MP5A4 changing the spring

[vityaz]

I have a JG version of the Marui MP5A4 and need to change the spring to downgrade the gun as its excess of my site power limits. Has anyone ever done this, and if so could they send me a link to an online exploded diagram or give me a rough idea of how its done?

[jagillham]

Re: MP5A4 changing the spring

Changing the spring is a pretty simple process, if that is all you are doing. What you'll need is a guide on how to open a V2 gearbox.

The upshot is take it out the gun. Face it pointing to the right. Then with one hand hold the top down, and the other undo all the screws. Once all the screws are out, the crucial bit is hold down the cylinder. Lift the lid up slightly, and keeping the cylinder pushed down, take off the top. This is all to stop the sping "pinging" and sending all the internals flying. Once you have done this, take out the sping, replace, and reverse the way you got in!

[johnnyj]

Re: MP5A4 changing the spring

http://www.mechbox.com/mechbox/v2-me...g-upgrade.html

all you need to know

[jagillham]

Re: MP5A4 changing the spring

If you don't feel like you want to give it a bash speak to your local site owner. Being a JG it could do with metal brushings and a regrease. Many sites will do it for free, or a small charge like £10.

[vityaz]

Re: MP5A4 changing the spring

Thanks guys, ill see how it goes. The site I play at said theyll do it for £20 but im pretty hard up, but I also dont fancy taking it up to the site in a carrier bag one day and paying even more to get it sorted!!!

[jagillham]

Re: MP5A4 changing the spring

£20 ain't a bad price. Although plently of sites would do that kind of work for free if you been a couple of times. It is a 30 second job just to do the spring. Where about you based, you might live near someone on here who could do it in return for a pint! Or maybe you could pay for postage there/back (~£10 total) and somebody on here will do it. Don't forget you'll need a spring (~£12).

Even if you take it into a million pieces, they should not charge you more for the change. A gearbox is very simple soon as you know your way round it, and can be put back in seconds.

[Caveira]

Re: MP5A4 changing the spring

I'd say it's worth using the mechbox guide and doing it yourself.

I was terrified of opening up the GB on mine the first time, but that guide made it look so simple I just got on with it. The advantage of doing it yourself is that you will learn far more about the workings of your gun than you will ever find just by reading guides and looking at diagrams.

What's the worst that can happen? You take it to pieces carefully and can't get it back together. So what? Just pay them to reassemble it for you!

[MJ Caboose2170]

Re: MP5A4 changing the spring

just wondering how much in excess of 350 is it?
my mp5sd was at 380+ when i first got it but after a few hundred rounds its down to 370 but im reay tempted to ask 1 of the guys at my site to do it

[vityaz]

Re: MP5A4 changing the spring

I may give it a go next week, see how confident I feel. I think ill have the mechbox guide playing on the computer while im doing it and pause it as I go through the stages. It actually looks pretty simple on the video. Im in Northern Ireland so I dont think I could get to anybody here to get it done! Ive got the spring already so that parts taken care of.
When it was chrono'd it was 385 fps, the sites pretty good if youre a bit over, but the boss said this was pushing it a bit!

[jagillham]

Re: MP5A4 changing the spring

You'll find the clone ones vary a lot. Many will be "hot" the over couple trips settle down.

But you doing the right thing by putting in a more reliable spring!

[Caveira]

Re: MP5A4 changing the spring

I think ill have the mechbox guide playing on the computer while im doing it and pause it as I go through the stages.

LOL

Exactly what I did the first time:D

[sheard]

Re: MP5A4 changing the spring

ask someone to chrono your gun after you've done this tough just in case its still to hot. most sites will do this for free

[vityaz]

Re: MP5A4 changing the spring

Will do, the shop I got the spring from says itll bump it down to about 312 fps, its an m95 spring if that means anything. Im getting a bit more technically minded with these things lately. Last week I stripped my AK-74 down to the gearbox in preparation for when my wooden furniture kit arrives next week! I wish they were as easy to strip as real guns! When my AKM needs any maintenance its so easy to do, I can have it apart and back together again within about 5 minutes