Adjustable gas block and brass ejection distance

[Jmccracken1214]

Does the gas on a ar have anything to do with how far the rifle is throwing the spent cases?
My 6.5CM ejects perfectly to 4’oclock, with the majority of cases landing in a pile, but the concern is that they are landing like 8 feet away.
Will turning the gas block down slightly have them eject properly but not thrown as far? They usually land almost 2 bench’s down from me at the range.

 

[roostercogburn98]

Is the brass damaged in any way after ejection? How is your recoil impulse? A hard/fast moving bolt can make brass fly far. If you have an adjustable GB, turn it down a notch or two and see if that helps. You might have to tune the buffer/spring combo to slow the bolt down though

 

[larryh128]

Everyone has their own way of tuning gas but I turn down the gas until the bolt fails to lock back on the mag. Load 1 in the mag and fire. Then open up about 1/2 turn if you are using a screw type or 1 notch on other types. 10's typically chuck them a good distance.

 

[hlee]

Set up a brass catcher on your bench. If the rifle is functioning well, don’t sacrifice reliability for ease of brass collection.

 

[bfoosh006]

Don't forget to factor in your ejector springs strength.

And as mentioned, proper Adj. GB settings can make a difference... but I am in the same camp reliability wise.

 

[supercorndogs]

Yes, the gas does but its not the only factor. My 6,5 Grendal ejected the brass pretty far for an Ar-15 at one point during tuning. It also exhibited a symptom where it would tie three shots in a not, and two shots would always turn the group close 1.5 MOA. I was running an H3 buffer and Wolf extra power spring. I changed back to a standard carbine spring, and turned the gas way down. Ejection isn't as far, and accuracy is way better. Now the other two shots join the party.

 

[r.tenorio671]

Does the gas on a ar have anything to do with how far the rifle is throwing the spent cases?
My 6.5CM ejects perfectly to 4’oclock, with the majority of cases landing in a pile, but the concern is that they are landing like 8 feet away.
Will turning the gas block down slightly have them eject properly but not thrown as far? They usually land almost 2 bench’s down from me at the range.

...a 4 o'clock pattern is pretty darn good, some might even say "optimal". The distance the ejected casing travels is influenced by the type of surface it's landing on (concrete, gravel, dirt, etc.) as well as the strength of the ejector spring in use. The reliability of functioning is more important than where the brass ends up at. Consider that if you had to use that platform in a critical situation you wouldn't (or shouldn't) be concerned about where the brass is going. If you want, you can adjust your gas block but with a 4 o'clock pattern already, depending your type/brand of ABG, you may already be close to or at the borderline of achieving "reliable functioning" for the granularity of adjustment for that AGB.