Angel Custom Enhanced Recoil and Hammer Spring Set for Marui M9 Airsoft GBB Pistols
(Type: 170%)

"Installed these into my WE M9 and it adds some serious kick to it, includes a nice snap when I let the slide go.

"Excellent parts, just the perfect one for my HFC semi/full auto M9, the installation of the long slide spring is pretty much simple and you can feel the difference immediately!
The hard part comes when you have to install the other spring that goes inside of the grip of the gun, it is a little bit difficult to install but that depends on your skills (I'm pretty much a noob on this lol)

Overall a nice upgrade but you need to keep in mind that it may wear the pistol faster, if you are ok with it, then is a nice thing to add to that shooting experience.

"i put this in my hfc m9 and the recoil was insane, aswell as the fire rate picked up to about 1500 rpm until i shot 400 rounds out of it and the full auto sear broke. still has snappy semi auto though! i would reccomend a 150% spring over the 170% because occasionally it will fire a burst because it has too much back pressure and cannot fully reset the semi-auto sear stop.