What kind of variance are you seeing?

First off, ditch the can and see what happens. The POI can change dramatically with a supressor but usually not that much at that distance. My guess is a loose optic mount. Remove the can as a variable first and see what happens. If thats not it, then try using an O ring with the supressor to help keep it tight. I assume you are using a direct thread mount?

 

I am. The southpaw screw-on keeps stumping me

Would the O ring sit between the piston and the barrel?

 

Yes snug the o ring up to the back of the threads on the barrel and then tighten down the supressor. First things first though, how does it shoot without the can? Also, make sure you are using the same ammo while figuring this out as that will change POI as well

 

I'm going to try without the can next range day, thanks. Consistently been shouting 147gr

 

I can only tell you that the first time I shot my MPX with my Romeo 5, the Romeo 5 failed and SIG sent me a new one. In the mean time, I put a Romeo 3 on my MPX and it has been spot on since.

 

thanks for the feedback- when you say it failed meaning you lost the red dot?

 

Bad optic most likly. Best to have a set of flip down irons installed in case your optic fails.

 

This

 

I've mentioned before that 3 of the members of my weekly shooting group have MPXs with Romeo 5s.

All of them loosened up on their mounts and did it multiple times.

The fix was Loctite Blue. We all used that and the problem went away.

 

Great info, thanks. It doesn't feel loose on the picatinny but I guess it could be. Where did they apply the loctite? I've used it on threads before but not a mount

 

the red dot moved to where it could no longer be aligned. did it after about 3 mags worth.