Action Army Hop-up Chamber for Tokyo Marui / Well VSR-10 Sniper Rifles

"fits great, works even better. hop effect is super consistent and eliminates the side-hopping that most stock hopup units have.

PROS
very nice anodizing
great quality
clean tight tolerances
allows the use of whatever nub you want
easy to install (installed in an mb03, no fitment issues)
precise adjustment; doesn't move once adjusted

CONS
the adjustment process is a little cumbersome, esp mid game. you have to remove the mag, rack the bolt, whip out your allen key, then adjust; i just cut a hole in my stock and stuck the allen key in it. there's also tdc mods out there
a little pricey, but pretty worth it
YOU DON'T HAVE ONE!

"Tight fit in my WELL VSR-10, but I think there was a dent in the barrel I was using. Hops very well. If you're wondering where to start with upgrading, this is a good first insert.

"This really Improves air seal, shot groupings and FPS.
In order to get the maximum performance the following

A Maple Leaf Autobot, Decepticons, MR Hop, Diamond, Delta, Wonder or Super hop up bucking or something similar [preferably 50 to 70 degree hardness]

Maple Leaf or Panthera hop up nub

Any decent inner barrel

and of course decent trigger/cylinder combo and you are all set!!!