Ejection angle?

[MistWolf]

...is it something like a weak extractor spring allows the claw to slip off the fired case sooner after extraction, thus ejecting it sooner into the bolt's cycle, and the case goes forward as a result?

Very close. What happens is that with a weak extractor spring, the extractor does not hold the case against the bolt face and as a result, the case does not compress the ejector spring completely. Therefore, ejection is weak and slower. Case rotation during ejection is slower. All of this adds up to the case bouncing off the deflector forward instead of to the side.

It's even possible for the empty to eject in such a way that it bounces back into the action facing backwards.

[Circle_10]

Very close. What happens is that with a weak extractor spring, the extractor does not hold the case against the bolt face and as a result, the case does not compress the ejector spring completely. Therefore, ejection is weak and slower. Case rotation during ejection is slower. All of this adds up to the case bouncing off the deflector forward instead of to the side.

It's even possible for the empty to eject in such a way that it bounces back into the action facing backwards.

Cool thanks for the explanation. I think I'm going to start compiling a list of things like this, just stuff to watch out for, in the "notes" section of one of my armorer or technical manuals, just so I have the information on hand in the event it comes up.

Is there any tricks to "test" for wear on extractors and ejectors and their springs before they fail? Basically a preventative maintenance check along the lines of a standing a BCG upright on the bolt to check the gas rings.

[markm]

Is there any tricks to "test" for wear on extractors and ejectors and their springs before they fail? Basically a preventative maintenance check along the lines of a standing a BCG upright on the bolt to check the gas rings.

You can rock an empty case into your newer bolts to develop a feel for the amount of ejector spring tension. However, in 20 plus years with the AR, I've never had to address that part. A bolt will likely be rotated out of action before that's replaced.

[ABNAK]

I would imagine that the lack of a brass deflector (if it doesn't have one, like a slickside or A1 upper) would skew the equation quite a bit as far as ejection patterns are concerned.

[Circle_10]

You can rock an empty case into your newer bolts to develop a feel for the amount of ejector spring tension. However, in 20 plus years with the AR, I've never had to address that part. A bolt will likely be rotated out of action before that's replaced.

Good tip, thanks!

I would imagine that the lack of a brass deflector (if it doesn't have one, like a slickside or A1 upper) would skew the equation quite a bit as far as ejection patterns are concerned.

I imagine it could. My guess is that the "equations" presume the presence of brass deflectors, just because by the time things like ejection angles became subject to scrutiny brass deflectors had become the standard.
I have guns with slickside and A1 uppers as well. My A1 rifle tends to eject around 4 o'clock from what I recall last I paid attention. And my slickside carbine was launching M193 brass forward until I stuck an H2 in it, which changed the angle to about 3 o'clock. I was getting occasional failures to lock back with it before switching to the H2, so the failures to lock seem to have actually been caused by *over*gassing in that case.

[SA80Dan]

You can rock an empty case into your newer bolts to develop a feel for the amount of ejector spring tension. However, in 20 plus years with the AR, I've never had to address that part. A bolt will likely be rotated out of action before that's replaced.

On my first AR (horribly overgassed M&P15), my ejector spring got battered so much it broke in 3 places. I noticed something was wrong when the ejection pattern switch to nearly 12 o'clock, but weak with it. It was easy to push down on the ejector with my little finger - I then had to dig the spring remnants out with a pin.

Replaced it with a sprinco part and it's been fine ever since (although since I took to building my own rifles years ago, I rarely shoot that one anymore as even with heavy buffer and spring, it's still a lot snappier than it should be). When I get round to it, I'll ditch that barrel and replace it with a better one.

[markm]

On my first AR (horribly overgassed M&P15), my ejector spring got battered so much it broke in 3 places. I noticed something was wrong when the ejection pattern switch to nearly 12 o'clock, but weak with it. It was easy to push down on the ejector with my little finger - I then had to dig the spring remnants out with a pin.

Replaced it with a sprinco part and it's been fine ever since (although since I took to building my own rifles years ago, I rarely shoot that one anymore as even with heavy buffer and spring, it's still a lot snappier than it should be). When I get round to it, I'll ditch that barrel and replace it with a better one.

An adjustable block or insertable port would help... They've got those gas tubes now too.

[SA80Dan]

An adjustable block or insertable port would help... They've got those gas tubes now too.

Good points - but I reckon I'll end up swapping it out for a midlength if I stick with 16".

[Circle_10]

An adjustable block or insertable port would help... They've got those gas tubes now too.

Gas blocks/FSBs are one of the only things on my ARs I don't dare screw around with, so those BRT gas tubes are something I intend to keep in mind as an option if I run into overgassing situations.

[Falshooter]

500 rounds and it's been 100% tells me not to worry.

Too many people are anal about ejection patterns IMO. If it functions fine that's all the proof I need.

If anything I would prefer to have a rifle a little over gassed than under gassed. That means it's more likely to work in sub-freezing temperatures or when dirty.

I'm really happy with any rifle that ejects brass between 2:00 o'clock and 4:00 o'clock. I don't lose any sleep if a rifle goes outside this range so long as it keeps running.