I'm going to be the one to buck the trend here. I think the polymer of the kit is fine, the muzzle shroud is wrong, as it wasn't designed for a firearm. The stock just holds the gun, nothing more, and is very solid. All the parts are dimensionally identical, and probably from the same mold.
The only area critical is the area just in front of the pistols muzzle. By being shorter, the muzzle shroud allows the expanding gasses to interact directly with the polymer stock, and could not possibly be expected to last. The whole concept is based on that metal sleave being there. I'm amazed it lasted 100 rounds, frankly.
I'll bet if you take the airsoft muzzle shroud, and put it on a real Roni, you get the same results, and, I'll shoot either one with the proper muzzle shroud, albeit, wearing eye protection.
Quote :Stick that in yer pipe and smoke it.:
I must be smoking the same stuff ...
As that is what I plan on doing with my kit as I bought the correct shroud from Questar for my 34 .
IMHO the barrel fits inside my shroud far enough that the gases will go out the front as designed and not to the side as in the OP,s experiance.The gap near the muzzle is less on mine...Look at the 2nd pic .When my kit is installed the end of my muzzle is actually in the hole a bit so the side pressure the OP experianced isnt there.
Glock 34 Shroud from Questar
https://shopquestar.com/shopping65/shopexd.asp?id=1399&bc=no