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View Full Version : 308 extractor lip broke after 600 rounds **pics of extractor**


triggs75
04-10-2012, 7:38 AM
Well after a few hundred rounds the lip of my extractor broke off leaving a fired casing in the camber. No biggy just pushed it out. After a little google it seems to be pretty common.

I ordered another one and will contact DPMS to get a replacement. My question is, is there a upgradeable part such as a hardend/stronger one you guys know of?


Thanks

Chad

ott1
04-10-2012, 11:27 AM
Were you shooting milsurp or commercial ammo?

triggs75
04-10-2012, 11:59 AM
American eagle 155 gr. brass rounds

triggs75
04-13-2012, 7:26 PM
Ok so I just ordered a spare DPMS extractor from midway for now and will contact DPMS directly to see about getting a replacement for the broken one.

You can see were it broke the lip right off of the extractor.

http://img836.imageshack.us/img836/1926/img1847h.jpg

http://img838.imageshack.us/img838/1041/img1849n.jpg

Chad

SR-71 BLACKBIRD
04-13-2012, 7:42 PM
Wow, that's a trip. I wonder why that happened? Keep us posted.

ott1
04-13-2012, 10:03 PM
Does it old extractor spring looks stiffer than the new one? The spring on the broken extractor looks to be compressed more and slightly beefier.

triggs75
04-13-2012, 10:14 PM
Wow, that's a trip. I wonder why that happened? Keep us posted.

That's what I said. :43:

Does it old extractor spring looks stiffer than the new one? The spring on the broken extractor looks to be compressed more and slightly beefier.

The old spring is not beefier but it is more compressed.


My thought is the .308 is just one powerful bad a** round for the extractor. :cool2: That's why I was seeing if there is an enhanced one.

SR-71 BLACKBIRD
04-13-2012, 10:21 PM
My thought is the .308 is just one powerful bad a** round for the extractor. :cool2:


Nice........, LOL. That's the same way I feel about my AR308.

thrillhouse700
04-14-2012, 10:36 AM
I got this one, 2nd row from the bottom all the way to the right, it fixed all my extraction issues and looks awesome. http://www.pof-usa.com/parts/308parts.htm

FeuerFrei
04-14-2012, 11:52 AM
OP
did your rifle display any signs of being overgassed before the broken extractor?
curiosity on my part.

gemini1
04-14-2012, 12:42 PM
Wow! is this issue normal with 308 ARs or is it just with DPMS lpks?

russ69
04-14-2012, 12:51 PM
A stress riser could have been inherent in the part. This is a good candidate for shot peening to reduce the possibility of risers causing failures.

triggs75
04-14-2012, 6:47 PM
I got this one, 2nd row from the bottom all the way to the right, it fixed all my extraction issues and looks awesome. http://www.pof-usa.com/parts/308parts.htm

Thanks for the link, I will give that one a shot.

OP
did your rifle display any signs of being overgassed before the broken extractor? curiosity on my part.

Not to my knowledge, it runs just fine with no FTE's. I do have the Heavy CAR10 buffer in my rifle that could be slowing it down if it is overgassed.

Wow! is this issue normal with 308 ARs or is it just with DPMS lpks?

Not really sure, but when I was searching Google on dpms 308 extractors, this is definitely not the first one.

A stress riser could have been inherent in the part. This is a good candidate for shot peening to reduce the possibility of risers causing failures.

That would be nice.

FeuerFrei
04-15-2012, 12:13 PM
OP
the reason i ask is that my 16" upper was blowing primers once in a while with wolf and surplus ammo. over gassed will play hell on extractors. even on 556 rifles.
no FTF or FTE on any ammo used.
the action was very dirty (more than it should be) plus brass shavings.
scratched bases of fired ammo as well as throwing empties a country mile.
while i installed a troy rail on it i took the opportunity to swap out the gas block with an adjustable to dial down the pressure.
all is well and things run smoother and still cycles reliably. easy fix.

triggs75
04-16-2012, 8:56 AM
OP
the reason i ask is that my 16" upper was blowing primers once in a while with wolf and surplus ammo. over gassed will play hell on extractors. even on 556 rifles.
no FTF or FTE on any ammo used.
the action was very dirty (more than it should be) plus brass shavings.
scratched bases of fired ammo as well as throwing empties a country mile.
while i installed a troy rail on it i took the opportunity to swap out the gas block with an adjustable to dial down the pressure.
all is well and things run smoother and still cycles reliably. easy fix.

Thanks for the heads up. I will keep an eye on the brass casings and see if there is any brass shavings left behind.

Chad