Will work on a dedicated 9mm upper.
I bought this knowing it was designed for use with a standard AR upper, but I had an idea that I could adapt it to my dedicated 9mm upper that has a much smaller ejection port. I took just the nylon deflector and glued it to the side of my FM upper just behind the ejection port. Works great, I am left handed and use a suppressor and this has completely eliminated any gas or particulates from hitting my cheek.
Would you recommend this?
Yes, I would recommend to a friend
Works Fine. Not sure that it's needed?
There really isn't much to this. The dust cover is shortened (obviously) to allow room for the little defector nub that sticks out. The dust cover pin just slides through the deflecter nun. I like to install the dust port cover before I install the barrel. The issue that I encountered is you can't use the typical clam shell type upper receiver block that most guys own. The clam type vise block Doesn't accommodate for the deflecter protrusion. I suspect that guys try to install this part from the wrong direction because they don't have the correct vise block. I used the DPMS Claw type upper receiver block. That allows the barrel to be installed without encasing the upper. As far as grinding on parts or shortening parts; I have no idea what these guys are talking about. Just remove the barrel, and install the dust cover before installing the barrel. That's the correct sequence. Good luck.
Customized Fit
I like this design better than the old Colt design. It looks more modern on newer AR rifles and is lower profile. The problem is depending on your upper receiver you may have to custom fit the deflector to line up with the ejection port and the ejection port cover rod for it to work properly. A Dremel tool will come in handy for this purpose. I have CMT's and Guntec receivers that the rod would not line up until I took some material off the deflector, but after that, they fit tight against the receiver without any blow by. Just make sure you don't make them too tight, as the door can scratch the deflector when opening and closing.
Works as intended
Ordered this after shooting my AR9 with a supressor the first time. As a left handed shooter, I was getting peppered with unburned powder. This product massively cut down on the amount of blow back gas and debris. Good product at a fair price. Only con is I had to do some fitting on the deflector. The hole the pivot pin passes through was not parallel to the axis of the hole on my upper receiver. Some sandpaper and patience took care of that issue.
9mm Build
I used this kit for a 9mm build, it fit good and is great for the build, I would buy again.
Not enough info.
Not sure how the gas deflector is supposed to fit. Initially it kinda flopped around. There is NO apparent way to secure the top of it to the upper. That somewhat defeats the purpose of having it. It's only for a dedicated 22 though, and the upper is just polymer, so super glue to the rescue. This would definitely NOT work for a larger pistol caliber. Good thing it wasn't expensive.
Not Good at all.
CMMG changed the design! And it's not good; not good at all! This is my second review on this product, because it's not the same product! My first review was on the original design. This isn't even the same product. The original was okay, but I'm not sure it's needed. I had no idea that it was a different design, and I was cussing Brownells when I first examined this item. Then I checked the web site, and Brownells has the correct, accurate photo of the item. I just didn't notice that CMMG changed it. Brownells should re-list this item and not use reviews from the original design. To do so misrepresents the product, and again damages Brownells' credibility. Bait and switch! This new hot garbage is complete trash. You guys are going the wrong way.
CMMG Ejection Port Cover w/ Gas Deflect.
Loose/poor fitting, open spaces allowing gas to leak. Attempted to mount on a standard Anderson stripped upper receiver. Older design was much better!
