Why do people need MS120 springs?
 

I can't even keep any of my AEGS firing under 400fps with a MS110.

http://www.airsoftcanada.com/images/...n_banghead.gif

So buy a systema M100 lol

I have a prometheus ms120sp spring in my XM21. It shoots bang on 445fps and it semi-only. So that spring works well for a designated marksman rifle, but yeah it would be too hot for a full auto rifle.

i use a 120 spring in windy days with heavy bbs, or for kalona games. but a pro win will take that abuse no prob.

I have a MS120... havnt chronied in awhile but the last time I did it was 360 with .20's with my set up, im sure its plenty more with the 590 tightbore over my 455 length.

Rememeber, in some countries, field limits are a lot higher than our 400fps or non-existent.

apparantly god wants you to use a m100

What do you mean apparently? Read the second post, it's not apparent, its definite lol

I had one for a day or so in my MP5SD, and I was getting an easy 435fps. One should be cautious towards Madbull springs as well, I currently have a Madbull 110 in my MP5SD, and I'm borderline limit, 390-406fps. Pretty sure I'll put the 110 spring in I had tried before that, only got 350fps out of it, but I prefer that range than a 400fps set up anyways (less apologizing to people I shoot).

What you were getting in your mp5 sounds right Mike, most likely the extra barrel length that was getting me close to limits.

I have an ms100sp in my AK74 and it is shooting 370ish, perfect I'd say for field use.

Suggest you check your setup there bud, sounds like your AEG is screaming "I has airleak?" ;)

yah, 380 is a nice ballence between distance and longjevity(spelling)

I wrote that because I just installed a prometheus ms110 in a stock TM AUG and it shots an average of 415fps. While Illusion's chart rates it at 385 fps on a fully upgraded P90. Others, like ehobby, rates it even lower than that (360fps).

I had similar results on my G36 with the same ms110 spring, but it had a tight bore installed, a bearing spring guide and guarder nozzle to explain the extra fps.

Maybe that one spring is stronger than it should be, but I'm also having trouble with a prometheus ms90 which makes my CQB AEG shoots at 355 fps instead of an expected 315-335 fps.

First of all, have you ever read the ratings on ANY springs on ehobby? They're ALL way off lol
Different guns will shoot at different FPS, but you may have received a mispackaged spring. I ordered an MS100 and got an MS90 in an MS100 package.

Or perhaps prometheus is having QC issues. Anyone who has been around for awhile will remember the whole PDI spring QC debacle, this could be another manufacturer having issues.

In fact, this gives me an idea.....

http://www.airsoftcanada.com/showthread.php?t=53991

Blasphemy! lol
Prometheus used to color code their springs to prevent such things from happening. I have no idea why they would change their mind seeing as the paint flecks coming off the spring are no threat to good upgrade parts.