Everyone builds AR15s, a bunch of us build AR9s. So a 9mm AR can be a bit of a rare thing. Most people have never heard of them. But they are fun as hell.
I started with a Polymer80 receiver that I bought with a lower parts kit, and buffer tube from Ghost Firearms down in Florida. Let me say that their customer service is excellent. I ordered the pistol kit when I should have ordered the rifle. A quick email got that ironed out in less than an hour. Package arrives and it is short the lower parts kit. A quick phone call and that issue was resolved in less than 4 days. Receiver received and waiting.
Next up, I took a few more weeks looking at uppers in 9mm, all different configurations. When I totaled all the parts still needed I came up with $600. Bummer right? Nope. I stumbled upon Karrisguns.com. A new 16 inch flat top upper, with the mag conversion kit I needed, plus a 7.5 oz all stainless steel buffer. Not, Karris had gotten a ton of bad reviews, most were up to 5 years old. But I decided to take the chance, the price was right at $399 with free shipping. In 3 days I had my new complete upper with 9mm BCG. No issues, no dings, scratches or anything. Picture perfect.
OK, time to mill the 80% lower from Polymer 80. The kit was missing it end mill bit. Again, no problem, contacted Polymer 80 and I had that bit in 2 days. Let me warn all of you, the polymer 80 kit has to be done the way the company tells you. Take your time, check everything twice before you start. You will also need to fit things, so if you like to tinker this is for you. Total time start to finish was 2.5 hours.
Yay! time to fit the LPK. Disconnect spring was out of spec, and a few other parts were MIA. To the gun show! Parts in hand, the LPK was installed with antiwalk dogbone pins. This was a 5 minute procedure. No biggie.
Ok now for something called the Trokmag G-block (takes glock mags). It requires you to install it in two pieces into the magwell, a metal one, because it twisted to the side when the set screws were tightened. Well hell, I thought I was going to need to get a metal lower. Nope. I sat on it for a few hours then decided to run a drill bit down the set screw shaft, make an indent for the set screw. 20 minutes later, the G-block was installed and tweaked. Next came modification of the glock mags. The company said to only use Glock OEM mags. Pfffft, not me, I modified a magpul one as well. I had to tweak the magpul mag a bit but it works flawlessly and at 1/3 the price.
I took my new girl to the range and started pumping lead downrange. She performed flawlessly except for a few light primer strikes, The rounds were loaded back into a magazine and all fired the second go around. I will be getting another Hammer spring and this should resolve the issue. Ammo used was all ball, from 20 years old to brand new. Everything from no name reloads to Federal and Wally world Winchester white box. Again a few issues with the rounds mentioned earlier. Groups came in at around 3 inches at 50 yards. As soon as I can download the pictures I will post them up.
Sights are Dagger Defense pop up iron sights co-witnessed with on Bushnell 30mm red dot that was lying in a junk pile in my basement.
So a few hicupps along the road to building this new rifle. Oddly I never lost my temper too bad. Just a lot of hurry up and wait. Expect to take your time on a build like this. You will have to tinker and repeat. This is not for the average Joe that knows nothing about the AR platform. The ability to troubleshoot is extremely important to make a ground up build go well.
Project total: $600
EDIT: Here are the pics. We aren't allowed to have mags in during a cease fire, or when we are not at the bench, so no pic of the gun with mags yet. My shooting partner was sick today so I did the best with what I was allowed.
I started with a Polymer80 receiver that I bought with a lower parts kit, and buffer tube from Ghost Firearms down in Florida. Let me say that their customer service is excellent. I ordered the pistol kit when I should have ordered the rifle. A quick email got that ironed out in less than an hour. Package arrives and it is short the lower parts kit. A quick phone call and that issue was resolved in less than 4 days. Receiver received and waiting.
Next up, I took a few more weeks looking at uppers in 9mm, all different configurations. When I totaled all the parts still needed I came up with $600. Bummer right? Nope. I stumbled upon Karrisguns.com. A new 16 inch flat top upper, with the mag conversion kit I needed, plus a 7.5 oz all stainless steel buffer. Not, Karris had gotten a ton of bad reviews, most were up to 5 years old. But I decided to take the chance, the price was right at $399 with free shipping. In 3 days I had my new complete upper with 9mm BCG. No issues, no dings, scratches or anything. Picture perfect.
OK, time to mill the 80% lower from Polymer 80. The kit was missing it end mill bit. Again, no problem, contacted Polymer 80 and I had that bit in 2 days. Let me warn all of you, the polymer 80 kit has to be done the way the company tells you. Take your time, check everything twice before you start. You will also need to fit things, so if you like to tinker this is for you. Total time start to finish was 2.5 hours.
Yay! time to fit the LPK. Disconnect spring was out of spec, and a few other parts were MIA. To the gun show! Parts in hand, the LPK was installed with antiwalk dogbone pins. This was a 5 minute procedure. No biggie.
Ok now for something called the Trokmag G-block (takes glock mags). It requires you to install it in two pieces into the magwell, a metal one, because it twisted to the side when the set screws were tightened. Well hell, I thought I was going to need to get a metal lower. Nope. I sat on it for a few hours then decided to run a drill bit down the set screw shaft, make an indent for the set screw. 20 minutes later, the G-block was installed and tweaked. Next came modification of the glock mags. The company said to only use Glock OEM mags. Pfffft, not me, I modified a magpul one as well. I had to tweak the magpul mag a bit but it works flawlessly and at 1/3 the price.
I took my new girl to the range and started pumping lead downrange. She performed flawlessly except for a few light primer strikes, The rounds were loaded back into a magazine and all fired the second go around. I will be getting another Hammer spring and this should resolve the issue. Ammo used was all ball, from 20 years old to brand new. Everything from no name reloads to Federal and Wally world Winchester white box. Again a few issues with the rounds mentioned earlier. Groups came in at around 3 inches at 50 yards. As soon as I can download the pictures I will post them up.
Sights are Dagger Defense pop up iron sights co-witnessed with on Bushnell 30mm red dot that was lying in a junk pile in my basement.
So a few hicupps along the road to building this new rifle. Oddly I never lost my temper too bad. Just a lot of hurry up and wait. Expect to take your time on a build like this. You will have to tinker and repeat. This is not for the average Joe that knows nothing about the AR platform. The ability to troubleshoot is extremely important to make a ground up build go well.
Project total: $600
EDIT: Here are the pics. We aren't allowed to have mags in during a cease fire, or when we are not at the bench, so no pic of the gun with mags yet. My shooting partner was sick today so I did the best with what I was allowed.