Dis-appointed - LANTAC Dragon Muzzle Brake

I own 3 Dragon for my 308's and they are great. But for my MPX, it sucks, 1st, I didn't care that it was louder than Magnums but did not make a difference on recoil, the flash hider was less than the dragon, it looked really cool, but when it came to shooting, the shots were way off, I tried different ammo and grains and about every other 3 shots, I hit high and right or just right at close range (30 ft) and at 75 feet the shot were way of course, I re-timed it several times and No Joy. I thought for awhile the pistol was bad or the ammo was bad, but as soon as I put the original flash hider back on, I was hitting bulleye's and overlapping consistently over 200 rounds, So I DO NOT Recommend it for the Sig 9mm,but great for the 308/762. I think i will contact LANTAC and maybe got a dud, but for now, no way...