Failures to Extract


PDA






peck1234
October 9, 2008, 06:21 PM
Just got back from the range.... My AR-15 had 2 failures to extract out of 350 rounds... figure it just needs a good cleaning....

But as far as cleaning goes..... What else causes a failure to extract? My barrel was quite hot when both failures occurred, could this be possible....

Thanks Mike...

5.56 chambered... shooting .223... wolf poly

Just got the cartridge out.... stuck inside barrel wall with some gunk....

don't say its wolf!

If you enjoyed reading about "Failures to Extract" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
ATAShooter
October 9, 2008, 06:24 PM
Ammo info needed also... 5.56 or .223 ... Commercial store bought, Reloads, or surplus. Also, what is the ar that you have chambered for, .223 or 5.56 Nato?

briansmithwins
October 9, 2008, 06:30 PM
What length gas system? Chromed chamber? When did you last clean the chamber with a chamber brush?

I've used these to cure extraction problems in carbines before. I use them in all the ARs, rifle length and mid-length too. BSW

http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm

Larry E
October 9, 2008, 08:12 PM
If it's Wolf that's got painted cases instead of the stuff with poly coating it could be the Wolf. CLEAN THE CHAMBER!

anthony-white
October 9, 2008, 09:04 PM
Was the rifle clean before it went to the range? Possibly some junk in the chamber (i.e. shipping preservative in new rifles) that with said heat became like glue. I've had great luck with the poly wolf and wouldn't think it to be the issue. Either way, be on the safe side and take a look at your extractor and spring for problems.

peck1234
October 9, 2008, 09:13 PM
you said it anthony........thanks.... cleaned it all out today..... nice and shiny, chamber was filled with gunk...

Dienekes
October 10, 2008, 01:14 AM
Another thing to consider down the line is an extractor beef-up. Carbines are the usual culprits in this due to their more violent unlocking, but the fix for this is a dedicated O-ring or "D-fender" insert around the extractor spring. That produces about 3X the usual grip on the case rim. Had a couple of failures to extract with resultant double feeds on my carbine. Installed a D-fender and that took care of that issue.

Don't own a 20" AR but I think I'd put one in on principle. Can't see where it would hurt, and it probably would help matters anyway.

peck1234
October 10, 2008, 01:17 AM
interesting... thanks

but does it really apply shooting semi-auto?

http://www.fulton-armory.com/D-Fender.htm

briansmithwins
October 10, 2008, 01:28 AM
Yes the o-ring helps semi-autos that have extraction problems. A $0.20 viton o-ring from ace provides exactly the same benefit as the $10 d-fender. If you want to spend $10 get 2 of the BCM extractor upgrade kits. BSW

Funderb
October 10, 2008, 01:29 AM
That produces about 3X the usual grip on the case rim. Had a couple of failures to extract with resultant double feeds on my carbine. Installed a D-fender and that took care of that issue.


that sounds like a good way to destroy the extractor instead of the case.
I would only use one if one is needed due to poor extractor spring tension, not to amp up tension.

Some parts were meant to let go first in order to avoid more catastrophic failures down the line.

tantrix
October 10, 2008, 01:35 AM
What length gas system? Chromed chamber? When did you last clean the chamber with a chamber brush?

I've used these to cure extraction problems in carbines before. I use them in all the ARs, rifle length and mid-length too. BSW

http://www.bravocompanyusa.com/BCM-Extractor-Spring-Uprade-Kit-p/bcm%20extractor%20spring%20upgrade.htm

+1

The BCM extractor upgrade is great...I every AR I own has that kit installed. This is the the way I test an AR extractor: If you can squeeze the extractor & bolt together with your fingers alone and insert the extractor pin, there's not enough tension. With the BCM kit, the spring/Crane O-Ring is so strong you can't even install the pin back into the extractor without squeezing the extractor & bolt together with some pliers. I just use channel-lock pliers with leather covering the jaws so I don't scratch/damage the bolt. Squeeze the two together until the holes line up, and insert the pin. After a few rounds are fired, the spring and O-Ring will set and you will be good to go.

MartinS
October 10, 2008, 01:49 AM
I've had extraction problems with Wolf 223 in a Savage bolt gun, first shot, cold barrel. The case coating gets blamed a lot but the Wolf 7.62 and 5.45 we feed our AK's are just as coated, the chamber stays hotter and we get zero malfunctions. It is my understanding that steel and brass just don't behave the same way after the chamber pressure falls, the springback is different.
Chamber dimensions, case taper and all those other things that someone here smarter than me can handle.
I really liked the idea of the cheapest ammo in that Savage.

marsche
October 10, 2008, 05:18 PM
peck1234 asked "But as far as cleaning goes..... What else causes a failure to extract?" ....................................Over pressure loads can cause failure to extract. If the load is over pressure the extractor can rip the rim off the case and leave the shell in the chamber. As I always say - learn by doing :cuss:

1911Gunslinger
October 12, 2008, 04:54 PM
Steel cased ammo jams most AR's, they were not designed to use it, the chambers are tighter and their extractor only gets a small bite on the rim as well as having a weak extractor spring. Try installing an M4 carbine extractor spring available from Wolff it will increase the amount of tension and provide better extraction, the D fender works too but can go bad quickly depending on your shooting and cleaning habits.

peck1234
October 12, 2008, 05:37 PM
why would the extractor have a weak bite? the bullet is Identical?

As far as my problem went, my chamber just needed a good cleaning, cases were getting glued to barrel/chamber...

1911Gunslinger
November 2, 2008, 12:27 AM
The extractor spring on a AR rifle is not very strong but it works ok with brass cased ammo and chrome lined chambers. The steel cased ammo has a clear finish sprayed on it to keep it from rusting, sort of like the clearcoat on a car. Apon firing the heat generated causes the finish to become soft and sticky and it doesn't come out of the chamber as easily a a brass case. The result is that the extractor loses its bite and fails to extract. The clear finish will also build up in the chamber. When Colt developed the M4 carbine they found out that because of the fact they had to tap the gas closer to the chamber the gas pressure increased form 13,000 psi to 26,000 psi, the result was more violent extraction that occured earlier than on A2 rifles, because of the earlier and more violent extraction the barrel had more residual pressure in it and case had not had as much time to cool off and separate from the chamber, hence failure to extract. The solution was to use a stronger spring and stiffer black rubber insert which solves the problem.The increased extractor pressure keeps it from pulling off the rim of the case as easily.

Big Daddy Grim
November 2, 2008, 12:31 AM
Wolf ammo all wadger had the same problem with mine good brushing and your set.

RP88
November 2, 2008, 01:23 AM
Wolf is very dirty ammo. You put about 300+ rounds through any AR in a session and the gunk-up on even a chrome-lined rifle is enough to start causing FTEs, in my experience.

I put 240 rounds a couple weeks ago through my Del-Ton midlength. The last 40 rounds were brass PMC. After only having one FTE on the Wolf toward the end of using it, I ran the brass through, and had four FTEs from it - in a row.

Definitely gonna blame the gunky Wolf ammo here. After awhile there is simply too much dirt to make it run properly.

janobles14
November 2, 2008, 01:26 AM
its the heat and the ammo. bottom line. read the army field manual. they talk about live rounds sticking with heat (YES i know its full auto). but with these two factors i would put money on it.

If you enjoyed reading about "Failures to Extract" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!