Hey all,

I got my first AEG (hell yea!) but the thing is its an internally upgraded one with a strong spring.
So the current FPS is 440-450 with 0.2 bbs, chronod myself.. The AEG is new and not used at a skirm yet so the spring hasent set in yet.

Now on some fields for CQB there is a 340-360 FPS limit, and before going to downgrade the spring and breaking in the current spring i was wondering if it would make any difference if i would use .25 or even .30 gram bbs?
The AEG is a M4 CQB (yes with 450 fps.... i know... ) and i was wondering if it would be wise to even use .30 bbs with this AEG? (not being a sniper AEG).

Any info or advice would be much apriciated, thanks.

FPS tests should be taken with 0.2 gram BB's.
What is actually the problem is the amount of energy not the speed of the BB. Ifyou change the weight the energy remains the same, just the speed changes.

If it shoots 450 FPS "breaking in the spring" won't get you below 360 FPS.
You need to downgrade your AEG. replace the spring or mess around with cutting of a few coils of your current spring. (some people do that.) Personally I've never had to do a downgrade as I won't buy a replica that shoots to fast.

Just downgrade to a M90 srping, should work perfect for around 350 FPS.

Your internals seem to be upgraded, so they can easily handle the M90 spring.

Alright,

Thanks for all the info and help guys.

Now SlickAxe, is your choice of the M90 spring based on the thought that my AEG internals are upgraded (witch they are btw.)
Els if some one could help me make a choiche on a spring (like M90 or M100) with the help of a list on wat my upgrades are:

M130 spring
Chrome bore-up cylinder
Reinforced metal cylinder head(bore up type matched for the silent system)
Reinforced silent type piston head with Ball Bering(berings helps with smoothly rotating the spring Turing the work)
Hi-torque motor
All steel Sears are placed In steel bushings 6mm
Spring guide is standard-metal reinforced with Ball Bering so the spring will rotate smoothly
Low resistance gearbox wiring

At least these are the upgrades listed at the information page in the shop from my AEG.
I have been searching and reading and if some parts are upgraded a m100 spring could be to much and give over 360 FPS?
So i dont know enough of all the upgraded parts to deside of a M90, M95 or M100 spring will get me to 350-360 FPS?

I have been looking at an Guarder SP100 spring, as it should do 340 FPS according to a chart, is this correct or will it be a bit more due the upgrades?
Anyone could give a recommendation on spring type according to the AEG upgrades?

Just a suggestion... concider having someone do this for you.
It might cost you a few bucks but they'll have multiple springs laying around, so they can tweak until they get it right. It will also save you the trobule figiring out how to but the gearbox back to gether again.

Well i have searched for a shop that could replace the spring, but no one would do it because of the brand (P&J some sort of CYMA/DBoys rebranding by the shop). And sending it back to the shop would mean its gone for a week or 2 and shipping costs arent that litle either.

Anyways i have been looking at loads of videos on how to replace a spring and to be honest it doesnt look that complicated to me. So i am willing to give it a try myself, i just need to know wat spring to get to get the ammount of FPS i need (360) and get much more then needed els i still cant play.

I could be wrong, but isn't the standard spring used in a lot of AEG's a m100 spring? A guide to determine which spring u need could be the following :

Most springs besides PDI are rated in metres per second, so a M100 spring is 100 metres per second or 328 feet per second.

According to this "table" a m130 spring would give around 430 fps. You chrono'ed it a little higher, so by simple calculation a m90 or m100 shoúld be sufficient.

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