Variation in FPS in AEGs

[demon.b]

I've got two CA G36, a C and a K, one gearbox is factory standard, the other has a slightly uprated spring. Both guns produce a chrono'd variation of 8 fps shot to shot.

I'd like to know if this variation can be reduced and what it would involve to see if it's worth the time and money, or if it's an acceptable variation.

I've searched up a useful guide on checking compression, which includes some advice on rectifying any problems, post #7 in here:

http://www.arniesairsoft.co.uk/forums/inde...showtopic=93008

Anyone able to add anything?

Also would a bearing spring guide help? My thinking being that it will even out any variation when the spring twists as it compresses. Is my idea along the right lines, or a load of tosh?

I also searched up a comment that a bearing spring guide will add approx 20 fps, is this a reliable figure?

Apologies if this has been covered, if anyone has any links that cover this it would be appreciated, after 3 hours of searching I'm starting to twitch. My search-fu is weak.

 

[Tom Andrews]

You are correct that a spring guide may help as you correctly surmised. 8 fps varience isn't unusual, but it depends on the spring. A 8fps variance on a 360 fps gun is not as bad as on a 280 gun.

 

I would expect that a range of 4 fps in more usual and + or - 1 fps possible.

 

- At least that is what a stock Chinese clone AK74 puts out on a chrono.

[Stealthbomber]

Bearing spring guide might help a bit. I doubt it'll add 20fps. maybe 10.

 

Most variations are due to air leaks in the hop-up. Curing air leaks is just a question of having a bunch of nozzles to try and having the patience to try them all out and see if one improves things.

[T.P.Evan]

In your G36 with the slightly upgraded gearbox, who's make of spring would you happen to be using and what rating is it?

[demon.b]

In your G36 with the slightly upgraded gearbox, who's make of spring would you happen to be using and what rating is it?

<{POST_SNAPBACK}>

It's a Systema M100, was fitted as part of a deal when I bought the gun.

Currently averages 324 fps with .2 bbs.

[Prolific]

I think your variation is fine. Infact it's quite small really.

 

You've only got 8 fps of variation at 324fps average. Your looking at plus or minus 2.5% in fps, thats quite good. Could be smaller, but you wouldn't notice it if it was anyway.

 

In some senses, variation can be good, especially if you use full auto fire a lot, it gives you a slightly more disperesed spread of pellets.

[T.P.Evan]

It's a Systema M100, was fitted as part of a deal when I bought the gun.

Currently averages 324 fps with .2 bbs.

<{POST_SNAPBACK}>

 

I have heard of pretty big variations in velocity with Systema springs. Someone on Airsoft Ohio did an experiment with several Systema springs and found big variations in velocity with springs of the same rating. Then he tried a couple of Guarder springs of the same rating and got consistent results with both.

 

Conclusion:

Guarder springs hold a more consistent velocity than Systema springs, which is making me think that your velocity variation may have to do with the Systema spring.