Ejection Path

[No Bananas]

I was tryng out my new AA piston conversion kit on my 10.5" SBR today. I put in an H Buffer. The rifle ejected the brass at a 2 - 3 O'clock postion about 4 to 6 feet away. This is about the same as my 12.5" SBR (Direct Impingement) w/ H Buffer. Never had any issues with function on that rifle either. Does this ejection path mean that the buffer is too heavy or is just right?

Most ARs I see at the range shoot brass 8 feet or so to the 5 O'clock position.

[m4fun]

If this follows normal piston rules - FAL like - more gas/hotter loads forces the ejection forward. Less gas/weak ammo and the ejection is to the rear. ideal is, and when you can tune the system, you want ejection perpendicular. Not knowing your piston gun but it being the same as your DI setup, if you do not have a gas regulator, try an H2.

[Robb Jensen]

Ejection pattern has much to do with extraction tension and bolt velocity.

[No Bananas]

Ejection pattern has much to do with extraction tension and bolt velocity.

So, is my bolt velocity OK by the pattern it has presented?

[ADC]

4 - 5 O'clock is perfect, I would try a H2 buffer in it, understand it depends on the ammo as well, what are you blasting with?

[Robb Jensen]

I agree with ADC piston ARs feel best to me with H2 buffers.

[No Bananas]

Interesting. I would think that a heavier buffer would make the bolt move more slowly, and thus eject more to the front 1 o'clock range. Intuitively, I would think that I'd want a lighter buffer if I wanted them to eject to the rear or more forcefully.

I tried all kinds of ammo. PMC Bronze 55 gr. fmj, PPU M193, Win. Q3131A1, Fiocchi 77 Gr. Match, Hornady TAP 75 gr., and ATI 62 gr. All shot and ejected.

I don't care where or how it ejects, in terms of preference or convenience. Only in terms of function. If the current ejection path does not indicate a possibility of a malfunction (in the future), I'm cool with it.

[Slippers]

Interesting. I would think that a heavier buffer would make the bolt move more slowly, and thus eject more to the front 1 o'clock range. Intuitively, I would think that I'd want a lighter buffer if I wanted them to eject to the rear or more forcefully.

It's actually the other way around, most of the time. Lighter buffers usually result in an ejection path towards the front while a heavier buffer ejects to the rear. It has to do with how the casing hits the deflector.

[curmudgeon9]

There's a code-red buffer spring and an 'H' buffer in my 14.5" M4; it deposits the ejected casings in a nice, neat little pile about 6' away at 2 o'clock. This is about perfect for my situation at the range because brass flying around to my side or rear would be hitting my fellow shooters. (Also makes it convenient to collect for reloading.) That brass deflector is an engineering marvel. lol.

[Quentin]

This ejection path graphic looks helpful: