Tuning M3 Weep Hole Leak

Nope, spoke too soon, still leaking through the atmosphere weep hole. I've replaced the o-rings on the piston, plunger and inside the housing. Not as frustrating as not being able to find a leak, but can't understand how this is still a problem.

Couldn't replace the one between the brass cup and chassis. It appears to be 7x1.5. Can anyone confirm? I can't find a schematic/BOM for the internals of the 1st reg. Thanks.
 
Circling back with a hopefully update. I have my 2nd reg at 90 bar, and getting ES of 2-3. Was trying to set the 1st reg at the recommended 30-40 bar higher and ended up at 130 bar. After multiple 1st reg inspections, o-ring replacements and lubrication I still couldn't stop the leaking. So I tried turning up the reg pressure. Sure enough leak stopped and no gauge movement overnight. So, it appears it was set too low to hold. This is with a washer setup that looks like this (())(())(()), so maybe others can tolerate different pressures. Also as most know the FX gauge is useless, I need to replace it. So I set things using the 2nd reg gauge with an open 2nd reg, like is done with the Maverick. Once again, appreciate the support here.
 
Good to hear you got the leak sorted. Personally I wouldn't set first reg below 150 bars, like @jerrymail mentioned the reg is setup for 150 bars or higher. Then it's just my personal tuning preference I alway use highest reg(second) pressure I can get away with, this in my personal experience is a lot easier to tune and more efficient. If you shoot slugs, high reg tunes generally have less muzzle blast which makes a very noticeable difference in slug accuracy. 



Also my personal preference I won't shoot the bottle pressure below the first reg setting to maintain consistency of first reg. 
 
Naw, spoke too soon. I can't solve this one. All o-rings replaced several times, tried a couple different washer configs, multiple pressure settings, but still get varying levels of leaking through the weep hole. I'm assuming it has to be related to either the small o-ring on the adjustment screw, but this is less likely I think. Primary suspect is the o-ring on the piston. FX asked me to send if back again, but this would be the third time to them after a prior repair by the dealer. They did send me a replacement piston assembly (included o-ring), but no difference. Assuming this is the trouble spot, any thoughts on the brass bushing? Other thoughts are of course welcome. I've also replaced the 4x1.5 o-ring in the body of the regulator. I used NBR 70, assuming that was correct. I'm not sure how much pressure that even sees, it may just aid alignment of the piston. FX said they don't have any bottle adapter assemblies to swap with me at this time, but maybe I should wait for that. Appreciate your ideas. Thanks.