Help with AR's

[Ed Deegan]

Have a couple of issues with my rifles:

AR-15. I think is the rifle attempting to double. Ammo is Fed 55 grain. Fire rifle, and when I attempt to fire the next round, the hammer has gone back forward during the firing sequence so you cannot fire again, and the primer for the fresh round (when extracted) shows a light hit. Manually operate the rifle and it will fire. This happened 4 times out of 20 rounds fired. Should I start looking in the trigger group to solve this issue?

Next rifle is an AR-10. Ammo is South African, the bolt is not extracting the fired case. Could this be the spring on the extractor needs replacing?

Thanks in advance.

Ed

[EkuJustice]

what kind of rifle? What kind of trigger Factory or built gun

Edited February 19, 2012 by EkuJustice

[Chris Keen]

How long has it been since you gave it a good cleaning? Wonder if the sear & hammer engagement could be dirty? First thing I would do is pull the top end off, and spray some Rem-Oil or other CLP type cleaner into the trigger group, and give it another try. If you absolutely have to take the trigger group apart to clean it better, make sure to look up a Youtube video on dis./re-assembly prior.

[Charles Bond]

I have seen the first problem you describe result from a primer that fell out of a case into the trigger group so Chris' suggestion that you clean out that lower is sage advice. Your AR-10 problem is likely a dirty bolt or dry bolt.

[Outsydlooknin75]

IF you recently took apart your fcg, are you sure you put the hammer spring in properly?

Sent from my PG06100 using Tapatalk

[dmc_md]

The light strike on the primer is normal. This is from the inertia of the firing pin as the bolt closes. This is what causes slam fires on certain types of primers. It is not from the hammer falling.

The fact that your hammer is falling could be due to a problem with the disconnector. Empty your weapon, pull the trigger, and with the trigger pulled, recock. The hammer should stay back. If it doesn't, it's a disconnector problem. If it turns out to be the disconnector, do not fire the weapon until it is resolved. A worn disconnector will not make an AR fully automatic. It will, however, hurt you and the gun.

Darren

[Shooter115]

For the AR15, as others have suggested pop the upper off and give the lower a good cleaning to make sure there is no debris. Then test the trigger to make sure it is functioning correctly. 1.Start with the hammer in the forward position 2. While holding the trigger fully depressed, cock the hammer. 3 At this point the hammer should lock back even with the trigger held in, if not you have a disconnecter problem. 4.If it does lock back, now release the trigger. The hammer should move forward slightly and catch on the sear. If it doesn't and falls all the way forward, you have a problem with the trigger/hammer. 5. If either the disconnecter or sear aren't functioning properly, get your rifle to someone knowledgeable for repair before attempting to fire it again. I googled this video for you that shows the processTrigger test

For your AR10. Disassemble and clean your bolt. Make sure you don't have any crud built up on the bolt face.Check the extractor for any chips or wear. Before reassembly make sure to clean your chamber well too, as a dirty chamber can cause extraction issues also. If it all looks good and you're still having trouble, try replacing the extractor assembly, they are cheap to replace.

[Bigpops]

Ed....send it to me, I'll fix it for you! (please include ammo)

[gunfrog]

Check to make sure you have "J HOOK" spring in the hammer. It is a small spring shaped like a J in the bottom center of the hammer, that keeps it aligned with the hammer pin. With out you have the problem you describe, the disconector will hold it back after first shots but hammer falls when you release the trigger and is not caught by sear.

[gunfrog]

AS for your AR 10, extraction problems with 308/762 ARs and surplus (soft brass) are at national crisis levels. If the chamber is tight, the problem is magnified. I had this problem on a dpms, and did all kinds of stuff. Finally got a full set gauges measured the chamber and it was min 308 length, I re-reamed it to near max 7.62 and polished. It had a 16" barrel with a short gas system, pluged that hole moved port to mid length., so pressure would be lower when extracting.

It is also important to keep chamber clean especially after shooting soft brass.

It would not hurt to use a stronger extractor spring, but better to create a situation where less force is required to get the brass out of chamber.

So consider checking your chamber out, but some simpler things to try first.

1. Increase buffer weight to delay unlocking, intent being to have extraction occur at lower pressure, in the hope the brass is not stuck to the chamber wall with as much force as it was a microsecond earlier.

2. Stronger buffer spring, same reason as above.

3. Polish the chamber, to reduce friction.