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Posted: 11/12/2005 8:18:23 AM EDT
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I've been looking at setting up a 9mm AR upper for training purposes - primarily to shoot steel. I've had the Hahn adapter recommended but there are three different models - the dedicated, the top loader, and the bottom loader. Can anyone explain the differences and what modifications are needed to an Uzi magazine to make them work. One thing I don't understand is how the magazine is released - is the factory release used or is it a flapper system? thanks in advance...... |
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Check this FAQ. It should help you a bit. www.ar15.com/forums/topic.html?b=3&f=15&t=108261 |
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The standard top load block must be used with a 9mm style bolt catch if you want functional last round bolt hold open. The bottom load block has an actuator and is used with the standard bolt catch. The dedicated top load block is the same as the bottom load and has an actuator for use with the standard bolt catch, however you must remove the bolt catch, install the block from the top and then re-install the bolt catch - hence the "dedicated" notation. All use the standard mag release and the mods required to Uzi mags are cutting the mag catch notch and opening up the slot at the back of the mag. There's some threads abotu how to modify them and there are dimension listed on the Hahn website for the notch. |
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I just got my Hahn dedicated mag block and my initial impressions are that I'm going to have reliability issues. The feed ramp that is built into the mag block has the ammo hitting the chamber of the barrel a bit low. I chambered about 50 rounds manually and the cartridges are smacking into the barrel just below the chamber. About 10 out of the 50 did not feed correctly. I am using a RRA 9mm upper. I'm going to shoot it tomorrow and I will let you guys know how the reliability goes, but so far I'm not impressed. I plan to shoot 115 gr round nose, 124 grain FP's and 115 grain hollow points to give me a good overall picture of reliability. |
What mags are you using? |
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Today I used my Hahn precision dedicated mag adapter and I must say that I am impressed. This thing would not malfunction no matter how hard I tried. I used round nose, flat point, and hollow point cartridges and easily put over 400 rounds through it today and did not give me one problem. The bolt hold open feature worked every time when I was using the Colt mags. My scepticism was unwarranted an I would without a doubt recommend one of these mag blocks to anyone who is building a 9mm AR. I still can't get over how well it performed with zero tweaks. |
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Best reliablity is with Colt mags...even so you may have to replace springs with Wolff springs when they get weak. I have Colts that are years old, dropped in the dirt, kicked around, and abused.....they still run great. Just refinish when they get ugly. Promags are shit....hit and miss with being reliable....inevitably they fail. For serious use only the Colt mags will due. Converted Uzi mags work ok. Never use Promags for serious use if you value your ass. |
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No you can not leave the 9mm bolt catch in while using the top load blocks, that is what the bottom load blocks are for. Top load blocks are for people who do not care about last round hold open or people who install the 9mm bolt catch which also gets in the way of removing the top load blocks. Pinned in blocks are for those who never care about .223 Bottom load blocks are for those who swap 9-223 routinely and want bolt hold open |
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You cannot use the 9mm bolt catch for .223 for any adapter or situation. The Hahn Top Adapter CAN be used with a 9mm bolt hold open catch......you drop in the adapter......install the 9mm catch over it......you DO lose the ability to pull the adapter out instantly. I have only one rifle I switch between calibers with.....the rest are dedicated 9mms......one of them is the Top Adapter with 9mm catch. |
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