[MadMax]

I took a long hard look at WA hop up design and surmise that the reason they they suck is because the bb is preloaded into an oring shaped rubber retainer well ahead of the hop up nubbin.

In shooting, I think the bb inconsistently releases from the retainer and bounces off the hop up nubbin in different ways.

I can confirm that a bb set against the hop up nubbin before firing results in much more consistent performance.

As a test, I modified the nozzle body by press fitting a metal extension about 6mm long. The extension pushes the bb past the retainer area and just against the hop nubbin. A lengthened reed valve is necessary for proper functioning of the pneumatics.

Unfortunately the GBB is unable to load automatically with this modification. The lengthened nozzle interferes with bb extraction and loading from the mag. However, by dropping a bb in one at a time through the opening in the slide, one can take single shots which are very consistent. In this configuration, single shots fly about as consistently as my P90 or MK23 NBB. Very good range, but not combat effective because of the loading issues.

The purpose of this test was to determine if the retainer scheme used by WA is the source of their poor consistency.

I've contemplated a custom hop up body design. Modify the barrel configuration to move the hop up back by 6ish mm and remove the rubber retainer. Shift the whole thing back so a standard nozzle sets a bb against the hop up before firing. Unfortunately this requires a custom cast metal assembly and a completely different hop up adjustment.

I think one could sleeve a metal ring around the barrel and hop up similar to the SCW arrangement. Instead of using the current horizontal adjustment setup, tap a screw into the ring (bigger ring than the current design) which points upwards and butts against the barrel. Tightening the screw would pull the ring downwards and apply more force to the hop up.

This arrangement would require removal of the slide to access the adjustment screw through a thru hole in the bottom of the barrel ass'y, but at least the performance would be actually good. Besides, pick an ammo and make your adjustments once and it'll finally shoot well.

As to LRB, they're not that easy to find. I'd love to try one, but if they use the bb retention scheme that the stock arrangement uses, I'm sceptical.