M97 Internal upgrades

Has anyone modded the internals for the M97? I have a whole heap of external mods and a hop up on the way in the post to make it look sick, was just wondering if anyone has played around with springs and such and if they came across any problems. It shoots pretty hard stock, I’m a little worried about putting a bigger spring in it and breaking it.

Hey mate ive put in an m4 1.4mm uneven spring and lubed it up real good cause it was pretty dry inside. Next upgrade is to change the piston head with an o ring type

Sweet man, did the uneven spring make a big difference? I was thinking of putting a 1.5mm spring in. I watched a video of the M97 being dismantled and was impressed with the stock alloy barrel and 1.4mm spring. The guy said the compression on the piston was pretty good, but I’d definitely be interested in an upgraded piston if they’re around! I’m pretty new to the modding scene so I have a pretty limited knowledge of whats about.