AR15 Extractor Donut [Archive] - Colorado AR-15 Shooters Club Discussion Forums

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b52buff

03-18-2011, 17:41

I just got a Stag Arms model 3 and there was no donut on the extractor. I looked at the manual for the model 3 and there is no mention of the donut nor is it pictured. I then looked at my manual for my LMT and there is no mention nor is it pictured. My LMT has a donut. Stag Arms is closed until Monday.

Can anyone shine any light on the purpose of the donut.

StagLefty

03-18-2011, 18:18

Just read this and realized your in MI-never mind going to Bowers as suggested earlier [ROFL1]

b52buff

03-18-2011, 18:24

Just read this and realized your in MI-never mind going to Bowers as suggested earlier [ROFL1]

No problem I just wanted to throw out the question to see what the purpose was for the donut. I have been to CO and it is a beautiful state. I will look up Bowers next time if I ever get that way again.

This is mind boggling that they don't mention the donut![Help]

Big Wall

03-18-2011, 18:32

The donut is an extractor upgrade. One of your guns has it and the other doesn't.

mc223

03-18-2011, 19:04

If you are not having ejection issues, dont worry bout it.

Unless you want to worry about it. You certainly can use one if you want.

I dont use the the o ring and never have had a need to.

trlcavscout

03-18-2011, 20:37

My BCM came with one in a bag, I havent put it on because extracting is one thing I dont have a problem with!

FireMoth

03-19-2011, 00:51

The donut increases extractor pressure, and helps prevent spring kinking that will lead to breakage (took out a spring that had been snapped in half just the other day).

Its not necessary, but it does improve function MOST of the time. Combined with an extra power extractor spring, it can prevent full bolt closure because the extractor wont snap over.
However, the most common problem with ARs far and wide is failure to extract, so i put them in as a fail safe in all of my ARs.

StagLefty

03-19-2011, 09:16

I will look up Bowers next time if I ever get that way again.

FireMoth is so good he does internet and long distance gunsmithing [Beer]

legaleagle

03-19-2011, 23:11

I have not seen a Stag with the donut. They seem to come with either a blue or black insert in the spring, which kinda does the same thing as the donut (or at least same theory). However, the donut probably generates more "spring" tension, although I have not actually measured the pressure between the two. More critically, the shape and fit of the extractor on the brass, combined with the leverage from the fulcrum pivot is more important - a bad extractor is not fixed with the donut, etc.

If you are not having issues, I would not worry about it. Too much spring pressure can be another problem, as mentioned.

YammyMonkey

03-20-2011, 00:05

b52buff

03-20-2011, 06:35

I have a big bag of those O rings. PM me your address & I'll mail you a few.

Don't just buy one from Home Depot. The rubber won't hold up to the heat, cleaning chemicals & (less of a concern) lube combo.

Thank you YammyMonkey but I already have some on the way. I have not taken my Stag Arms to the range yet. I will try it without the donut but my LMT has one so I will have spares for that one.[Beer]

espos1111

03-20-2011, 09:40

The o-rings (#60 BTW) from HomeDepot hold up quite well for a few thousand rounds. Even if you change them every 200 rounds or so, a bag of 10 is only $2.50. After that you shouldn't need one anymore, as the rifle should be well broken in by then. YMMV

FireMoth

03-20-2011, 10:01

I do strongly recommend using o-rings designed for fire arms. Depending on heat cycles, solvents, and exhaust gas interaction the rubber o-rings found at hardware stores can suddenly and catastrophically degrade.

Coming apart can bind the extractor causing failure to go into battery, failure to extract, potential damage to the locking seats, and even extractor breakage.

on top of lasting more than a 'couple thousand rounds' the important difference is how the fire arms intended ones break down when they do degrade, which is to go flat and get deformed a bit, but not break apart, or gum up like a normal rubber o-ring can.

Otherwise the o-ring designed to fix extractor problems suddenly becomes the reason for a catastrophic extractor failure.

You don't have to buy $10.00 o-rings, the ar type are cheap too. and its not worth balking over the pennies differences when it comes to keeping your gun running.

espos1111

03-20-2011, 14:33

^ I can agree with your statements except... I was not suggesting you use it for a "couple thousand rounds". I DO NOT recommend to anybody they do ANYTHING to their weapon that they are uncomfortable doing. I was in the USMC and am VERY comfortable around these weapons. When I break down the BCG I go through every piece. I also change the o-ring when I clean it, until it is broken-in. I have only had to use it on one pistol, as those are known for extraction/gas issues out of the box, never on my rifles. Also the o-ring/d-ring/doughnut could/should be removed after the chamber is broken-in. It is there for extra extractor power when the chamber is new and tight. On top of all that, It is easier it find a o-ring at HD to use to diagnose a potential problem instead of waiting for your parts in the mail, or finding a shop closer than a HD that is open and has one in stock.

Again, I am not arguing with you, I agree that you should use the proper piece of equipment for the job. I would suggest the o-ring to see if that is the problem, if it fixes it THEN order the correct part. If it doesn't look elsewhere.

Byte Stryke

03-20-2011, 15:26

I would suggest the o-ring to see if that is the problem, if it fixes it THEN order the correct part. If it doesn't look elsewhere.

I don't believe there was a problem per-se but instead a difference between two models was noticed.

espos1111

03-21-2011, 16:14

I don't believe there was a problem per-se but instead a difference between two models was noticed.
I figured there was no problem with his rifle, but a lot of other people read these for troubleshooting and help. I was just clarifying my first post about the o-rings for their knowledge.

b52buff

03-22-2011, 10:41