Which Mp5 Spring

[50 Cal]

Hi all, I have a jg mp5a4 which cronos at 220 fps I'm thinking of upgrading the spring could someone tell me which spring I would need, its a v2 gearbox and had no other upgrades.... many thanks 50 cal

[The Keeper of Secrets]

Re: Which Mp5 Spring

It depends on what your target FPS is. Please refer to the tech sticky. However I would very much doubt the Mp5 is in good working order if it's at 220fps. A new spring would do the job, but it would have to be quite high to compensate for the air leak you appear to have, and would thus add a fair bit of strain to the gearbox. A far better way of doing it would be a degunk and general gearbox service, paying particular attention to the airseal parts.

[bobtuskins]

Re: Which Mp5 Spring

I'm surprised that a JG comes shooting that low... Usually they chrono upwards of 350.
Regardless, to boost the FPS up you'll want at least a 1J or an M100. This should hopefully bring the FPS in the 320-340 range, depending on how much air is leaking out, which is what I suspect given the low FPS of the stock spring.

EDIT: KoS beat me to it. Basically, what he says.