I've got a couple of the older B models. One started life as a 10T. GAP made it different with a Schneider barrel. It's like 19-20 years old n still ticking...
One started as an A4. It wears a kreiger barrel now. Looks like the Gap twin. Both of the have been used hard. Both got carried as working guns at the pd.
One B series started as parts off ARF-Com... it's got a Kreiger barrel too, and its probably killed 500 pigs.
They were like, heavy.... I took them apart and we turned the fat assed barrels down for two and three pound weight losses. Put them back together. Two went back with no zero change, one shifted a half moa....
Later, one got the DD light handguard snatched off and a midwest Industries rail added. No zero change. Still killing pigs.
They are still, like, heavy..... there isn't much left I can reduce and be personally happy.... and they all use metal mags. However....
There were three more early variants that passed through my hands, that now reside as issued at friends houses, who come help me kill pigs...
All of them worked fine, first time, every time, and still do.
I mentioned they were all, like, heavy...
Armalite NOW sells a super light A series hunting defense 16" carbine (chrome lined), that uses pmags. It's got a pencil barrel.
A couple of them drifted through my hands a year ago and about a year ago. Both got the plastic handguard taken off and the factory gas block, and got Midwest Industries handguards added and whatever adjustable gas block I could scrounge. I run a 130 hollow point reload out of them that might be scary to some people, in pulled down crimped primer military brass. The adjustable block helps tame the nuclear load.
They kill the hell out of pigs, both have killed a hundred or so.
Zero problems, b4 the mods with factory ammo, zero after. All I've added to the extractors is a rubber o' ring like the defender D ring m4 extractor mod. All my ars wear o' rings on the extractor spring.
And then...... I had found a Gun Broker take down pencil barrel off one of the A series guns, and bought it. The two A's shot so well killing pigs, that I couldn't resist the price on a pencil barrel the seller never fired, him having bought the armalite to build on.
My old sniper partner wanted to kill some pigs, with a lighter gun.... so... I pulled the kreiger barrel B series down and stuck the A series barrel in it, and he went and killed pigs...
I walked by that taken off kreiger barrel a few months and wanted to put it back to work..... I looked high and low for a B upper to put it on. I can find moon dust and bit coin, but no B series uppers to put the barrel back into.... I had friends looking. Lots of friends in lots of places... we could find small rifle primers easier than a B series upper......
I was beginning to despair..... badly...
Then, I found this A series kit upper/lower (Matrix) on Gunbroker for sale and asked here on line if anybody knew about them.
@sinister was familiar with them... another friend had a set in hand and said, "try these b4 u buy off GB"...
I took the receiver/lower kit, brownells bolt, Aero lower parts kit, Guntech upper kit, the Armalite pencil barrel back from my Sniper partner, an old taken off DD rail, and some more Armalite stock parts, and in about an hour.... see pic..
It function tested just fine when I tried to kill it. The pencil barrel shoots as good as it did b4 in the B series A4 build. It's a sub moa pig killer. Now back in my Sniper partners hands.....
The kreiger is back on the A4 built gun. Back to work...
I have pig hunters with LAR, DPMS, RR, DD, and a KAC. We have shot the shit out of them. The older DPMS had some soft parts like bolt stops and mag catches. The KAC lost a couple of bolt stops. The rest have run just fine on the factory parts. A few come overgassed and we swap to adjustable gas blocks and dont look back.
We have had a few lemons by all the factory guns, and more hummers than lemons. All shot GOOD ammo sub moa with average out of the box guns shooting .75 to 1moa consistently.
Then, there were these lots of 118LR that got sold to the public, that shoot like shit, no matter what platform we shoot it in.
And there is other dogshit ammo out there being sold that will make you sell your big bore AR because you will be convinced something is wrong with the gun. Most of the time, it's not the gun, it's the ammo.
That's my life with the Armalites, and experiences with others, to date.
Best to you.