Reviews & Ratings for Pro Mag AR-15 / M16 9MM Magazine Adapter Block For Colt 9mm SMG Magazines, Quick Change — 67 reviews — Page 1

This unit worked fine for the first couple of mags. On the 3rd or 4th mag, the cheap pot metal bolt hold open actuator snapped off when inserting a new mag. I do not recommend this product. Spend the extra 15 bucks for a good one.

I chose this bc I don’t like the angle of Glock mags on AR9’s. No last round hold open.

I shot one mag with 115 gr and the last round bolt open catch broke and not it won hold open

Its still run fine no other malfunction just wont open on last round

If you are building a PCC and starting from scratch, I would recommend using a dedicated AR9 lower. But if you have a AR15 lower and looking to build a 9mm PCC this will work but you get what you pay for. The LRBHO tab broke after 1st spent magazine. I ran about 140 rounds thru with no failure to feed or other catastrophic issues, using round nose FMJ. Colt metal metalform mag catches and releases with no issues. Works good for the price

The adapter fits well, fed well, but when I went to insert a second magazine the bolt catch broke..other then that it functions decent

During installation the adapter buckled because it was too large. It was impossible to remove without destroying the adapter to save my lower which was a Colt M4. I can not recommend this produce.

God awful product, was broken before it got to me, just spend the money on a kak block. When installed it was loose and janky is the word that comes to mind. These are hit and miss. Some are great most are garbage. I wouldn't waste the time or effort again.

This product worked as described. I chose this over the brands because I live in a state where we cannot have detachable magazines. Since this adapter uses the same mag release as my AR, I remain in compliance. My only gripe is the difficulty to remove it to switch calibers.

The other negative reviews say it all. I guess I should have listened myself. Cheap materials used in crafting this product. Instead of steel they used a pot metal piece. I hope that .05 I savings was worth all the negative reviews. And for what it's worth - OP stop pedaling this junk !!

The one I received came with no instructions. Maybe a return? Anyway, I looked up the Youtube video on how they say to install it. I now see why they call this a "two piece" design, because they recommend punning the front feed ramp portion off, jamming the back piece in, pushing it rearward, and then sliding the feed ramp portion back on. I tried doing this on my Essential Arms receiver and it's really tight. Like it feels like it'll break tight when you go jamming the rear half in the magwell. It just doesn't fit because of the hump on the side and the tabs on the top. I'm sure I could probably get it in that way, but it would distort the heck out of the rear portion doing it. I recommend using this thing as a top loader and do the replacing the roll pin with an "R" clip thing if you're going to be switching it back and forth. It's WAY faster. So I guess you could say this thing is "sort of" a two piece, but not the kind of two piece that gets pinned in place or held in with screws. I seriously wonder if everyone who had one break caused it by jamming it in from the bottom? Be aware AR magwells are (used to be?) all over the place as far as fit goes. It might work fine in a loose one. I have an Olympic receiver that the adapter won't even fit in from the top, but it's not surprising since a lot of mags fit super tight in it, and sometimes need to be sanded on to get them to fit.