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Posted: 12/18/2025 5:51:10 PM EDT
Here's my Brownells BRN180 lower receiver which I've started assembly on. I screwed up and lost the set screw that holds in place the spring for the rear takedown pin's detent and am waiting for my replacement setscrew [a 4-40x.125"] to arrive in the mail. The detent relief hole is drilled in vertically instead of horizontally like on the AR15 because the BRN180 uses a detachable folding stock.  
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Here's my Midwest Industries side folding stock I'll put on my build once I get all of my lower receiver parts assembled. It's designed so that the shooter can make it fold to either the left or right side and if folded to the right you can still fire the rifle without the stock interfering with the ejected cases.
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| I like the looks of the Midwest stock. I bought a Sig on sale before I had seen the Midwest. I still regret not grabbing one or two of the Brownells stocks when they blew them out for $50. |
BikerNut:
Normal people like motorcycles. Real people like motorcycles.
People who don't like motorcycles are just... weird.
Normal people like motorcycles. Real people like motorcycles.
People who don't like motorcycles are just... weird.
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Originally Posted By User55645: Std lower w/ 180 upper. I went w/ the Lage folder and made my own custom mount to reduce unnecessary length and parts. https://i.ibb.co/kKwHPcF/BRN-180.jpg I had an Armalite 180 back in the day and sold it. It was piercing primers on my dad's reloads and being young, thought it had something to do with the gun. Being frugal, my dad probably used pistol primers because he had some of those available...  I couldn't shoot that rifle very well, so I wasn't sad to let it go at the time. Now, I wish I'd kept it. |
The BRN180 Gen. 3 Upper Receiver, Left Side View. The 3 flat head socket head screws hold the steel cam pin track in place. The cocking lever is angled downward a few degrees which is a good idea. If it's up too high, sometimes the shooter will skin his fingers on the optics mounting hardware. Guys, how do I change my icon? The Moderator hasn't answered my requests! |
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Originally Posted By Blowout: Can you take a pic of the other side and post it? Like to see what the charging handle looks like. I had an Armalite 180 back in the day and sold it. It was piercing primers on my dad's reloads and being young, thought it had something to do with the gun. Being frugal, my dad probably used pistol primers because he had some of those available... I couldn't shoot that rifle very well, so I wasn't sad to let it go at the time. Now, I wish I'd kept it. Charging handle is similar to the -180, depending on your optic/mount it can be an issue - Slim optic/mount or work it like an AK and it's not a big deal. Here's a gen 2.5 10.5" 5.56 180s upper I recently acquired  For the OP, enjoy the new build - post over in this thread when you're finished too  I'm a big fan of the BRN-180, got a few of the uppers and they are nice smooth shooters and great suppressor hosts |
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Got 'er Done! Final Assembly completed! The assembly of the rear takedown pin detent was the hardest part of this project! My mechanic managed to loose my detent spring. It went flying across the shop to G*d only knows where. Fortunately, I had a spare spring. We finally ended up installing the detent, it's spring and it's setscrew but then we found that the detent was bottoming out the spring when it was depressed and wouldn't fully compress below the takedown pin clearance so I had to bob about .125" [1/8"] of one end of the detent spring so the detent would properly compress. We had to use a slave pin to insert the takedown pin after the detent was properly compressed but that did it. All that remained then was assembly of the safety, the safety detent and it's spring and the tightening down of the pistol grip screw. It got dark on us so I wasn't able to go out and do a test fire. 
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Originally Posted By stiglitz_actual: Charging handle is similar to the -180, depending on your optic/mount it can be an issue - Slim optic/mount or work it like an AK and it's not a big deal. Here's a gen 2.5 10.5" 5.56 180s upper I recently acquired https://distortion.io/i/IMG_2003.jpg That handle looks like I remember on the AR180. It was made of bent steel rod if I remember correctly. |
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Originally Posted By Redbeard2: The BRN180 Gen. 3 Upper Receiver, Left Side View. The 3 flat head socket head screws hold the steel cam pin track in place. The cocking lever is angled downward a few degrees which is a good idea. If it's up too high, sometimes the shooter will skin his fingers on the optics mounting hardware. Guys, how do I change my icon? The Moderator hasn't answered my requests! https://i.imgur.com/xz39Lkl.jpeg As far as changing your avatar/icon I think you have to be paid member. I believe paid members have a gold star next to their user name and can add a Avatar or Icon which shows up in the blank square next to the user name. |
US GI replica cotton sling, most likely made in China. The hardware on it is epoxy coated not parkerized like the original GI units. I messed up installing the sling and it's hardware. It's on the left side and I should have installed it on the right side. The charging handle will most likely be digging into my back!
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HK style sling hook attached to a rail mounted sling adapter. You can see the .223 Wylde engraved on the barrel. The .223 Wylde caliber has the exact same chamber dimensions as the .223 Rem. and the 5.56 NATO with a slightly longer throat before the bullet engages the rifling. https://en.wikipedia.org/wiki/.223_Wylde_chamber
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I installed some M-Lock Picatinny rails on the handguard, 1 13 slotter on the botton and 2 11 slottters on each side. The 13 slotter was a polymer which I wouldn't have ordered but I didn't read all the small print. I'm going to run it anyway. I need these rails so I can run some polymer rail covers. These aluminum handguards get really hot, especially after doing several rapid fire mag dumps with your AR. As a retired tool & diemaker I tend to prefer aluminum over polymer but I realize that with so many of these polymer rails on the market they can't be that bad.
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EDL asked: "Why are the BRN uppers/receivers so expensive compared to a std receiver/upper?" Because they come with an assembled barrel, bolt and bolt carrier, recoil system, gas system, and handguard. The Gen 3s are going for $1139.99. https://www.brownells.com/gun-parts/rifle-parts/rifle-receivers-parts/brn-180-gen-3-223-wylde-16-complete-upper-receiver-assembly/ |
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