AEG Springs in Cold Temperatures

[Mattplus]

The scenario, have got a brand new spring (I'm sure it makes a difference, what spring is used, so for the record, it's a Guarder SP110) which was installed in a new gearbox around 2 months ago and never been skirmished. The chrono results were roughly around 390FPS with .2g BBs. Testing the same gearbox about a week ago (with the same BBs), the results are this time around are roughly 350FPS.

The question(s), do springs wear in this quickly having never had more than a couple of hundred BBs through them, or is it possible that the cold temperatures Britain has been experiencing recently have caused the spring to contract enough to lower the FPS (I should mention that my wife doesn't allow me to keep my airsoft guns in the house, so they're all in the garage instead)? Many people report that springs tend to lose about 20FPS when settled, so losing 40FPS would be a significant loss- or is that still in the realm acceptability? Could it also just be in some way just a defective spring? Could it be absolutely nothing to do with spring and be to do with the air seal or some other aspect of the gearbox (maybe the cold weather has affected those too)?

There are obviously far too many variables to calculate an exact formula, but if anyone understands the physics and can jot down some maths to back up their answers, that would be great to see!

[Sir Stephen]

Re: AEG Springs in Cold Temperatures

its more likely that the rubber/air-seal components have been affected by the cold weather.

the reduction in size of the steel used in the spring, over its entire length of the wire would only be a mm at most, so when coiled, would be nothing.

[Figjam]

Re: AEG Springs in Cold Temperatures

Don't like to disagree Stephen, but I had a very similar experience with a new gun: I think many new AEGs do drop in FPS over the first few thousand BBs. My old Cyma AK dropped from around the 370 mark to 340 after shooting a few hicaps downrange and then stabilised there for a couple of years. When I've had seals go on AEGs the FPS continues to drop down to silly levels over time, and you'd expect to see poor consistency.

You hear folks talk about springs "bedding in", it's entirely possible that this is what's going on for you in my opinion. The test will be to keep watching the FPS, if it continues to drop, then, with grace, I'd defer to Sir Stephen.

As for temperature: With AEGs, cold weather shouldn't affect you more than 5-10 FPS. Its gas operated guns that get interesting in the cold. Although its interesting what Stephen says about temperature affecting seals, as I do notice on cold day's I often get a terrible first couple of shots and then things pick up and this repeats if I've spent 10 mins or so not shooting, could be the friction warming up the parts?