AR 9mm FTE

[erics79]

I just built a 9mm AR pistol. I'm having FTE in every magazine. Looking online I've found people recommending adjusting the ejector so it's up against the bolt carrier (up and to the left if you're looking at the bolt face).. Tried that with no greater success. The spent casings get turned to the right then are pushed forward along with the live round. I also noticed that the spent casings, when they are ejected, don't go very far at all. I don't know if that is typical in this caliber?

Any other ideas?

Below is what I am working with:
Spinta 9mm bcg
KAK mag adapter
KAK 5.5 oz 9mm buffer
Plain ol' Carbine buffer spring

[imashooter2]

If you're using factory ammo, I'd go with too much buffer or spring.

[Emptymag]

I was told that I should expect to see ejected brass land about 15 feet away - and that's exactly where mine lands - I measured.
Aluminum case stuff only goes about 5 feet though.

if arjohnson happens to see this, he may have some suggestions as he mentioned a few things to look at if I had any issues with my recent build.
Fortunately mine ran just fine so I didn't need to tweak anything.

I used a standard buffer tube and spring that were part of a kit - Anderson I believe.
I just replaced the carbine buffer with a RRA 9mm buffer although I'm unsure what the buffer weighs
I also have a Spikes Buffer Spacer.

[titleiiredneck]

Is your bolt ramped? If not are you using a 9mm hammer?

Is your mag block adjusted correctly and if the bottom loading one is it tight?

What mags are you using? The cheap plastic ones are crap.

You say carbine spring on your pistol, is it a carbine tube?

What ammo? If all the same type try buying a box of 124 gr or 147 gr as it has more inertia.

[homedefender]

If you're using factory ammo, I'd go with too much buffer or spring.

i highly doubt you have to much spring or buffer in fact it may be the opposite. i use a wolf extra spring and one of heavy buffers 12 oz buffers on my 7" barrel

[imashooter2]

i highly doubt you have to much spring or buffer in fact it may be the opposite. i use a wolf extra spring and one of heavy buffers 12 oz buffers on my 7" barrel

Increased buffer weight or spring rate will retard bolt movement. How will that aid ejection?

[Gunsnwater]

Well if it's too fast the case is caught by the bolt returning. It has to come back hard enough to kick the brass out, but return after it clears. I really want a high speed camera.

[Nate7667]

Have you tried loading a single round and firing both with out a mag and with a mag?
You may be dragging on the mag and or the next round loosing bolt speed.

GnW, I'm with ya....high speed recordings of every single thing I own

[homedefender]

Well if it's too fast the case is caught by the bolt returning. It has to come back hard enough to kick the brass out, but return after it clears. I really want a high speed camera.

^^^^ correct if the bolt is moving to fast weird stuff can happen. i have yet to see anyone recommend a lighter buffer in a ar9 due to the mechanics of a blowback.