Modify VSR 10 Hop Up Bucking

Product Information:
Purchased this for a KJW M700 build. I usually advise Nineball buckings, but as they are getting harder to find and more expensive, I figured I would give this one a try, as there was little information out there on it. I wanted to share my experience so that others can hopefully make a better informed decision.

Upon first inspected, I noted that the nub inside is a typical flat type. I was glad to see this, as the Firefly style 2-prong nubs were typically too prone to tearing for my liking. However: the rubber Modify chose to use is very soft. So soft, that I was hesitant to even install it in the M700, which was going to be shooting 550 FPS once the HPA rig was adjusted. But I decided to at least give it a try. I slipped it over the inner barrel, put the 2 halves of the hop-up over it, tightened down the screw, and found that the bucking was so severely undersized that I could slip the clam shell hop-up right off the bucking without loosening the screw that held the 2 halves together. The hop-up would slide back and forth over the bucking with ease upon re-installation. I would estimate a .030"-.040" undersizing of the outer diameter.

A soft bucking is not a bad thing for lower FPS builds, but the poor sizing would create massive blowby inside the hop-up assembly. I highly advise against this bucking.

Pros:
Standard flat nub (debatable, but favorable to me)
Cheaper than Nineball

Cons:
Severely undersized
Very soft (softer than Nineball, King Arms, factory KJW, factory JG BAR-10...)