9mm AR Advice - how to feed 147 flat nose bullets...

[SMTGWKD]

I built a 9mm AR to use with an echo trigger lower using the following components:

Faxon 4.5" barrel
3-lug Adaptor
Either Griffin Revolution 9 or Octane 45
Faxon 9mm Bolt (had to shave down material to clear the auto sear trip mechanism of the echo)
Kaw Valley Precision 10 oz Buffer
Kaw Valley Precision Extra Power Spring
Aero Lower
Anderson Lightweight "slickside" upper
Kaw Valley Precision 7" Konza Rail
SB Tactical PDW Brace
Pro Mag Adapter (new version)
C-Products 32-round magazine

I test fired multiple brands of ammo from 115 grain to 147 grain and the only one that had issues was the 147 flat nose American Eagles (the ammo I have stockpiled the most of!) They would run well sometimes, then others they would angle high in the chamber and fail to feed. The exact same failure every time.

Do you think a different magazine would solve it?
should I do something with the follower?

It ran incredibly well with all other ammunition and controlled pairs were super accurate otherwise.

Thanks in advance!

 

[bfoosh006]

Try a Metalform Mag... the feed angle is not as severe as a C-Products follower. Brownells sells the best version of Metalform IMHO. They have a nice slick coating on them.

Also .... disassemble the C-Products and check for any burrs or something that might be causing the follower to drag.

Is the firearm well broken in ?.... you might consider polishing the edge where the feed cone meets the chamber ever so slightly , as in a a .20 Gauge bore mop spun by a drill covered with car polish on the tip.

 

[SMTGWKD]

Try a Metalform Mag... the feed angle is not as severe as a C-Products follower. Brownells sells the best version of Metalform IMHO. They have a nice slick coating on them.

Also .... disassemble the C-Products and check for any burrs or something that might be causing the follower to drag.

Is the firearm well broken in ?.... you might consider polishing the edge where the feed cone meets the chamber ever so slightly , as in a a .20 Gauge bore mop spun by a drill covered with car polish on the tip.

Great advice - I'll try the break in method first. I only have about 50 rounds total through it.

Have the Metalform Mags really solved this issue in the past? Thats great to know.

 

[2ndamendfan]

So i have had a similar issue with mine. Only it was/is hollow point ammo. Ball ammo not an issue for a couple thousand rounds. I love the gun and personally it is perfect defense gun. No recoil at all really. 32rds of 9mm should get the job done. Having shot 1000s of .223 at all kinds of barriers i fail to believe some bull shit that 5/8 dry wall will stop a 223 while i have seen it go through 2 4×4 posts clean as a whistle and most tests show 22inches of penetration in ballistics gel.

So with that. I got a great deal on some plated hollow point ammo and bought a few cases. This is not premium $19.99 for 20rd ammo. The ammo was for practice and I never really intended it for personal defense. I had about 2000 rds of 9mm FMJ through mine and not one single jam.

I felt i was go to go. Try cheap hollow points (price was right ) and instantly started having random jams. I then started trying every possible hollow point. With Sig being the worst. Very inconsistent jams with the cartridge standing up at about a 45 degree angle.

Now i fancy myself a hobbist gunsmith and I meticulously examined everything i could. And the obvious thing to me was that with FMJ the bullet was just inside the chamber when the brass was released from the mag lips. Just by like 1/64 of an inch, but it was in and guided into the chamber. But hollow point ammo (similar profile to flat nose) was about 1/32 from the chamber when the mag let go. So hollow points had to "jump" into the chamber unguided.

Another thing i noticed was that it never jamed on the first round. Either dropping the bolt from the bolt stop or inserting the mag and pulling the charging handle. So i knew it could work.

So i went to the local store and started looking at bullet profiles. Bought 3 boxes of every self defense 9mm ammo possible. Right of the bat the Barnes and Browning (uses Barnes bullets i believe) ammo were hugely better. Still a stopage on occasion. I would load a mag staggered with all different types of ammo. At fisrt the cheap hollow points and the Sig ammo was the worst.

After many many shooting sessions i noticed that things started to get noticeably better. At that/this point i can attribute every stoppage in the last 1000 rds of hollow points to being the last round in the mag and only with Mag-Pul mags.

I have 2 Mag-Pul mags, and with hollow points they will jam on the last round 100% of the time. I have one factory Glock 32 rd mag, 2 Korean knock offs and 3 ETS mags. Those mags have not had a single malfunction in the last 1000+ rds.

I put 200 rds of the cheap hollow points through it yesterday and not one single jam. Something "broke in" i am not sure if it was in the Mags or in the gun.

I will say that i am not sure i ever had a jam with the factory Glock mag. As at first i never used it. I really dont care for the way it "looks". Big old long thing hanging out like a horse's dick. It wasn't until i got the Korean 32rd mags that i started to use the factory mag. But by this time i had started to notice less and less jams with the Mag-Pul and ETS mags. So I started to keep track of mags and stoppages per mag. The Korean mags have been great, same as the factory. Noticed the Mag-Puls were the worst with a jam on the last round 100% of the time.

I will say this, as a defensive gun i keep the gun clean. Bolt, and inside reciever. But i am nervous to clean the feed ramp as that has some good carbon built up on it and the gun is working. Just saying.

I know long story but i learned a lot. If only those feed lips were about 1/32 inch longer.

My daughter has a AR-15 i converted to 9mm using a conversion block and colt mags and it has always eaten everything with out a hick up. The issue with that gun is lack of different size mags/mag choices and the mags are near impossible to load without a loading tool. But the gun itself is 100%

 

[2ndamendfan]

Great advice - I'll try the break in method first. I only have about 50 rounds total through it.

Have the Metalform Mags really solved this issue in the past? Thats great to know.

So less than 2 full mags. Yea there is some break involved. I can shoot less than 25 rds in a session don't get me wrong. But sure as hell not with something as fun as 9mm AR. And yes they are accurate. Hits on a 50% IPDA target at 125yards are very easy.

 

[MTRecon]

In response to the OPs question on changing magazines I would agree or would at least try breaking them in first.

I have a CMMG MK9T in 9mm and have ASC mags in 10, 20 and 32 round capacity. The 10 round mag needed breakin before it would function as did the one 32 it came with. I kept them fully charged when not in use and the function issues went away fairly quickly.

 

[Shifty6BR]

I had terrible feed issues at first with Metalform mags feeding plain ole 124gr round nose. I let all the mags sit overnite fully loaded to "season" the springs. Next day she ran like a top and has never hiccuped since some several thou round later. If this doesn't help you might want to look into having the feed cone addressed, there is a gentlemen at Macon Armory who specializes with this issue and guys who have used him absolutely rave about his work. Best of luck to ya!!