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View Full Version : Brass ejection ... How far...????


david.bergen
08-03-09, 09:30
I build a 11.5 inch upper with a carbine gas system,
Colt full bolt carier and a standard carbine buffer. The gasport size is 0.0787 (2 mm)
When compared with a hbar rifle the carbine ejects the brass much farther
(between 8-10 feet at 4 o'clock ). When I examine the brass there are no pulling marks from the extractor on the rim. Is this setup good to go or did I over gas the system? Any suggestions for correcting?
David
markm
08-03-09, 10:08
Sounds good to me.
Winn
08-04-09, 21:31
Not sure about the distance in particular (but would like to know more), however, my understanding is that the brass should be landing somewhere closer to between 1 and 3 o'clock ... rather than 4 o'clock.
lanceriley
08-04-09, 23:38
no pull marks on the brass should be good.
Darkop
08-06-09, 15:02
Not sure about the distance in particular (but would like to know more), however, my understanding is that the brass should be landing somewhere closer to between 1 and 3 o'clock ... rather than 4 o'clock.

All of my Colts eject 8-10 ft at 4 O'Clock. Your rifle is just fine!

Until that day,
Darkop
decodeddiesel
08-07-09, 10:05
Sounds like everything is OK, but you may want to try an H or even H2 buffer with that weapon. It may help slow things down a little (a good thing!) and reduce your recoil slightly. Just make sure the bolt will lock back on the last round with the heavier buffer.
Winn
08-07-09, 12:14
All of my Colts eject 8-10 ft at 4 O'Clock ...

Until that day,
Darkop


What barrel length, gas system and buffer do you have ?
Miale
08-07-09, 13:20
Not sure about the distance in particular (but would like to know more), however, my understanding is that the brass should be landing somewhere closer to between 1 and 3 o'clock ... rather than 4 o'clock.

anywhere from 3 to 5 o'clock is fine, in advance of 3 and your carrier is travelling too quickly indicating over gassing
Winn
08-07-09, 20:28
anywhere from 3 to 5 o'clock is fine, in advance of 3 and your carrier is travelling too quickly indicating over gassing


Not according to one of Armalite's Tech Notes.

Unless thay have revised their info, they have indicated that the most desirable ejection pattern for any AR type system is between 1 and 3 o'clock. And based on that, one could extrapolate that the 2 o'clock position is just about ideal ... rather than 4 o'clock.
goodoleboy
08-07-09, 20:44
Is the 8-10 feet from a standing or bench position? My Colt 6920 throws about 7 or 8 feet from a seated position around 3 o'clock. That is from a 16.1 inch barrel operating on a carbine length gas set-up (which is going to chuck them a little harder than a 14.5 and below).

I don't think that 8 -10 feet from between 3-5 o'clock is unacceptable. What type of ammo are you shooting?
87GN
08-07-09, 21:10
FWIW, we were messing with a 12.5 N4 earlier today.

It ran best with an H3 buffer and was ejecting around 3 o'clock.

With the carbine and H buffers it would eject around 1-2 o'clock but sometimes had bolt over base malfunctions.

And...regardless of buffer weight, my 16" 5.45 ejects at 4 o'clock.