Howdy guys,

I am looking for an effective muzzle brake for a Colt 9MM 10.5" SMG upper. The Colt barrel is 1/2x36 thread pattern but a 1/2x28 thread pattern brake will work with an adapter. Experienced shooters don't have too much trouble with the high cyclic rate trying to move the gun up and to the right. But an effective brake would be of value to the newer shooters. Anybody have a brake installed on their M16/9mm upper that works well? TIA!

non of them work that great on 9mm, not enough gas and its all burnt up by the time bullet exits.

I am waiting for Gemtech to make another run of their 3 lug MK-9K cans. But it may be quite a while from what I am hearing. May adapt an AK74 type muzzle brake and see if it makes any difference.

Other than a can, which would certainly be the best, a heavy muzzle brake would work as a “muzzle weight”. Something along the lines of a Noveske “Pig” would work well, using the thread adapter you mentioned.

It won't do much

not enough gas to make it work.

I would stick a pig on the end, as mentioned above

Something worth mentioning about the Colt 9mm AR platform: I have a couple of Colt 9mm carbines/uppers. Since they are recoil operated, they do not utilize a gas tube. So the barrel nut is not locked in place by the gas tube as on a gas operated 5.56mm upper. The barrel nut backed off on one 10.5” 9mm SMG upper which can lead to a dangerous excessive headspace condition. These Colt 9mms are used as needed for SD/HD/hunting, so I sealed the barrel nut to the receiver with Rocksett. If the Rocksett method fails, I will drill the front of the receiver to accept a shortened gas tube in order to lock the barrel nut  in place. Or I could just swap out the Colt 9mm upper for a standard 5.56mm upper with the normal provision for a gas tube. .02

maybe a Bowers AIMs brake?

I do want to get some for my 9mm Subguns, but there are so many choices.

I bored an AK74 muzzle brake to 0.400" ID for 9MM use and installed it on a 10.5" 9MM upper. Just need to go fire it to see if the modified brake has any real effect on muzzle rise. Might have a chance to make the Texas/U.S. Law Shield shoot over at Top Gun Range in Houston tomorrow night.

EDIT: Sorry guys, I retire in July & needed to attend a retirement seminar tonight so was unable to test fire the AK74 muzzle brake. Will report back after I do.