I've noticed that since I switched to a piston kit that my spent cases don't eject as far.  I don't know if this a good thing, symptom of a potential problem or what.  My cases will eject to about 2-2:30 three to four feet out.  On a few rounds I've seen the cases actually eject nearer the 1 o'clock area.  I'm going to be shooting more this w/e I'm going to watch it again.  The bolt has a lot of rounds and got pretty hot just prior to the kit switch out.  Maybe I need a new ejector spring.



M

I don't know much about piston kits, but could it be with the addition of the piston and therefore more mass, you are taking energy out of the force imparted to the bolt, therefore slowing it down and changing your resultant ejected case location?

How many rounds are on that bolt?  I don't know of many ejector springs that have failed, do you mean an extractor spring?

edit:  a little clarification:  the pressure imparted to the piston is the same or near the same as what would travel down the gas tube, I think.  (I'm assuming the gas port is about the same in either a DI or piston)  What I was getting at is that piston has mass and I suspect the bolt carrier has a little more mass than normal and those two masses have inertia and that inertia is what slows the bolt compared to a DI gun because you have to accelerate that mass.

I noticed with the CMMG that when the gas was leaking (system wasn't working as effectively), the cases ejected at the 4-5 o clock position (really soft felt recoil). When the gas system was fully operational, the cases were coming out at 1 o clock.

Thanks for that info.  I took the gun shooting Saturday and watched a buddy shoot it.  The more I think about it the more I think that as stated above the mass slowing the BCG down has changed it.  I think I will be ok.  



Thanks








 

Which piston kit ?

What type of buffer ?

What type of ammo ?

 

My piston drive SR556 tosses its brass across the border, on the factory standard setting (2). I can slow them down by throttling back on the gas port size. Just adjust your gas up for farther ejection if you want it,  but you want your gun running with the lightest setting that is 100% reliable anyway, and just crank it up if it gets really dirty or you use lower powered ammo.

TNRonin,

I'm not sure if you'll come back and check or see this or not, but I'll post it just in case anyways. When I installed the Adams Arms carbine piston system into my Stag Arms AR (lefty model though it makes no difference other then I couldn't use the right handed bolt carrier and had to use a stock left handed on and a carrier key), this is what I was told.

It should eject just fine. But, if it doesn't, and it ejects to softly you then need a lighter buffer. Thus then if it ejects to fast or hard, you'd then need a heavier buffer.

It might also be advisable to change out the buffer spring.

Also watch out for carrier tilt. If you notice some gouging or meta shavings at the mouth of the buffer tube, you may then also have a carrier tilt issue? I know, you said you have brass shavings. I was just adding this info for you in case you notice or noticed an issue at the buffer tube as well?

But back to the ejection issue, I was told it should eject anywhere from 1-4 O'clock. That it's how it ejects that can indicate something is or could be amiss and that you should pay attention to.

I was told this from other people that have converted their Ar to piston as well as I was told some of it from Adams Arms.

Glock, thanks for the thoughtful reply.  You may have me confused with someone else.  I've not had any cooper shaving issues.  I've checked the buffer tube and I have very little "buffing" of the leading edge so I don't think I have much carrier tilt if any at this point.  I know that my buffer spring is lighter than my son's AR so that is not an issue.  I've not had anything even close to a malfunction.  I suspect that this is just the nature of the piston system as it doesn't throw the carrier back as hard as the gas system, as I've seen it.



Mitch