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hot cqb aeg

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hi guys, got a seriously hot aeg, its hitting 390 on my chrono. which for a cqb is taking the mickey a bit.


anyway was wondering what spring i would need to get it down to 350? (asuming changing spring is easiest way?)



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m stands for meters per second. 90m/s is about 300fps m100 is about 340-350 but if its cqb get a m90

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FPS depends not just on your spring but also on how good your level of compression is. If you want to save some money you can try cutting a couple of the coils off or just buy a M90 or M100.

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As Trigger said - very difficult to call


Springs vary from manufacture for a start - often springs can be a bit over their rating


length of barrel can increase fps - joule creep on longer barrels plus tbb can knock it up a bit further

a mp5k 110/140mm barrel will probably have m110 to equal a 363mm on m100

plus some longer barrels like AK's 455mm to R85's with 510mm+ may have a m90 to equal an aprox 340fps - ish


The " ish " factor comes into play even more variables even if all guns mentioned have 101% seals and compression.....


An ultra light piston Vs heavier piston "may" increase fps very slightly from piston returning a bit faster in theory


But more so if AoE is corrected then 10fps drop aprox will take place


if bearing spring guide used and/or piston bearing bearing used - each of those factors can add on 15fps aprox


So you can see one mp5k with m100 could hit near 300 not 328fps

and another gun AK47 with bearing spring & piston spacer could hit 365fps say on the exact same spring


Sounds bollox but these examples I and others have witnessed the results so it is at best a calculated guess based upon previous builds

even then if all is perfectly sealed you get some wtf's ???


You say cqb - so gonna guess aprox 275-300 barrel - ish (do love an ish)

so my guess shs m100 to Element m105 max if correcting AoE

if still down add bearing spring guide for 15 fps more aprox


That is my rough workings out so far - still not 101% accurate due to loads of variables like I mentioned

Hope this helps - but don't sue me if I am way out

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just another thought......


if piston was full metal rack you could short stroke it a couple of teeth

this is only for sad speed freaks tbh - remove 2 teeth & AoE corrected might do the job

(can't reall short stroke full cylinder guns like ak's but medium length barrel guns can be SS carefully bit by bit)


but tbh get a m100 spring is probably quickest & easiest all round solution rather that cut off teeth n crap

(I screwed up first time around so I don't advise this - get a lower spring - job done (hopefully))


another thought - what gun ???


reason I ask is that some guns SRC JG plus a few others have that horrible 10mm alloy spring retainer clip in piston

(bloody heavy things too)

that mofo will add on a bit to spring compression - a piston tooth is 3mm so that could be like compressing spring 3 more teeth than a bare piston

In reality I'd say over half of pistons have a bearing/spacer of about 5mm inside

G&G's have a 5mm plastic spacer in them - same extra compression as a piston bearing but lighter and less prone to coming undone

(loctite threadlock is best but if you forget you will learn the hard way after a few thousand rounds)


If it has that funny alloy spring retainer spacer clip thingy bollox - then the spring will be hooked into the piston

and may need to strip piston head off to get the sod out - chuck it


then with no spacer in piston m105 me thinks should be fine and not over

AoE should be done and if down a bit add bearing spring guide


Alas this crap I'm suggesting is at very best just a guess - until you open her up you won't have much of a clue what is in there

could be a m110 hooked onto piston with alloy spring thingy

could be a very short gun with m120


TaiwanGun / Gunfire ???


m100 to m105 and perhaps bearing spring guide if needed after AoE

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its an ares m4 cqb4. its an awesome little gun tbh. annoys me coz there was a tag on trigger guard giving its velocity in mp/s, not that company i got it from told me that.

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Guarder SP's are reported to be 30fps more than other makes of springs




SHS's are more expected output spring but Guarder ones have been know to be a bit out on the rating

as for % rating - nah I give up on those ans stick with shs

or do a test comparison with a aps uar quick change aeg now


also to add even more stuff - irregular springs - tight coils at one end of spring...

if fitted incorrectly give out lower than expected results


oh yeah piece of cake this expected fps guessing malarky

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