lowering FPS

[bangyourdead]

Ok guys,


Took my toy out to play yesterday for the first time since i got it , G&P M4 CQB lovely wee things . but site that i went to chrono'd it and it was sitting at 356fps. site limit being 350 so gun was a no go. so i need to try lower the fps . Any help would be appreciatted.

Also my mag catch is fooked, wouldnt house and my mags at all. not impressed. any techies that can help.

[Lukey b]

Re: lowering FPS

What spring are you using? Just put about 2-3000 rounds through it, that should lower it, if it's new that is. On the mag catch question, new mag catche's you can buy for about 5-£6.

[jagillham]

Re: lowering FPS

Send it back for the mag catch problem?

Putting a few hundred rounds through it may help.

Make sure you have the hop set right, as this will reduce a few FPS. But obviously make sure the flight path is straight still. You can't throw the hop all way on for crono, then correct in game, as that kind of behaviour gets people banned!

You could also try catching it half cycle, and keeping the spring compressed over night.

If none of that works.... good old fashioned put in a lower rated spring :D

[bangyourdead]

Re: lowering FPS

Cheers guys,


The rifle aint brand new , it was a swap i did a good while back. but as far as the internals and all tha jazz. aint got a scoobie. I aint a gun tech. know how to shoot it , make sure it hits the target and such. the mag catches and release etc im going to need to replace i think I will endeavour tomz to fire some rounds through it and try reduce the fps that way. im not sure if the lipo batt im using in it maybe kicking the fps right up. im not sure as this was first time playing with it

[grey]

Re: lowering FPS

The battery wouldn't be affecting the FPS in any way
As suggested, if the spring is new put a few thousand rounds through to let it soften up.
If after that it's still to high, before you buy a new spring try getting some sharp wire clippers or the like and snip off 1-2cm of the spring's coil, it may just do the trick.

[jagillham]

Re: lowering FPS

Battery makes no difference to FPS, it just pulls the spring back quicker, still shoots forward at same speed

Have some fun with some targets, and then see how it is later is the cheapest option! However is second hand, may well have already settled at just above 350!

A new spring is only £10 - £12. Most sites will have somebody there who will fit it for a nominal price, or a burger at lunch!

[gundude]

Re: lowering FPS

with regards to the mag catch, there should be a small screw on the mag relase button make sure that is nice and tight if its a bit loose it can make the catch a bit slack, or its just worn out so buy a new one :D

[Ells]

Re: lowering FPS

all chrono testing should be done with hop fully off. easiest thing to do would be get a lower powered spring, or clip a coil off however you could remove a tooth on the piston, switch the bearing spring guide to a non bearing one, switch from a ported to non ported cylinder.

[Fizzy]

Re: lowering FPS

Battery makes no difference to FPS, it just pulls the spring back quicker, still shoots forward at same speed

Funny you say that, but a team mate of mine has a G&P CQBR and with the battery fully charged, for the first few hundred shots, it fires a higher FPS before settling down. Go figure...

[Ells]

Re: lowering FPS

is he running a ported cylinder, could have something to do with it not being pulled back as fast?

[Fizzy]

Re: lowering FPS

is he running a ported cylinder, could have something to do with it not being pulled back as fast?

No idea, it's how it came from G&P he's never had anything done to it. I forget what FPS it's firing at but he had it chrono'd at The Mall last time we were there and it was too hot. He went on the range, put a couple of hi-caps through it and had it rechrono'd and it passed. It's always like that for the first few hundred shots on a freshly charged battery

[jagillham]

Re: lowering FPS

Friction on the hop rubber warms it, and expands slightly to reduce the FPS? Who knows?!

[grey]

Re: lowering FPS

Friction on the hop rubber warms it, and expands slightly to reduce the FPS? Who knows?!

I imagine that being the cause in some form or by some degree
After a long period of not being fired the hop rubber would 'reset' somewhat to it's default shape (i.e. it will be at it's stiffest if you haven't used it in a day or two) Every round fired will 'soften' it a bit up to a point where it will offer noticeably less resistance than at the start of the day
Just an educated guess mind