Lowering FPS

[Vulcan Raven]

My G&P M4A1 is currently firing at approx 360fps, however my local skirmish site won't allow anything above 350fps so how can I go about lowering it?

[dfrear]

Re: Lowering FPS

Im in roughly the same boat at 370fps with a G&P box at the moment, easiest way is to just replace the spring with a weaker one.

[Vulcan Raven]

Re: Lowering FPS

What spring would I need to lower it? I'm thinking to lower it to around 330 so I can also use it at the mall.

[No1_sonuk]

Re: Lowering FPS

Theoretically, a 1J spring should give 328fps. What it would actually give is entirely dependent on your setup.

[Panoptes]

Re: Lowering FPS

You could take the spring out and carefully snip a coil off. One at a time will bring it down in stages.

[dfrear]

Re: Lowering FPS

I'm going with a Guarder SP90. With regard to snipping coils off, be careful which end you do it at - I had a few issues with the spring coming "round" the end of the spring guide as normally you have that extra coil very close to the final coil to stop such occurances

[Vulcan Raven]

Re: Lowering FPS

Ok I'm going to pick up an M100 spring as it gives between 300-330fps, only problem is I have never opened up an AEG before.

Will it be simple enough to do and change the spring myself?

[whiteman]

Re: Lowering FPS

http://www.airsoftcanada.com/SpringChart.php
http://www.youtube.com/watch?v=TqEUdrWElEY

[HuntR]

Re: Lowering FPS

If you only want to lose 10 fps you can usually do this by leaving your rifle compressed over a few days. To do this fire on full auto for a little bit and then disconnect the battery and leave it. Or you can half pull on semi and do it that way. However. As you said it's firing approx 360 is this a guesstimation. Or numbers got from the internet. If it is, set your hop unit properly and you'll be shooting closer to 340 than 360. Most sites these days chrono with your hop on, but be careful you don't set too much hop as they'll think your cheating the chrono

[Vulcan Raven]

Re: Lowering FPS

It was clocking over 360 whilst I had my hop-up adjusted. I'll try the method you mentioned with compressing the spring and see if it makes a difference

[screwdriver]

Re: Lowering FPS

go for the 1j or m90, m100 could be to close to the mark if you hop has a very goo air seal

[Vulcan Raven]

Re: Lowering FPS

Our site limit is 350fps so the M100 should be fine.

[Vulcan Raven]

Re: Lowering FPS

If you only want to lose 10 fps you can usually do this by leaving your rifle compressed over a few days. To do this fire on full auto for a little bit and then disconnect the battery and leave it. Or you can half pull on semi and do it that way. However. As you said it's firing approx 360 is this a guesstimation. Or numbers got from the internet. If it is, set your hop unit properly and you'll be shooting closer to 340 than 360. Most sites these days chrono with your hop on, but be careful you don't set too much hop as they'll think your cheating the chrono

I've tried your method although I'm not sure if it's worked in terms of compressing the spring. Half pull on semi seems to not do anything as I'd have to fire an actual shot for the spring to compress so I've tried firing full auto and quickly detaching the battery.

[HuntR]

Re: Lowering FPS

Half pulling the trigger means no shot has been made, that's the whole point of it. You want to catch it half way through it's cycle so as the spring is then compressed. The full auto does the trick just as good though

[Vulcan Raven]

Re: Lowering FPS

Half pulling the trigger means no shot has been made, that's the whole point of it. You want to catch it half way through it's cycle so as the spring is then compressed. The full auto does the trick just as good though

I thought that wouldn't apply to an AEG in terms of nothing is actually happening internally until you fully pull the trigger and all the mechanisms kick in.