9mm AR upper

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cyclone72
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9mm AR upper

Post by cyclone72 » Sat Oct 10, 2015 4:18 pm

Who makes a good 7"/9" upper in 9mm?

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Frank Castle
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Re: 9mm AR upper

Post by Frank Castle » Tue Oct 27, 2015 8:19 pm

I decided to make my own after looking at the options. Its a fairly easy build as it has no gas tube so go as short as you want. I went with an ADCO 5" barrel as they offer them with a 1/2x28 thread unlike others. I then went with a 3 lug and added Rocksett to keep it there. Tros makes a nice 3 lug but you are committed to it and I just prefered having open options
I used a Colt 9mm upper only because it lacked the gas tube hole, and the forward assist. A 7" rail on a 5" barrel has a real nice SD look to it.

Although you didn't ask Im going to add my 2 cents in case anyone needs it. There seems to be a lot of quirks to a 9mm AR but I did my research on others failures and seemed to have gotten it right. There is no gas tube so recoil (moreso suppressed) is a little harsher on the lower, and hammer. To slow it down, I went with a HeavyBuffers.com 9Q buffer and their heavier buffer spring. Also a ramped bolt won't beat up the hammers as much but will limit some some hammer choices. I found the POF drop in trigger works well with the ramped bolt (I didn't want a dedicated 9mm hammer). I have yet to try the Giessle SD3G trigger in to see if it will like the ramped bolt but hoping it will take it. It seems to be hit or miss on feedback out there.

LOWER: There are some Glock mag dedicated lowers but I went with a standard lower and a HAHN mag (top load) conversion.

Magazines: Promag brand sucked as I assumed it would but gave one a try. I attempted to convert an UZI mag via dremel and failed. I wound up going with C products magazines and all 7 performed flawless. (Stag arms magazines are rebranded by C-products also) I did however take the advice of a forum member and lightly sanded the contact points of the followers to smooth it out prior to the first run.

The only problem I encountered with the build was the magazine catch. This I found was a common complaint. Its supposed to accept a standard AR catch but I found it wasn't angled or canted inward enough to grab onto the magazine. I could pull magazines out with a slight wiggle. The solution was to dremel a 9mm mag catch (essentially the same as an AR catch and will still function with AR Mags) but it has a small bump by the post. I took off some that metal bump off the inside portion of it, making it lean inward enough. Works great now.

PS you can choose to go with a dedicated 9mm Bolt catch for a bolt hold open feature. I am fine without it holding open.
Last edited by Frank Castle on Wed Dec 16, 2015 11:09 pm, edited 1 time in total.

cyclone72
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Re: 9mm AR upper

Post by cyclone72 » Tue Oct 27, 2015 9:16 pm

Frank Castle wrote:I decided to make my own after looking at the options. Its a fairly easy build as it has no gas tube so go as short as you want. I went with an ADCO 5" barrel as they offer them with a 1/2x28 thread unlike others. I then went with a 3 lug and added Rocksett to keep it there. Tros makes a nice 3 lug but you are committed to it and I just prefered having open options
I used a Colt 9mm upper only because it lacked the gas tube hole, and the forward assist. A 7" rail on a 5" barrel has a real nice SD look to it.

Although you didn't ask Im going to add my 2 cents in case anyone needs it. There seems to be a lot of quirks to a 9mm AR but I did my research on others failures and seemed to have gotten it right. There is no gas tube so recoil (moreso suppressed) is a little harsher on the lower, and hammer. To slow it down, I went with a HeavyBuffers.com 9Q buffer and their heavier buffer spring. Also a ramped bolt won't beat up the hammers as much but will limit some some hammer choices. I found the POF drop in trigger works well with the ramped bolt (I didn't want a dedicated 9mm hammer). I have yet to try the Giessle SD3G trigger in to see if it will like the ramped bolt but hoping it will take it. It seems to be hit or miss on feedback out there.

LOWER: There are some Glock mag dedicated lowers but I went with a standard lower and a HAHN mag (top load) conversion.

Magazines: Promag brand sucked as I assumed it would but gave one a try. I attempted to convert an UZI mag via dremel and failed. I wound up going with C products magazines and all 7 performed flawless. (Stag arms magazines are rebranded by C-products also) I did however take the advice of a forum member and lightly sanded the contact points of the followers to smooth it out prior to the first run.

The only problem I encountered with the build was the magazine catch. This I found was a common complaint. Its supposed to accept a standard AR catch but I found it wasn't angled or canted inward enough to grab onto the magazine. I could pull magazines out with a slight wiggle. The solution was to dremel a 9mm mag catch (essentially the same as an AR catch and will still function with AR Mags) but it has a small bump by the post. I took off some that metal bump off the inside portion of it, making it lean inward enough. Works great now.

PS you can choose to go with a dedicated 9mm Bolt catch for a bolt hold open feature. I am fine without it holding open.
Wow, thanks! Lots of great info. So using a ramped bolt means you don't have to use a 9mm hammer? You can use the AR hammer already there? Thanks again for all the info. You pretty much answered all my future questions in one shot and now I can proceed with more confidence.

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Frank Castle
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Re: 9mm AR upper

Post by Frank Castle » Tue Oct 27, 2015 9:34 pm

Yes- a ramped bolt deletes the need for a rounded 9mm hammer but some enhanced triggers out there like a Giessle can be hit or miss with a ramped bolt. The POF drop in made by Timney works and comes with KNS trigger pins as a bonus. Forgot to mention that the non rotating hammer/trigger pins are recommended on this set up to lessen the chances of the trigger pin holes "egging out" turning oval and loose over time.

cyclone72
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Re: 9mm AR upper

Post by cyclone72 » Tue Oct 27, 2015 10:07 pm

Frank Castle wrote:Yes- a ramped bolt deletes the need for a rounded 9mm hammer but some enhanced triggers out there like a Giessle can be hit or miss with a ramped bolt. The POF drop in made by Timney works and comes with KNS trigger pins as a bonus. Forgot to mention that the non rotating hammer/trigger pins are recommended on this set up to lessen the chances of the trigger pin holes "egging out" turning oval and loose over time.
Thanks, looks like a plan for me to follow. Gonna check prices and availability.

noisecatcher
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Re: 9mm AR upper

Post by noisecatcher » Wed Dec 16, 2015 8:24 am

Ok Frank I need to see pictures of this 9mm build or it never happened. Jk but I would like to see it if you don't mind.

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Frank Castle
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Re: 9mm AR upper

Post by Frank Castle » Wed Dec 16, 2015 9:41 pm

Image
Manta Defense Tac Wrap on a 7" Key mod.
Last edited by Frank Castle on Wed Dec 16, 2015 11:16 pm, edited 3 times in total.

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T-Rex
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Re: 9mm AR upper

Post by T-Rex » Wed Dec 16, 2015 9:46 pm

Look into DI uppers as well.
They can run quieter and cleaner than blowback.

Nice Frank!
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Re: 9mm AR upper

Post by OJB4 » Fri Jan 08, 2016 3:54 pm

T-Rex wrote:Look into DI uppers as well.
They can run quieter and cleaner than blowback.

Nice Frank!

T-Rex.....Why is there never anything in the body of your replies? It's just a sexy as hell woman and something yellow (at least I think so) past her......I seriously can't function after I see your replies. Sure hope I'm not missing any important info you have to contribute since I can't ever see any typing on your replies.

Jay
I've gotta stop this habit.

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T-Rex
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Re: 9mm AR upper

Post by T-Rex » Fri Jan 08, 2016 7:24 pm

OJB4 wrote:It's just a sexy as hell woman
Jay
I have been told there is a car in there, but I've never found it :D
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Re: 9mm AR upper

Post by OJB4 » Mon Jan 18, 2016 3:00 pm

T-Rex wrote:
OJB4 wrote:It's just a sexy as hell woman
Jay
I have been told there is a car in there, but I've never found it :D
Must have been a woman that told you about the car....no man could possibly see such a thing.
I've gotta stop this habit.

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