AR pistol with fixed Mag? (In mass )

At the risk of asking the question that has likely been answered many times before...

If you go with the 10 round fixed mag lower, does that mean you don't have to worry about AWB as far as the other features? My reading is that AWB requires removable mag. Could you do fixed mag and an upper with bayonet lug, threaded barrel, and adjustable/folding stock?
 
Yea to be clear I am not willing to go with just the MA lock. these are going to be full featured guns (Ar pistol and ar10 rifle) I am considering. If you go with a plastic/polymer Mag and they can be easily removed then No bueno. (But I have a small machine shop to work on my toys. )
 
At the risk of asking the question that has likely been answered many times before...

If you go with the 10 round fixed mag lower, does that mean you don't have to worry about AWB as far as the other features? My reading is that AWB requires removable mag. Could you do fixed mag and an upper with bayonet lug, threaded barrel, and adjustable/folding stock?

You are correct. as long as it is permanently affixed before the receiver is completed you should be fine.
 
It is a definite fascinating in-the-middle-of-no-man's-land sort of frankengun.

Consider this:

You put a flash hider that's really a muzzle brake on it.

You put one of those adjustable Gen3 SB Tac arm braces on. Uses a 5-position stock and adjusts accordingly.

10.5 or 11.5 bbl on there.

BUT. . . . fixed mag.

I'm not sure what the dealio would be when Herr Healy gets federally smacked down on this and the 7/20 regulation dies. You pull the restrictor parts from the AR, put in a conventional mag release and. . . . is the adjustable arm brace still legal???? I mean, it's an arm brace, not a stock. So adjustment is moot, right? So you'd need to ensure you have the brake/hider permanently installed.

And yes, I'm amassing some parts to build one of these. I find it fascinating.
 
You are correct. as long as it is permanently affixed before the receiver is completed you should be fine.

In MA, as long as it's attached before a shop sells you a post-7/20 receiver in the first place. I think. If I could go and get a stripped non-anything'd lower right now, I'd be all over that.
 
Well if you pull the fixed mag it is then an over 50 oz pistol (with the short barrel) and removable mag so no good from just the AWB no matter healy.

The primary reason for me anyway is to have a non- AWB AR pistol.

It is a definite fascinating in-the-middle-of-no-man's-land sort of frankengun.

Consider this:

You put a flash hider that's really a muzzle brake on it.

You put one of those adjustable Gen3 SB Tac arm braces on. Uses a 5-position stock and adjusts accordingly.

10.5 or 11.5 bbl on there.

BUT. . . . fixed mag.

I'm not sure what the dealio would be when Herr Healy gets federally smacked down on this and the 7/20 regulation dies. You pull the restrictor parts from the AR, put in a conventional mag release and. . . . is the adjustable arm brace still legal???? I mean, it's an arm brace, not a stock. So adjustment is moot, right? So you'd need to ensure you have the brake/hider permanently installed.

And yes, I'm amassing some parts to build one of these. I find it fascinating.
 
Damn. I hadn't thought of that. Fixed-mag forever! That's fine. If I need more than 10 rds of .223 to repel boarders at the in MA Castle, I'm doing something wrong. LOL

Stupid AWB. Really really stupid.
 
Has anyone used the fixed mag loader?
Yeah I have them for my fixed mag pistol. They're not as easy to use as shown in those vids, especially with a new magazine. It takes alot of pressure to get all ten rounds into the mag. (think laying the gun on the bench and using two hands kinda pressure).
The more rounds the easier its getting, I'm still two handing it though. Leaving the mag loaded while stored seems to be helping to soften up the spring also.

I also game across This Loader, same idea prob same issue with stiff mags but I might get one to give it a try.
 
Last edited:
That^^^^ definitely looks appealing, fixed mag and all.

I unsuccessfully tried to link a post from Steve’s tactical, looks like they have almost the same build for sale. Currently taking preorders.
 
Did you find your take down pin to be next to impossible to push? I think mine may be out of spec unfortunately.

I assemble a modest number of ARs each month. I occasionally see issues with the upper holes being out of spec by a few 1000ths. It has always been the upper when I measure things. I end up milling the upper, front takedown hole, inside side of hole, extending it 4-5 1000ths. The upper then fits perfectly on multiple different lowers.

I’ve seen this with multiple “brands” of uppers but likely all made by the same machine shop under contract. They usually have the same maker mark on them. I have only seen this when using complete uppers a customer specifically wanted. When I build uppers I have never had spec issues (I use Anderson uppers).
 
I assemble a modest number of ARs each month. I occasionally see issues with the upper holes being out of spec by a few 1000ths. It has always been the upper when I measure things. I end up milling the upper, front takedown hole, inside side of hole, extending it 4-5 1000ths. The upper then fits perfectly on multiple different lowers.

I’ve seen this with multiple “brands” of uppers but likely all made by the same machine shop under contract. They usually have the same maker mark on them. I have only seen this when using complete uppers a customer specifically wanted. When I build uppers I have never had spec issues (I use Anderson uppers).

Upper is not even her yet. Having a hard time just pushing the take down pin through the lower (we have the same one).
 
I can only imagine what it's like to reload that. Without using that weird speedloader, Pop the upper and then start pushing cartridges down. Is it awkward to hold when you do that with the gun in an almost T like position?
 
I may first just trying getting a new set of pins to see if that works. The pivot pin is fine so that would make me believe that the pin is what is wrong.

Heres mine so far:
JC Arms lower, MagPul MOE grip, BCM pistol tube, and SB Tactical SB-Mini Brace, and haven't decided on a trigger guard yet.

Lower.jpg
 
If the retaining pins That press on the takedown pins are a little sharp they will hold the pin in place with a lot of extra force, you can round the ends of the pin some to help, On my fixed mag gun I used some extended takedown pins and they where catching a bit until I moved them in and out a few dozen times. (not the same brand of lower as you guys.)
 
If the retaining pins That press on the takedown pins are a little sharp they will hold the pin in place with a lot of extra force, you can round the ends of the pin some to help, On my fixed mag gun I used some extended takedown pins and they where catching a bit until I moved them in and out a few dozen times. (not the same brand of lower as you guys.)

Yeah, I've had trouble with selector detents before. They wear in after flipping the selector back and forth for awhile.
 
I may first just trying getting a new set of pins to see if that works. The pivot pin is fine so that would make me believe that the pin is what is wrong.

Heres mine so far:
JC Arms lower, MagPul MOE grip, BCM pistol tube, and SB Tactical SB-Mini Brace, and haven't decided on a trigger guard yet.
Yeah that looks good I like the smaller brace. I've been looking at the SB Tactical braces they have some nice ones but I had already bought the Sig.

What upper did you go with??
 
Yeah I have them for my fixed mag pistol. They're not as easy to use as shown in those vids, especially with a new magazine. It takes alot of pressure to get all ten rounds into the mag. (think laying the gun on the bench and using two hands kinda pressure).
The more rounds the easier its getting, I'm still two handing it though. Leaving the mag loaded while stored seems to be helping to soften up the spring also.

Springs weaken from repeated use, going from fully loaded to unloaded. Not resting in a single state. Leaving it stored loaded does nothing useful for you.

Load/Unload it a few dozen times and it will break the spring in and it'll be easier.
 
Can someone remind me why using a preban 30rd mag in these builds is no good? What's the problem with the finished product being large capacity?
 
Back
Top Bottom