Designed for quick caliber change between 5.56mm and 9mm with minimal effort. Adapter loads in from the bottom of the magazine well and secures with a tension device. Ideal for users using Colt type magazines and frequently changing between calibers that desire the bolt hold open feature. Holds the bolt open on the last round with Colt type magazines. 9mm Colt pattern system. Construction 6061-T6 Billet Aluminum body MIL-A-8625 "F" Type III Class 2 hard black anodize tool steel bolt hold open actuator standard 9mm Colt type ejector parkerized steel components Features Colt pattern system that uses standard Colt type and modified Uzi magazines. bolt hold open on last round with Colt type magazines tapered and funnelled magazine well for smooth insertion and minimal rotational movement built in bolt catch actuator is designed to allow for fouling and fine debris tool steel feed ramp is designed with scalloped surfaces to provide superior functioning even with hollowpoints
15 Reviews Hide Reviews Show Reviews
This item appears very well built!! It is slightly difficult to get locked in initially but becomes easier after a bit. I'm running this on a registered receiver (full auto 9mm).
Once inserted, it performs flawlessly. BUT.... after a mag dump the magazine release is impossible to depress. During operation, the Hahn Mag Block must be moving (up or down) against the magazine release causing tension to the point the mag. release button cannot be depressed.
You have to push the magazine back up into the weapon, then you can depress the mag. release button easily.
If this is the only issue, I'm sure it will work itself out after a dutiful break-in period.
installed 9mm mag catch, mags lock in tight now, LRBHO works with metalform mags, function tested feed and eject fine. have not had a chance to fire it yet, but looks good so far. just get a 9mm mag catch, 9 or so $ and works great
very well made, but had to do some tweaking(file one edge) to get it to slide into my Anderson lower, fits very snug. remember to back out the set screw all the way to slide it in. mags will not lock in tight, fall out (metalform) do not think it is mags or magwell block. mag catch does not protrude far enough, ordered another for 9mm. will advise when i get it installed. remember this takes up some space in the side of mag well.
This is the best mag adapter on the market today, easy to install, work perfectly in ploymer lowers. !!!
Fits very snug, very well made and is not a piece of junk
After a long week of research for the right 9mm block I ended up with the bottom load Hahn block.
Fit and finish is way better than I thought it would be. I slid it right into my SBR Colt SP1 lower and it fit like it was made for it. Functional with Colt pattern magazines perfectly. BHO worked as well.
I later that night tried it in my Colt M4 marked carbine and the block will only go in about 1/4 of an inch and it stops dead in its tracks.
I can see by the rub marks on the block it is sticking at the rear (back) of the magwell.
All mags GI and all Pmags drop free from this Colt. I have more investigating to do on this situation. I'm not really too worried about it as it fits into the SP1 which I bought the block for anyway.
This takes just a few seconds to install or remove if you're switching between 9mm and 5.56/.223. It took me longer to write this, and it'll take you longer to read than it will to actually install.
No instructions provided but it's dead easy:
- use the provided hex wrench to loosen the hex nut that holds the retaining cam
- push the magazine release button
- insert magwell block
- release magazine release button
- insert 9mm magazine and make sure that it locks in and drops freely when release button is pushed. If not, you probably need to push the magwell block in a tiny bit more
- use the provided hex wrench to tighten the hex nut that holds the retaining cam
500 rounds through and no failures to feed.
This mag block is very easy to install and fits like a glove. I own one from another manufacturer that no longer makes these inserts and this one is easier to install (only one set screw) and glides perfectly into the magwell with no wiggle room. The ejector is also easy to adjust to help prevent jams.
Block is in a registered lower with Hahn buffer and Modular bolt. Fit and finish are top notch. Can be back in 5.56 in a minute. 200 rounds and it has not budged even slapping mags into the gun with the bolt held open. Some of the ASC 32 rd mags need a 9mm mag catch to stay in the gun. Here is the run down on what mags worked from me, and if I had to do anything.
Metalform - 100% 32 round dump 1st time. No mods or break in. BHO works everytime.
Converted Uzi - 100% 32 round dump 1st time. Only had to cut the catch slot on the mill (Use a carbide end mill unless you want to trash you HSS steel ones). Have not done the hold open mod yet as I need to order some spring steel the correct thickness.
ASC 32 rd - Would not feed last two rounds without moding the front top of the follower as it was hanging on the feed ramp. Needed a 9mm mag catch to stay in the gun. Once mod was done, hold open worked every time and ran 25ish rounds in one burst. They seem to need 3-4 full cycles before they start working 100%. Next time I will try to wax the inside of the mag before using a new one. Plastic follower design has potential to have issues that may occur/reoccur with wear.
ASC 20 rd - Would not feed last two rounds without moding the front top of the follower as it was hanging on the feed ramp. Once hold open mod done, hold open worked every time. 20rd burst no issues. They seem to need 3-4 cycles before they start working 100%. Plastic follower design has potential to have issues that may occur/reoccur with wear.
Promag plastic - ha ha ha, the rounds would not even stay in the mag when inserting it. Someone gave me one so I had to try it. If you carefully inserted it, the rounds would hit above the chamber and jam every time no matter how many rounds were loaded. Inserted hard making careful insertion troubling, and would not drop free.