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Colt
July 22, 2007, 19:22
Here's a problem that's been screwing with my gray matter for awhile now and I'm about at the end of my rope with this thing. Frequent searches have given me worlds of information, but unfortunately, not the fix I need....


My DSA Stainless 16" every now and again fails to eject. I thought I had it fixed with a new extractor and extractor spring, but it happened again today. It happens so infrequently that I've thought it's been fixed more than once....and it reared it's ugly head again at the range today.

Once or twice per 100 rounds fired, it fails to eject. Sometimes, it's at the beginning of a range session, sometimes it's toward the end, but I can rely on it happening within 100 rounds--today was in the middle of the second mag. 2 failures to eject after about 30 rounds fired....the remaining 68 ejected normally.



Symptoms and observations:

The spent case is always out of the chamber and riding on top of the next round. Sometimes, it gets crushed in-line with the bore, and sometimes it's stovepiped out the ejection port and holding the bolt open.

I didn't take any pics, but there is a horizontal crease exactly halfway down every single ejected case (as in, EVERY case, not just the ones that fail to eject)....from the beating it's taking, and the fact that I have brass kisses all over my lower receiver, I assume they're hitting my dust cover on the way out....but when they fly out, they fly out with authority and land about 8 feet away to my 2:00.

Gas setting seems to be good--but I'm thinking it may be overgassed a bit. It never fails to lock the bolt open on an empty mag, and no pulled rims or excessive recoil.

The recoil springs and piston spring are new, and both recoil and piston tubes are clean--I thought the rust I found inside the gas tube was a probable cause, but it happened again after replacing it.

There is no binding on the bolt carrier (with or without the extractor installed), and no binding on the recoil plug. With the upper/lower apart, tilting the rifle to 45 degrees allows gravity to take the bolt carrier to full battery and it slides like it's on bearings. Likewise, there is no binding of the piston. I can drop it through the tube, and it goes all the way through the receiver. (the piston head gets a little tight 3" or so into the tube, but holding the rifle vertical will drop it straight through) I checked the piston for straightness on a glass tabletop--no issues there either.

It's always been clean and lubed when this happens, and it happens with Cavim, Port and SA surplus--several different lots of each. All of these have cycled/fed/ejected fine in my DPMS 308 and my Springfield SAR-8....as in 2K rounds without failures between the 2 rifles...the DSA is the only one that chokes.


If it was happening more often than once or twice per 100 rounds, it would be easier to troubleshoot and I wouldn't be bothering y'all with my questions....but what do I need to look at now?

SIG552
July 23, 2007, 01:53
+1. Ggggiillliieeeee has a reference to his ejector advice somewhere on this site and it seems to be a rather clearcut description of how the FAL ejector should be. Someone will be along soon with that link me hopes


SIG552

chromestarhustler
July 23, 2007, 03:01
extractor spring.

SIG552
July 23, 2007, 03:49
Originally posted by chromestarhustler
extractor spring.

He already replaced that

evan price
July 23, 2007, 04:06
Find ggiillee's ejector face modification advice, search on here for it. I had a similar problem with a kit build where the brass was ejecting too forcefully rearward, and getting too much spin on it, and was actually bouncing off of the rear of the ejection port and back into the bolt as it cycled.
Also try turning down your gas settings until it finally won't eject properly, then turn it up two or three clicks and see what happens on a more bare-minimum gas setting.

SIG552
July 23, 2007, 05:04
gggiilllliiieeeee's advice on the ejector mod can also be found on Wikipaedia. Just do a search on "FN FAL" and scroll to the bottom.

SIG552

Colt
July 23, 2007, 07:42
thanks for the insight fellas. I checked the ejector--it's tight and no defects that I can see. I started to do the ejector face profile....it's already been done. (gotta love buying used FALs!)

I gave it a coloring with a Sharpie and manually ejected 5 empty cases. The bright spot is pretty much exactly the desired result that was described in gggiggglee's tutorial.

when manually ejecting (yanking the handle as hard and fast as I can) an empty case gets thrown forward and down. As far as I can tell, it doesn't hit the dust cover or receiver at all. This tells me that the bolt is moving WAAAAYYYYY faster and harder than I can make it happen.

As suggested, I'm going to open the gas knob a few clicks and see how it performs with minimal gas....I'll be PISSED at myself if that's all this has been all this time.

W.E.G.
July 23, 2007, 08:57
I think you mean you will open the gas KNOB a bit.

If you open the gas PORT, you will only make a too-much-gas problem worse.

Mosin Guy
July 23, 2007, 09:37
http://www.falfiles.com/forums/showthread.php?s=&postid=1915851#post1915851

SIG552
July 23, 2007, 10:11
Gary,
I think he meant opening the "exhaust port" which the knob restricts and through which the gas escapes the rifle, as he is referring to how it will perform on minimal gas.

SIG552

Colt
July 23, 2007, 11:23
Originally posted by W.E.G.
I think you mean you will open the gas KNOB a bit.

If you open the gas PORT, you will only make a too-much-gas problem worse.




correct.....sorry



:p

ce
July 23, 2007, 12:04
Let's call it a "gas regulator", shall we, since that is what it does.

A knob is something that you yank on with a monkey fist.

And check the top of the ejector to see if it hasn't been modified like the face.
If it has been relieved too much, it may occasionally skiip under a round and leave the brass in the chamber.

I don't think the brass is bouncing back in once it's been out of the breech.

Colt
July 23, 2007, 12:46
Originally posted by ce
Let's call it a "gas regulator", shall we, since that is what it does.

A knob is something that you yank on with a monkey fist.

And check the top of the ejector to see if it hasn't been modified like the face.
If it has been relieved too much, it may occasionally skiip under a round and leave the brass in the chamber.

I don't think the brass is bouncing back in once it's been out of the breech.


well, the ejector doesn't appear to have been molested on top. It's still got nice, sharp 90 degree angles and finish on it. The spot that gets hit (according to the Sharpie) is about 1/3 from the top and slightly to the right of center.


http://i172.photobucket.com/albums/w19/Colt45guy/DSAejector002.jpg

http://i172.photobucket.com/albums/w19/Colt45guy/DSAejector001.jpg

and here's a shot of where it's hitting my dust cover...I'm not too concerned about the brass kisses, but it looks like a rasp has been drawn across the middle of the ejection port, and I think it might be a klew

http://i172.photobucket.com/albums/w19/Colt45guy/DSAejector003.jpg




eta: for the record, my rifle really doesn't stay this dirty.....I used a moly-b based spray-on grease and haven't cleaned it yet.