Custom airsoft

[fillan]

I am beginning to go deeper down the rabbit hole of airsoft. I have had similar "technical" interests before, and one thing I always remember is how complicated everything is, especially if you want something top tier. What i refer to this time is general tuning and customization of airsoft rifles. So, my question is, are there any big/reputable and good tuners for airsoft in EU where you can send your weapon and they can upgrade them for you? If yes, do anyone have any recommendations? It would be much appreciated

fillan

[TheFull9]

Which country are you in?  This is primarily a UK forum and perhaps the most well known airsoft techy type guy here states on his site that he only takes UK customers (one example).