Erratic Ejection Pattern

[the AR-15 Junkie]

Two things.

1. Overgassing won't cause head swipes, so no surprise there. and

2. Do you happen to have one of those God Damned Retarded Springco buffer springs? I tried one of those once and totally effed up a decent running carbine.

last possibility is there's a poorly button rifled barrel that's got tight or overbore spots.. and it just needs to be replaced. pin gauging the bore would tell you if that is possibly and issue.

Agreed, sprinco is all SOTAR hype.

[Jstud220]

I’m surprised to see the dislike for Sprinco extractor springs. I have one in all of my Bolts and have had nothing but great results from them.

[rifleman8]

Mid-length, .093, lots of bolt-over-base, ..........bolt bounce from hell ?

[curious1]

Might check and make sure the hammer in the lower can be pushed down as far as the carrier pushes it on cocking without binding between it and the trigger. Also would check that the hammer can push past the disconnector with the trigger pulled without binding. Odd but if there was binding on cocking it might slow or partial restrict the carrier's movement.

[JoeBobJoe]

Might check and make sure the hammer in the lower can be pushed down as far as the carrier pushes it on cocking without binding between it and the trigger. Also would check that the hammer can push past the disconnector with the trigger pulled without binding. Odd but if there was binding on cocking it might slow or partial restrict the carrier's movement.

I thought the same thing, that it might be the hammer or even a bent buffer tube slowing the BCG. But I swapped lowers with my friend's midlenth upper and my upper still acted funny & my lower ran her upper fine. My upper runs good on a rifle lower, 3:00 ejection 7 feet. It only ejects about 3 feet in a downward angle at 1:30 to 4:00 on a carbine lower with a 4oz or 3oz buffer, also a 3.8 oz buffer . I am gonna try a H3 or heavier buffer soon. But it seems reliable with the rifle length & weight buffer system. I can't understand why the ejection is so erratic & unreliable with the carbine lowers.

[sinister]

First, mid-length should have helped by dropping port pressure. You opened up the gas port and went to over-gassing.

If it works with a rifle lower and buffer you can try one of Clint's HSS or XH buffers. A T2 using tungsten powder, shot, or dust does not necessarily have the same dead-blow action as solid weights sliding back-and-forth.

Bottom line though, if it's feeding, cycling, ejecting empties overboard, and locking the bolt to the rear on an empty magazine WHO GIVES A FLYING RICARDO where the brass goes? Why is that important?!

If brass goes ANYWHERE from 12 to 3 the "Brass deflector hump" where a lefty doesn't constantly get hot empties in his kisser is doing its job.

[Kyohte]

From a practical perspect, that upper is toast. Having a barrel with a 0.93” gas port is going to induce further problems down the line. I would ditch the entire thing and save yourself further headache.

Chalk it up to experience, buy a BCM/Sionics/LMT, and if something goes wrong with it, send it back to the factory.


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[sinister]

From a practical perspect, that upper is toast. Having a barrel with a 0.93” gas port is going to induce further problems down the line. I would ditch the entire thing and save yourself further headache.

Chalk it up to experience ...

It sounds like it needs a new barrel at the least.

[FromMyColdDeadHand]

Out of the experiments, did you run another carbine buffer lower? You said it works on a rifle buffer tube lower, and you’ve tried different weight buffers on your carbine set-up, but I didn’t hear if you tried a different carbine set up lower. Just ‘filling out’ the matrix

[corey4]

try swapping receiver extensions on the lowers. it only takes a few minutes.