AR pistol with fixed Mag? (In mass )

Even with a 16inch barrel?

That makes it a rifle.... Stock with a 16" barrel is fine if you originally 4473'd it as a pistol or other. If other, if you go to rifle configuration first, a rifle it must stay.

Any barrel shorter than 16" would make it an SBR if you put a stock on it. That requires a $200 tax stamp from the ATF. Waste of money on a fixed mag lower.

This is federal nonsense, not MA nonsense. Just make sure you hate the right .gov entity for it.
 
AR9 just about finished. Just need to fix the 10 rounder and get an rds on there. I’m really liking the bronze and black. Stuck a preban fun stick in for pics. Would love to do it but making a post ban new build with high cap would be orangemanbad.

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Is this really good in ma? Might have to do the same to my build 😮
 
Is this really good in ma? Might have to do the same to my build 😮
Its only good if a 10 round mag is fixed via drill/tap with a set screw to restrict the mag catch/release from movement keeping the 10 round mag from being detached. Again, fixed mag is key for legality in Ma. But as you know even things that are legal in Ma are illegal. Gotta love this state!
 
Ran it today and it was flawless! What a sweet pistol. I have to makeshift some compression device to reload from the top. I can get about 6 rounds in before it gets tough. Removing floorplates off a glock mag is downright madness.
 

View: https://youtu.be/vsP3Zl6Ouho



View: https://youtu.be/y9jAFSr-odo


I tried testing G19 pmags beforehand but those are even tougher. I’m thinking a small open ended wrench would work pretty good by pushing down on the round to get as close to 10 in there as possible. Top loading is by far the best option in this case vs popping floor plates off. On my 5.56 pmags that is not an issue but over time they will get chewed up. Man, I hate this state.👿
 
Its only good if a 10 round mag is fixed via drill/tap with a set screw to restrict the mag catch/release from movement keeping the 10 round mag from being detached. Again, fixed mag is key for legality in Ma. But as you know even things that are legal in Ma are illegal. Gotta love this state!

Theoretically speaking, if someone found an AR9 lower in an MA store in recent years and built it to a working rifle, registered and everything, it would have to have a fixed 9mm mag? I assumed 9mm was exempt from that nonsense because its operating system was blowback, so not a copy. Also (maybe wrongfully) assumed that if a lower was being sold without a pinned mag, it was kosher.

And to those that know the correct answer, I'm sorry to continually beat this here horse, but MA is confusing. Some might even say purposefully so.
 
Theoretically speaking, if someone found an AR9 lower in an MA store in recent years and built it to a working rifle, registered and everything, it would have to have a fixed 9mm mag? I assumed 9mm was exempt from that nonsense because its operating system was blowback, so not a copy. Also (maybe wrongfully) assumed that if a lower was being sold without a pinned mag, it was kosher.

And to those that know the correct answer, I'm sorry to continually beat this here horse, but MA is confusing. Some might even say purposefully so.
Registered as a rifle.. All the AWB still apply. But no fixed mag is required. Just use 10 round mags or pre bans.

When you said recent years.. Was it bought after 07/16 or before?
 
Registered as a rifle.. All the AWB still apply. But no fixed mag is required. Just use 10 round mags or pre bans.

When you said recent years.. Was it bought after 07/16 or before?

Got it--thank you. Registered as a rifle / purchased some time last year. Didn't immediately notice the pistol brace on that build I was quoting. Got the 10rd mags and a couple pre-bans.

Damn this state--always making me second guess myself!
 
It's a maze of overlapping and confusing rules and laws. If you're going to go with a very-short braced 9mm pistol, you may be better off buying an MPX (or whatever they're called) and a dedicated G17. For $650 you're done. Or use your current gun (G17 or 19 or 22 or 23) with the chassis. And even more compact than an AR9.
 
It's a maze of overlapping and confusing rules and laws. If you're going to go with a very-short braced 9mm pistol, you may be better off buying an MPX (or whatever they're called) and a dedicated G17. For $650 you're done.
A MPX for $650?! Where are you finding them that cheap?! They're approaching like $2k
 
Got it--thank you. Registered as a rifle / purchased some time last year. Didn't immediately notice the pistol brace on that build I was quoting. Got the 10rd mags and a couple pre-bans.

Damn this state--always making me second guess myself!

The general consensus is that AR-9s operate on a different principal from AR-15s so the Healey ban does not apply. Abide by the AWB stipulations for a rifle and you don't need to fix the mag.
 
I have not and any preban lowers in 9mm you may come across like Colt go for the price of a pregnant unicorn.
 
The general consensus is that AR-9s operate on a different principal from AR-15s so the Healey ban does not apply. Abide by the AWB stipulations for a rifle and you don't need to fix the mag.
Unfortunately for the semi-auto pistol we can’t have beautiful things without chastity belts.
 
Sorry should have explained, I would be going the SBR route. I have the Stern Defense adapter which works great. Just a pain swapping back and forth.
 
Sorry should have explained, I would be going the SBR route. I have the Stern Defense adapter which works great. Just a pain swapping back and forth.

How's the LRBHO working on that Stern? LRBHO seems to be kind of a wonky afterthought in most Glock mag AR9's, so I was curious how they work in the Stern.
 
I finally got my FM9 to the range. It's an FM upper on an Aero lower, using an Endomag. It runs tit. Loading is as easy as it can be in a fixed mag configuration - the Endomag loads similarly to a standard rifle mag. Just press the rounds down in. I experienced no issues while resting the pistol on the magazine, as some users of Endomags reported. I did only load 9 rounds at a time, as getting the upper/bolt into place with 10 was problematic.

I slapped a trs25 rds on it, and had some fun @ 50 yards. I plan to run some quality ammo through it with a better sight, to verify precision.
 
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I finally got my FM9 to the range. It's an FM upper on an Aero lower, using an Endomag. It runs tit. Loading is as easy as it can be in a fixed mag configuration - the Endomag loads similarly to a standard rifle mag. Just press the rounds down in. I experienced no issues while resting the pistol on the magazine, as some users of Endomags reported. I did only load 9 rounds at a time, as getting the upper/bolt into place with 10 was problematic.

I slapped a trs25 rds on it, and had some fun @ 50 yards. I plan to run some quality ammo through it with a better sight, to verify precision.

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How much were you into that build? I heard the full Foxtrot is about $700 from Primary arms. I wound up spending about $800 not including the optic.
 
How much were you into that build? I heard the full Foxtrot is about $700 from Primary arms. I wound up spending about $800 not including the optic.
The FM upper was $319, FM 9mm tube/buffer $59, cheap brace $29, Aero blem lower about $45. The Endomag was nearly $40. The Endomag worked well enough that I'm thinking of getting an FM 9 carbine upper.
 
A MPX for $650?! Where are you finding them that cheap?! They're approaching like $2k

No. Not the Sig MPX. That chassis for the Glock Gen 3-5 frames. MCK. LOL.

It was 3 letters starting with M. It's about $200. Another $400-450 or so for a Glock. Instant SBR-style item. Brace. No mag well in front of the grip. VERY compact. Well designed. For the price, it's actually not that big of a deal to buy a dedicated pistol for the thing.
 
No. Not the Sig MPX. That chassis for the Glock Gen 3-5 frames. MCK. LOL.

It was 3 letters starting with M. It's about $200. Another $400-450 or so for a Glock. Instant SBR-style item. Brace. No mag well in front of the grip. VERY compact. Well designed. For the price, it's actually not that big of a deal to buy a dedicated pistol for the thing.
Like the RONI?
 
Like the RONI?

Or in the case of a MAC10, a Mac-A-Roni. Extremely dumb idea, but really good name.

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Yes. Roni is 1Gen. MCK or whatever is 2ndGen. Seems cheap for the PCC option with a short bbl.
Idk. The carbine frames for glocks’n’things seem cool but honestly might lack that umpff that AR9 pistols give.
 
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I think most problems with AR9's on YouTube is people trying to use hollow point ammo and they get jammed on the feed ramp. Most times they run great on cheap FMJ.

Idk. The carbine frames for glocks’n’things seem cool but honestly might lack that umpff that AR9 pistols give. I was tickled to be shooting that thing the other day and another NES’r who tried out my build as well as my 5.56 and x39 pistol liked the 9mm pistol the best. Put a smile on his face and immediately he was looking into maybe getting the gen 2 jig to build one. For the money you can build one in the same price range than what a G17 in a carbine frame would cost. Two totally different guns of course with blowback being the biggest factor for the AR9. I cannot speak to a full sized version with a 16” barrel since I never shot one.

I would say I was happy that claims for AR9’s being “wonky” or “unreliable” was put to task. Let me put 1k more rounds through it to confirm for sure.
 
I think most problems with AR9's on YouTube is people trying to use hollow point ammo and they get jammed on the feed ramp. Most times they run great on cheap FMJ.
Due to cost I just wouldnt run that kind or volume jhp’s through it. I ran 2 full mags of 115 gr and 124 gr federal jhp’s with no issues. Looking closely at the feed ramp while building it it appeared that could be an issue depending on how aggressive various 9mm defensive rounds can be.
 
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