AR-15 Ejection question

[maxxram]

Hello,
I was shooting my AR-15 yesterday and for the first 90rounds the shell casings would eject and land about 8' to the right. Then on the 4th mag half way through they shells started basically just landing on the rest next to the rifle. Also about every 5th round, I could feel a shell bouncing off the side of my hat.

What would cause this issue and what should I be looking at on the rifle?
I pulled the bolt while at the range and looked it over, but saw nothing out of the ordinary. Also tried 2 more mags and the problem remained.

Thanks for any advise you can give.

[cds_arms]

What brand is the gun? If it's a build, what brand is the bolt carrier group?

Shooting steel or brass ammo?

It's likely that the casing are sticking in the chamber just a little or the gun is experiencing hard extraction. Once the chamber heated up, if it was slightly undersized or the ammo was junky, it could cause that problem. It also could be a weak extractor spring possibly.

I'd say switch to some different ammo and try it again. Give it a go with a some more rounds and see how it works. Give the BCG a good cleaning and lube.

A combo of weak ammo, stiff buffer spring, too heavy of a buffer, tight chamber, bad extractor /spring, undersized gas port, or a combination of any of the above could cause that problem.

If it's a 16" or larger barrel gun it should run 100% even with cheap steel ammo. Some short SBR's are iffy due to reduced backpressure. I have an 11.5" piston SBR that still won't run 100% unless suppressed with cheap Tula. Still need to work on it a bit.

[maxxram]

Its a Bushmaster Co-witness flat top. I only shoot Brass cased ammo in it.
Currently its the American Eagle brand that i got at Cabela's.

Thanks for the advise so far. I will break down everything and see if i see anything and clean it up good.

Its just odd to me that it was working fine then all of a sudden started having issues. I did just clean and lube the bolt assembly the night before. Is it possible i put to much or to little lube on parts? I used this as a guide as to where to lube and how much.
http://www.weaponevolution.com/forum...15-LUBE-POINTS
I did not do anything with the buffer tube assembly. Only the Bolt assembly.
Thanks

[Hawk]

Is this a brand new rifle? Have you shot it before?

[maxxram]

Is this a brand new rifle? Have you shot it before?

I've had it for about 2yrs. I have shot it plenty of times before and never had an issue.

[Dakota 35-1]

Did you notice any difference in the recoil in conjunction with the change in ejection?

[maxxram]

I honestly did not notice any difference in the felt recoil. I don't know if it matters but during recoil you could hear the spring in the buffer tube make a "springy" sound. I know that's not exactly the best description but that's the only way i can think to explain it. It made the same sound while shooting the rounds that ejected fine though.

[redturbo0]

did you change your ammo half way through? Different brands can perform differently.

[maxxram]

There were no ammo changes

[redturbo0]

I honestly did not notice any difference in the felt recoil. I don't know if it matters but during recoil you could hear the spring in the buffer tube make a "springy" sound. I know that's not exactly the best description but that's the only way i can think to explain it. It made the same sound while shooting the rounds that ejected fine though.

this could have been your ejection problem, if you can, I would compare your spring to that of an ar you know that works flawlessly. Or try the flawless spring in your ar, and see if that works.