tried 5 different cylinders, ported and non-ported.. kinda getting pissed off at this.. it can't be a bad air seal on 4 different guns.. when i plug the end of the barrel that piston stops before passing the midway point of the cylinder.

another little trick on some ported piston heads is to open the holes up a little,
namely I worked on a mp5 that had a stock ported piston head but the ports were TINY.
I used a hobby stlye 1mm finger drill and made the ports larger,
now with the added prressure on the oring to the cylinder wall it would hit compression faster thus more air volume to push the bb..

I am sure you have replaced it (with 12 pages you must have replaced it) but check the Oring, if its to strong it takes alot before it will compress against the cylinder wall.

Im a little late to this thread so forgive me if you have tried these methods already
good luck
SV

well like i said in the post above, there is no compression issue, the pistol stops and doesnt move forward if i plug the end of the barrel with my thumb. the ports on these cylinders are fairly large, easily 1/4 inch diameter, and 1/2 long. i also checked to make sure the piston sides were not scraping the sides of the gearbox. with no spring the piston slides freely.

hi there
i did a little test last night.
1 quailty oring vs a stock hard rubber one.
I found that the quality oring hit hard compression as soon as it passes the end of the cylinder port, BUT a cheaper one moves almost a 1/2' AFTER the end of the port before it hits full compression.

so although it has full compression its still looses a little of the available air volume to force the oring to the cylinder wall..

Food for thought.
it would suck if all this was down to an oring but as you mention you have no leaks
its the only component that can have full pressure and still cause headaches.

so it might be a oring (hard rubber vs softer rubber)

I had similar problems with springs. Only promised results i`we got were with Madbull 110 and Element 125. Around 10 other springs from various sources and manufacturers were not as labeled. You can sometimes see that (example, don`t quote me) difference between let`s say 90 and 100 is only length. Fps result is of course almost the same because length does not equal power. I see this a lot, one wire thickness for 3 different springs, and then bigger gauge wire for 2 next springs....and so on.

I tried with Guarder and have mixed results. I bought 120 to 140 and then went with trial and error. I got them at ebay friom HK, so no guarantee they are real Guarder. 120 was 385fps at best. 130 was 440fps. Wire on 120 isn`t thick. Rof was almost the same as with stock 100m/s spring, where 130 couldn`t cycle with stock gears, battery&motor. So please no BS about compression problems and bad matched components. At first I fell for this crap and opened GB&gun 60 times, swapping components one by one. It was always the same until I replaced the spring. From then I never again doubt compression when I get weird results from new spring.

There is a lot of BS with spring manufacturers and people on internet. I have a feeling that a lot of people compete and try to show how good of a tech they are with insane claims. How can people have 130m/s with 110m/s spring? :banghead: Whether they went very wrong at the factory or someone is Chuck Norris himself. As I`we seen 120m/s (400fps) is breaking point. Some manufacturers have 120 wire in smaller gauge and are overrated, some make 120 thicker and are OK or underrated.

I advise buying springs from local retail and keeping the receipt or buy range of 3 springs from same manufacturer online. Price should be the same. And price doesn`t equal quality. My most expensive spring was 20+usd Deepfire spring bougt from local retail, it made 370fps (rated 130m/s) and is now paperweight, on the other hand I have Element 125ST which was 3usd at Ehobby and performs flawlessly.

i got to test the spring from the P90 im doing work on in my 416.. got almost 460FPS put of it which is equivalent to an M140. even on my set up with torque up gears, magnum motor and 11.1v Lipo, it was straining to pull it.

A spring pulling that type of velocity would actually need second level torque gears. First level torque up gears are only good for 380-440fps.