AR9 decisions...

Tucci454

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I've been thinking of doing an AR9 for a while, but they're kind of cost prohibitive. However, I picked up a PSA upper here on the classifieds for a decent price so I'm all in now.

Now I'm trying to figure out what to do about the lower. I think I want Colt mag, primarily because it looks better. The operational lrbho would be nice too.

Finding a Colt lower at a reasonable price is proving difficult. I'm considering a regular lower with a KAK mag well adapter. Other people seem to like those adapters. I figure I'll be into it for close to the same money as a Glock lower after getting a new buffer and if I hate it, I can always pull the adapter and just get another rifle upper.

I've been looking at the posts over there at arfcom, and those guys seem to be all over the place on this stuff.

Anyone have more experience with these things and provide some useful advice?
 
I do not have a KAK magwell adapter but do have three AR-9s with PSA Colt-style magwell adapters and they all work well. I can't imagine the KAKs would be anything less?
 
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I have a PSA colt adapter that has worked perfectly for me over several thousand rounds. Before that, I had a Hahn insert that was just as good.
 
Id go with a Glock lower as well. I did and have no regrets. New Frontier Armory has a LRBHO
 
I've been thinking of doing an AR9 for a while, but they're kind of cost prohibitive. However, I picked up a PSA upper here on the classifieds for a decent price so I'm all in now.

Now I'm trying to figure out what to do about the lower. I think I want Colt mag, primarily because it looks better. The operational lrbho would be nice too.

Finding a Colt lower at a reasonable price is proving difficult. I'm considering a regular lower with a KAK mag well adapter. Other people seem to like those adapters. I figure I'll be into it for close to the same money as a Glock lower after getting a new buffer and if I hate it, I can always pull the adapter and just get another rifle upper.

I've been looking at the posts over there at arfcom, and those guys seem to be all over the place on this stuff.

Anyone have more experience with these things and provide some useful advice?
I have a very nice ar9 I’m thinking about selling pm me if interested
 
I bought the cheapest adapter I could find. ProMag. It works, put a thousand thru it quick and have slowly added maybe 500 since. Mags took some tuning.

If I did it again, I'd probably go with a Glock mag lower but I'd probably run it in matches. I think that they may feed more directly into the chamber as well, mine beats beats pretty hard.
 
I went with the adapter because my lower is an SBR. I wanted the option of reverting back to 'whatever' caliber if I wanted. Though, with Form 1s processing so quick these days, it would be less of a concern these days.
 
My opinion:
Does not look better. At all. Looks goofy.

edit: arfcom: mostly 20 somethings without a clue parroting what garandthumb said yesterday.

Get a decent glock lower

Edit: Ignore me. I’ve been drinking.
 
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It’s just my opinion, but I think the Glock mag lowers look even dumber than the Colt mag lowers.

I have two that take Colt mags. One has a Hahn dedicated mag block, and the other is a CMMG lower designed for the mags, no adapter needed. Both have LRBHO.
 
It’s just my opinion, but I think the Glock mag lowers look even dumber than the Colt mag lowers.

I have two that take Colt mags. One has a Hahn dedicated mag block, and the other is a CMMG lower designed for the mags, no adapter needed. Both have LRBHO.
I agree on the looks. They're both goofy, straight mag slightly less.

Quick search shows some Glock adapter with LRBHO.
 
I prefer the look of the Glock lower.

also have a couple pistol barrels, already threaded, if you’re shopping for one.
 
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It’s just my opinion, but I think the Glock mag lowers look even dumber than the Colt mag lowers.

I have two that take Colt mags. One has a Hahn dedicated mag block, and the other is a CMMG lower designed for the mags, no adapter needed. Both have LRBHO.

Yeah, they both look kind of stupid. I think the dedicated lowers look less stupid than the blocked lowers. Not by much though. I'm probably going to grab one of those mag conversions and a heavy buffer just so I can try it out. I'm hesitant to drop another $300 into this thing only to find out I hate it. I know I'm going to be stuck with it because no one is going to want to buy my cobbled together firearm.
 
Yeah, they both look kind of stupid. I think the dedicated lowers look less stupid than the blocked lowers. Not by much though. I'm probably going to grab one of those mag conversions and a heavy buffer just so I can try it out. I'm hesitant to drop another $300 into this thing only to find out I hate it. I know I'm going to be stuck with it because no one is going to want to buy my cobbled together firearm.

In addition to dropping $300, you'll want to drop some quarters. Specifically, into the buffer tube.

As many as you can and still have the bolt lock back. My AR9s came with longer buffers specifically for the AR9 so I only needed three quarters in each but some people have said they needed as many as eight.

Sure, you can buy custom spacers but they are like five or ten bucks each. I was able to buy three quarters for only $0.75.

edit - and as for the cosmetics: once the block is in it looks just like a regular AR lower except when looking directly in the magwell.
 
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As many as you can and still have the bolt lock back. My AR9s came with longer buffers specifically for the AR9 so I only needed three quarters in each but some people have said they needed as many as eight.
I’ve seen this mentioned before but have never attempted it. Does that simply mean manually locking the bolt back? Or having LRBHO still function? Is it necessary to have a loaded mag (snap caps if you prefer) to make sure you don’t have too many quarters?

Just trying to figure out if it’s something I can mess with at home. I know it’s to prevent damaging the lower and breaking the bolt catch.
 
I grabbed an empty mag and checked both LRBHO and manually locking the bolt back while at home. With three quarters everything tested flawlessly but with four the bolt wouldn't always catch. So three seemed like the right number for the buffers PSA supplied.

In use at the range, all three AR9s with three quarters each have been flawless as far as LRBHO and manually locking the bolt back goes.

edited for clarity
 
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Have you actually shot one? You’re a looooong way from me or I’d be glad to let you try one/both of my lowers with your upper.


Here’s what the CMMG looks like. Standard size magwell on the outside, just machined for a colt mag on the inside. So, no better looking that the others, just one less piece to buy and fool with. I got this one when they put them on sale for $99 sometime in the last year or so. Finally assembled everything a month or two ago.

View attachment 170257

I have not tried one yet. As far as the appearance goes, I guess it's really not that important. I like the look of the PSA Colt mag version. Also the Spikes version, with the exception of the funny looking trigger guard on that one. The material in front of the mag well apparently offends me.

Then there's the MP5 mag version from New Frontier. That is really pretty and the long mags are even curved a little. That wouldn't work with the upper I bought though, so more bucks in machine work to go that route.
 
Yeah, they both look kind of stupid. I think the dedicated lowers look less stupid than the blocked lowers. Not by much though. I'm probably going to grab one of those mag conversions and a heavy buffer just so I can try it out. I'm hesitant to drop another $300 into this thing only to find out I hate it. I know I'm going to be stuck with it because no one is going to want to buy my cobbled together firearm.
If you like shooting and you get it to run reliably it is highly unlikely you won't like it. Quiet, cheap to feed, easy on closer steel targets, still pretty capable on paper/steel at 200yds, same operations and skills as any other AR.
 
Sober opinion: I do agree a lot of AR9's do look stupid. I swear mine shoots great but it is undoubtably my ugliest gun, and I have plenty of ugly guns, including three hideous grocks.

It's a butterface for sure, and I intend to ugly-it-up some more with a 15" carbon fiber handguard, when I stop being lazy. Even the trigger is ugly.

IMG_3467.jpg
 
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Between the different barrels, silencers and stock/brace, there’s about a 7” difference in mine. (3” for barrel, a little over 2” for silencer, and the rest in the stock/brace)

4D6F1C06-B0F1-4360-A704-4BC294B25427.jpeg
 
I grabbed an empty mag and checked both LRBHO and manually locking the bolt back while at home. With three quarters everything tested flawlessly but with four the bolt wouldn't always catch. So three seemed like the right number for the buffers PSA supplied.

In use at the range, all three AR9s with three quarters each have been flawless as far as LRBHO and manually locking the bolt back goes.
Tried it today with the 4” pistol. Could only get one quarter in there and still have the bolt lock back. Guess the longer/heavier buffer from PSA is doing the job.

Didn’t try it with the SBR, as it’s my primary HD choice and I’ll wait until I’m at the range. I’m guessing it’ll be about the same since it has a Hahn pistol caliber buffer.
 
Endomag came today. Looks kinda cheap, but was a snap to install and seems to work good with a manual function check. Put the big buffer in, 3 quarters for this one too. We'll see what happens at the range. Hopefully it will run OK like this so I can just buy a cheap lower and be done with it.
 
Finally got a chance to run this thing. Ran it at the indoor range, I think it's 40 yards, but I wasn't really paying attention. Ran almost perfectly, one FTF(eed) I put 200 through it or so. LRBHO does not work, but it's not the fault of the Endomag. Either the catch is a little too short or there is not enough material on the bolt. If you manually engage the catch an set the rifle down hard, the bolt returns to battery. I can look in there and see it barely catching the bolt. Recoil is a bit more than I anticipated. I'm going to try some heavier buffers I guess. By the way, laugh all you want on my Amazon optic, but that thing is tough as nails.

All in all, I'm very happy with it. I'm into it for right at $440, including the FFL.59736149804__B9F76233-3166-4F9B-9D2A-4CC55A36E8E7.JPG
 
Here's the two 5 shot groups after I got got done screwing around. Edit: it was 10
shots in the 8 ring IMG_0004.JPEG
 
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... Recoil is a bit more than I anticipated. ...

IME, blowback ARs have about the same overall recoil as regular ARs (although the quality of the recoil differs).

I've never shot one of the direct impingement pistol-caliber AR platforms but have heard they have less recoil.
 
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IME, blowback ARs have about the same overall recoil as regular ARs (although the quality of the recoil differs).

I've never shot one of the direct impingement pistol-caliber AR platforms but have heard they have less recoil.

A friend of mine likes to build pistols, so he has some buffers laying around that I can play with. Worth a shot. The recoil isn't really terrible, but it will sting your cheek pretty good if your weld is a little weak.
 
I sold both my AR9 builds one colt and other Glock. I’m picking up my akv tomorrow I’ll post pictures when I get it home I’m so excited just wanted something different. Woooooooo
 
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