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-   -   Carbine ejection question (http://forums.thecmp.org/showthread.php?t=218945)

slimedog 11-13-2017 04:13 PM

Carbine ejection question
 
Hi friends,

A couple years ago, I picked up a Blue Sky Imports carbine. The rifle, (Inland) was in kind of rough shape (but had all GI parts) and had ejection issues (FTE, double feeds, stovepipes). I stopped shooting it after an empty case was actually driven and stuck into the handguard.

So, I finally sent it off the CMP Custom Shop for inspection, a new barrel and reparking. I also put a walnut CMP stock on it. While I will post a full review with pictures, let just me say that it came back looking GREAT. The Custom Shop mentioned that the ejector spring was out of spec and replaced it. I ran 100 rounds of American Eagle 110g FMJ through it this weekend with no hangups.

The only issue was erratic ejection. My ARs and Garands tend to put brass into neat, little piles 6 feet away at around 3 and 2 o'clock, respectively. The carbine puts brass randomly between 12 and 6 o'clock, occasionally hitting me in the head. Sometimes ejected with authority, sometimes barely squirted out onto the bench a few inches from the rifle. While every case did make it out, I wonder if I have a geometry or spring issue.

So, experienced carbine users - should I expect consistent ejection or is this normal and acceptable behavior? Thanks!

HB of CJ 11-13-2017 05:34 PM

Easy To Tune ...
 
We must understand that normally the fired cases usually hit and bounce off the slide in ordinary conditions? This results in strange ejection patterns with the USGI Carbine?

What you can do is polish the bottom half of the bolt face rim. Also make sure the ejector is slightly below the bolt rim. Also make sure the ejector bottoms below the bolt FACE.

Both sides of the extractor can also be polished. Just try not to remove any material. Only polish. Finally both feed ramps can also be polished. Same thing. Do not remove.

What is attempted to be accomplished is creating conditions where the chaotic ejection somewhat becomes less so. To the point where the brass kinda goes the same place.

We tend to use factory Sellier and Bellot (horribly misspelled?) and Prvi Partizan, (sp?) ammo. Ejection can be best described as erratically predictable. Generally one pile.

6 Ring 11-13-2017 05:38 PM

Carbine brass can go anywhere. The type of slide also changes things. The type 5 slide mostly keeps the hot cases from bouncing off your forehead or going down your collar.
I agree, "one pile" from six feet in front to six feet back.

meplat 11-13-2017 05:51 PM

Quote:

Originally Posted by slimedog
The only issue was erratic ejection. My ARs and Garands tend to put brass into neat, little piles 6 feet away at around 3 and 2 o'clock, respectively. The carbine puts brass randomly between 12 and 6 o'clock, occasionally hitting me in the head. Sometimes ejected with authority, sometimes barely squirted out onto the bench a few inches from the rifle. While every case did make it out, I wonder if I have a geometry or spring issue.

So, experienced carbine users - should I expect consistent ejection or is this normal and acceptable behavior? Thanks!

My shooter puts them all pretty consistent out at 2PM, distance wise anywhere from 3' to almost 20'!

Your problem could be due to any number of things.

Are you using a late slide or early? The shape of the cam was changed so that riccochet (direction) of the spent case once extracted was more, err, consistent. Same with ejectors. If you aren't using the latest type, forget about ejection consistency.

Could be your carbine may also need a good cleaning. No telling how many rounds the good folks at the CMP needed to test your rifle. Most ammo tends to be pretty sooty.

:D

DaveHH 11-13-2017 10:58 PM

There are three shapes of ejectors each sends brass in a different direction. You might try one of each, they are cheap and are not marked to a maker like the extractor. Greasing the rails, the slide slot in the receiver side and the slots in the barrel will change the ejection spots. I use grease on mine.

slimedog 11-14-2017 04:24 PM

The rifle came back clean and well-lubricated from CMP. I will do some research on the actual parts tonight and post the results soon.

Thanks for the replies!

HB of CJ 11-20-2017 02:22 PM

Ejector Patttern Fun Study? ...
 
Has anybody taken the time and fun to try all the different USGI ejectors and see where that pile of brass ends up? Be a fun project exercising our profound ability to not correctly use that USGI bolt tool.

Don't forget that necessary transparent containment plastic bag. A dry cleaning bag works. Amazing hang times with dinky parts. Lost in the carpet forever. But ... sometimes the cat or dog finds the stuff. :)

Edit: How come we can't correct the title speeeling?

ACampComLegacy 11-26-2017 09:54 AM

Is it possible that even if it locks into battery, that the bolt lugs, or the bolt lug channels in the receiver are worn, and the bolt upon ejection is at different degrees of rotation each time???

ACampComLegacy 01-24-2018 01:24 PM

That's a 'yes', I'm guessing???

Quote:

Originally Posted by ACampComLegacy (Post 1657923)
Is it possible that even if it locks into battery, that the bolt lugs, or the bolt lug channels in the receiver are worn, and the bolt upon ejection is at different degrees of rotation each time???


meplat 01-24-2018 03:03 PM

I think speed of recoil, spring stiffness, and shape of both ejector and slide are all far more significant factors in brass placement than any fraction of a degree difference in bolt face / ejector orientation at the moment the spent case lifts free from the chamber and goes airborne. That being said, the brass ejection is a very "chaotic" system and I don't believe Ordnance Dept ever fully "resolved" the carbine's ejection "issues". It is what it is. While I've tried over the years to refine mine, I ALWAYS get the occassional "over the shoulder" case. Other than that, it's not "simple physics", it's actually "unpredictable"

:D


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