I'm thinking of building a Glock mag PCC, or two (9 and 10mm maybe) and am looking for anyone who has experience with New Frontier Armory's lowers to chime in on their experiences. Are they decent products? They seem to be the best price. Also, are they compatible with any upper, or do I need to purchase their upper with it? Thanks guys.

I have built Glock System AR9's with...

Joe Bobs / NFA
PSA
Foxtrot Mikes.

They all work, the PSA was a $69 blem I gave it to my Son when he came home on leave.
He loved it, and it runs great.

The Joe Bobs is great quality and runs great.

Foxtrot Mikes was designed by a mechanical genus.
I have not shot it yet, but being a lefty I cant wait.

So yeah, NFA is really goood

I have two and they run great. I use them with the slick side upper on one and the side charger on the other.

Their BHO is a wire part that picks up on the Glock Mag follower and runs back towards the bolt catch.

I have not tried to run their parts mixed with others, so no opinion good or bad there, sorry.

We really like our NFA 9mm PCC so expect to have a hard time wiping the grin off your face when you finish yours.

I have an NFA billet Glock lower on my USPSA PCC ... over 7000 rounds with a PSA upper with MAS defense barrel without a problem... backup is a PSA (NFA made) lower, Aero Precision with PSA barrel with MI (PSA hand guards on both), which is an older short throat PSA barrel....it is my test bed and currently shoots 95 grain Precision Delta at about 1380fps very accurately with little scope movement... I believe the current PSA barrels are throated longer

They're nice lowers.

I use their side-charger for LRBHO, but it isn't necessary.

Using a 5.5" BA barrel and have shot a half dozen matches this year without a single malfunction.

Just a heads up.  The New Frontier Armory 9mm Glock lower is not like a mil-spec forged AR-15 Lower. If you install hand guard
that attached with screws that are installed from the rear and go through an indexed barrel nut (ex. the a UTG Pro 4.2 inch MTU008),
you will have to grind down the lower to make a path for the machine screws.

Other than that hiccup I like the New Frontier Armory Lower very much.
Notes:
1) the New Frontier Armory lower does not have the Hold Bolt Open feature, so you
need an Upper that does that job, ex. the New Frontier Armory upper.
2) A 5.5-inch 9mm barrel is shorter than an AR-15 5.5 barrel by the length of the extension, in that
the 9mm barrel has no extension, which means that the end of a 4.2-inch hand guard is just short of the start
of the muzzle threading on a 5.5-inch 9mm barrel.

I've experience with two billet NFA Glock 9mm mag lowers.  Both seem to be ever so slightly wider than mil spec.  On both the front (pivot) upper pin is tough to push out of the closed position; and I tried to install a ambidextrous selector on one, but it dragged (and scratched) on the right side of the lower.   Other than that, nothing to gripe about.  Mags (at least Glock - I don't have any non-factory mags) are angled correctly for reliable feed, drop free.  On one of the lowers I got the NFA side charge, LRBHO upper that only had to have the LRBHO rod bent a very tiny bit to get 100% function.  Makes a nice companion to a Glock 17/19/26 pistol.

Best of luck with whatever you decide to pursue.

MHO, YMMV, etc.

I’ve build 2 joe bob lowers now that are ar9mm. But both slick sided upper with side charge. The first one I sold but I missed it so I built another one.
This one I have now is a 4inch version and I love it. I love the compactness of it and especially when suppressed with my obsidian.

Pretty sure joe bob lowers are contract made by New frontier.

My lrbho is on the side charge upper. Works everytime no issues.

When I first looked into making an ar9mm I started going the ar15 lower with a Hahn magwell adapter (before ar9 glock style etc lowers flooded the market) I had built the lower and then for some reason wasn’t liking the colt setup so I sold it and got the glock setup. For some reason (for aesthetic purposes I guess) id love it if the magwell was able to hold a mag kind of like how a straight mag on an mp5 is or a ump45. Love that look.

Good info guys, thanks.

So, out of curiosity, if I really wanted to go overboard and build a direct impingement 10mm... I'd probably want a different lower so I could use a standard upper and keep the LRBHO function?

for the DI 10mm, I'd check with Rudy, the Mad Machinist at Macon Armory

You won't like it- no gas shield, and the CH is too big and on the wrong side.

Nope.

You can run it on any standard 9mm upper without LRBHO.

I had a 10.5" CL RRA on mine for a long time before I picked up the NFA LRBHO upper.

I'm still super happy with it, but tweaking the wire was a PITA... with NFA upper and lower it wasn't reaching the follower. I bent it (too much) and it locked 100% of the time with one round left in the mag, because it was reaching into the mag. I bent it again, and now it's perfect function with Glock pistol mags and Magpul 21's, but my Glock OEM G18 mags for some reason still actuate it with one round left.

I guess I need one more bend...