As an update to this, I finally sent my MPX back to Sig describing my suppressor zero shift issue. They said the zero shift they discovered (4 inches at 25 yards) was “acceptable,” and “combat effective.” I reiterated that by 50 yards, the shift was more like 12 inches, and that moreover the group opened up significantly at that point as well. They opined, in essence, that 50 yards was beyond what they considered a “realistic” engagement distance for a 4.5-inch barreled 9mm weapon.
So there you have it. Don’t buy an MPX if being able to reliably hit a B8 at 50 yards with a suppressor mounted is particularly important to you.
It’s not super important to me, since this was to be my discreet backpack travel gun, and I probably wouldn’t bother packing a suppressor with it anyway. But I am still a bit disappointed.
Sent from my iPhone using Tapatalk Pro
I would be really effing pissed, not mildly disappointed.
I have a pair of suppressor alignment rods from Geissele just for this purpose. I got burned exactly this way on an AR barrel, and bought the 5.56 and 7.62 rods as insurance. I need to get a 9mm rod as well, I have a lot of 9mm quiet stuff.
Geissele puts the rods on sale periodically, and Brownell's does so as well. They are a worthwhile investment.
“There is no growth in the comfort zone.”--Jocko Willink
"You can never have too many knives." --Joe Ambercrombie
Sig also more or less blamed the mount and suppressor, muttering something about “tolerance stacking.” They direct threaded one of their suppressors onto my MPX to test it, but even then it still shifted 4 inches to the left at 25 yards.
I’ve used my suppressor on 4 other pistols/pistol caliber carbines, with less than 3 inches of shift at 50 yards, so I don’t think it’s the suppressor. I also tried, on my MPX, 2 different tri-lug mounts, with the same disappointing results. Maybe both mounts are goofy. But I don’t feel like buying a third mount to find out.
Sent from my iPhone using Tapatalk Pro
I bet the threads and/or barrel face are not perfectly orthogonal to your bore. You don't have visible evidence of baffle strikes--yet. But I bet your bullets are skimming the baffles. If this was my gun, I wouldn't risk damaging the can--or worse, a catastrophic and dangerous issue. I've only seen a major baffle strike once, but it was bad, and I was right next to it when it happened. Do not want to repeat.
Last edited by Clusterfrack; 12-15-2020 at 02:34 PM.
“There is no growth in the comfort zone.”--Jocko Willink
"You can never have too many knives." --Joe Ambercrombie
I agree. My MPX is going to be a no-suppressor gun from now on, which is fine for my primary use of it. It’s just sad that such an expensive and otherwise awesome little gun has such a defect, and moreover that the company which made it thinks that such an imperfection is acceptable.
Sent from my iPhone using Tapatalk Pro