AR9 build: Colt/Uzi or Glock mag

[awp_101]

OK, at this point the only advantage a Glock mag lower gets me is a steady supply of cheap-ish mags and but it's duplicated by the Ruger. @RevolverRob I've never messed with the Hahn, does the bolt catch have to come out for installation? Not a big deal if it does, I've just never seen it mentioned that I recall. I think I need to hit Brownells and see what they've got...

As an 80's kid the mags look cooler too!

Attachment 51193

As a child of the 80's myself, I approve of these images. I always thought the suppressed Uzi from Cloak and Dagger was hot hot hot too:

[Dennis]

...

I've never messed with the Hahn, does the bolt catch have to come out for installation? Not a big deal if it does, I've just never seen it mentioned that I recall. I think I need to hit Brownells and see what they've got...

I would rather have a suppressed .380 that makes bad guys tumble end over end!

There are bottom and top Hahn adapters. The top install is more "secure" but you need to remove the bolt catch to install and no LRBHO. The bottom can just be pushed in from the bottom and is secured with a nut/bearing but you get LRBHO.

Choices...

Dennis.



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[RevolverRob]

OK, at this point the only advantage a Glock mag lower gets me is a steady supply of cheap-ish mags and but it's duplicated by the Ruger. @RevolverRob I've never messed with the Hahn, does the bolt catch have to come out for installation? Not a big deal if it does, I've just never seen it mentioned that I recall. I think I need to hit Brownells and see what they've got...





As a child of the 80's myself, I approve of these images. I always thought the suppressed Uzi from Cloak and Dagger was hot hot hot too:

Hahn makes three different blocks - bottom load, top load, and dedicated. The top and bottom load blocks are like the Promag or old Spike’s blocks. They use set screws (bottom) and friction (top) to secure the magazine block in place.

The bottom insert type usually locks the bolt back without any further changes, but may be more mag finicky. You also may have to adjust the tension regularly or the block and mag will wiggle. It’s ideal if your lower isn’t dedicated. You insert the block into the mag well, tighten the tension screws and in theory you’re ready to go. In practice they usually take more fine tuning. The top-load block basically just fits into the magwell from the top of the receiver and uses a 9mm-specific bolt catch, if you want bolt hold open. If you don’t care about bolt hold open, then you won’t need the catch. The “top load” is basically as close to the original Colt SMG pattern as you get outside of Colt parts. Remember the Colt SMG is an open-bolt gun, so I think Colt didn’t bother with a bolt hold open in the initial design. The standard manual of arms with open bolt guns is, “If the bolt is forward the gun is safe and/or empty.”

That said the dedicated block is the better choice, in my opinion, because you don’t need a 9mm bolt catch. But yes, you do have to remove the standard bolt catch, fit the block, then reinstall the bolt catch. Basically it’s for if you have a “dedicated” lower to being 9mm converted. I kinda view the bottom and top load blocks as vestiges of a by-gone era. These days with so many cheap and plentiful lowers, it seems unlikely you do not want to just dedicate one to the caliber.

[RevolverRob]

I would rather have a suppressed .380 that makes bad guys tumble end over end!

There are bottom and top Hahn adapters. The top install is more "secure" but you need to remove the bolt catch to install and no LRBHO. The bottom can just be pushed in from the bottom and is secured with a nut/bearing but you get LRBHO.

Choices...

Dennis.



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That’s why the “dedicated” is the best. More secure, last round bolt hold open, no specific parts needed (the top can give your LRBHO, but only with the “9mm” bolt catch).

[Dennis]

That’s why the “dedicated” is the best. More secure, last round bolt hold open, no specific parts needed (the top can give your LRBHO, but only with the “9mm” bolt catch).

Unfortunately my ability to buy new lowers are limited given my location. Luckily I have a Colt Sporter 9mm already but just a couple "pistol" lowers... Although if I lived somewhere free I may have like 100 lowers!

Dennis.



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[CleverNickname]

In my experience, a dedicated mag block is a pain to install and remove. So if you can't easily change from 9mm to 5.56mm (or whatever), why not just get a dedicated 9mm lower instead?

e: n/m answered my question while I was posting.

[Dennis]

In my experience, a dedicated mag block is a pain to install and remove. So if you can't easily change from 9mm to 5.56mm (or whatever), why not just get a dedicated 9mm lower instead?

e: n/m answered my question while I was posting.

If you can buy whatever you want then definitely dedicated. More toys better!

Dennis.


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[RevolverRob]

In my experience, a dedicated mag block is a pain to install and remove. So if you can't easily change from 9mm to 5.56mm (or whatever), why not just get a dedicated 9mm lower instead?

e: n/m answered my question while I was posting.

These days this is probably the most right answer if you want colt-pattern: https://www.primaryarms.com/cmmg-ar9...lower-receiver

Correction: I got it wrong - the original Colt design was a closed bolt gun. Why the hell did Colt redesign the bolt catch?

I would probably opt for the top-load block if I only had one lower. You’re still going to have to remove the 9mm upper to fit a 5.56. You don’t get last round bolt hold open this way, but it’s probably a better trade than the tension setups of the bottom-load blocks. I like Hahn Precision parts, but I’ve never seen a bottom-load block not need to be tuned and retuned when removed and reinstalled.

[TGS]

The popularity of AR9s tickles me a little. When we had finally ditched our Colt SMGs completely as an agency a few years ago, I'm pretty sure it was just us and NY DOC ESU using them.

They were universally loathed. They broke down constantly. We loaned a bunch to another federal agency's protective team after an active shooter incident revealed they had a substantial lack of long guns (their primary being the MP5), and they opened the crates, checked'em out for 5 minutes and put them back in the crates as a last ditch resort and decided to simply go short handed until more MP5s were transferred in.

It's not a weapons system I think I'll ever get the itch to buy, even for nostalgia reasons.

Correction: I got it wrong - the original Colt design was a closed bolt gun. Why the hell did Colt redesign the bolt catch?

I'm not sure I follow, but were you saying that Colt SMGs don't have bolt hold opens or was I reading something incorrectly? Our Colt SMGs most certainly had bolt hold opens.

[awp_101]

For my wants/needs/purposes a drop in will fit the bill just fine. Brownells has top loads from Hahn as well as their own branded version with a 32 round mag. If I add the same mag to the Hahn it's less than $2 difference.

Why the hell did Colt (fill in the blank)

That could be the first sentence in every chapter of a book on Colt history.