Well, I messed up, and it’s because I failed to correctly read the German parts diagram. The 4.0x1.5mm o-rings are too large- they’re for the .25 caliber model. I needed 3.5x1.2mm for my .22 caliber. Captain O-Ring was out of stock on the 3.5s, but I found them at Oringsandmore.com. 25 for...