GBL Airsoft "The Captain" Metal Hop-up Unit for GHK M4 Series Airsoft Gas Blowback Rifle

"Captain America hop up is the best hop up I ever seen in my life im a fan boy of GHK and GBL I recommend this upgrade to everyone!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

"I actually bought this to install onto a G&P WOC Challenge kit. Since it was made for the GHK system, there are two timing tabs and one must sanded off before it�ll fit the G&P barrel extension (or, conversely, an extra notch must be machined). Build quality is good, but the hopup arm has slightly loose tolerances and could use a bit of shimming. A large o-ring snugs the unit into the barrel extension as well as steadies the hopup arm.

The biggest benefit of getting the GBL is that it allows the use of VSR type buckings and barrels. The unit includes what appears to be a Maple Leaf (ML) Delta bucking. I installed it with an ML Diamond instead (with the split nub), along with an ML Crazy Jet barrel.

The GBL solves the accuracy problems I was having with the G&P kit. Previously I had swapped the stock hopup/barrel with a stock GHK unit/AEG barrel with only marginal improvements. So, in short, I�d highly recommend the GBL unit. If it could improve a G&P it�ll surely improve any GHK M4.

Disclosure: All testing was done with a GHK G5 magazine, modified to fit the G&P mag well.

"I bought this because I needed a new hop up... GHK STANAG mag feed lip broke, I double fed, and burst my plastic hop up... but MAN IS THIS AMAZING. I'm actually glad I had a reason to upgrade! The metal is extremely well built. When I'm double feeding, it just breaks the BB and I walk off to clean it off real quick. The bucking didn't want to co-operate to well upon insertion to the unit itself. Use a lot of lube and just don't give up. VERY SOLID PRODUCT, all the GHK players on my field use this product, or the TNT hop up system, the two option are simply the best for your GHK M4. Don't forget to pick up an AR wrench or you will never be able to change this yourself, otherwise get a tech to change it.

"This was ok. My gun works but sadly double feeds more than ever with this hop up. It didn’t really increase my range it actually kinda decreased it. Maybe I installed it wrong but it didn’t come with directions and I couldn’t find specific videos for it. Looks great and is somewhat solid. Part of the lip on the hop up got bent just from me testing it. Again I’m not a great tech but I had put an upgraded inner barrel in the gun before and knew how to disassemble and reassemble it. I’m sad with its performance. I would recommend it only if you really know what your doing I don’t know about the tnt one if it’s any better but it was a pain to get it set up and to not have it work properly was just a disappointment. maybe it will take some time just tinkering with it but over all not impressed.

"just aarived, was installing on my ghk m4 o-ring shredded when istalling
om upper receiver.

"i was looking forward to installing this in my gbbr but the bucking that this unit came with was nowhere near the right size. it ended up ripping itself apart and the large o ring got shredded when i went to go put it in my rifle.