Bought an EA E15A4B in Aug of this year.

Read through all FAQs and am not sure where my problem would go.

From the first mag fired, it "short stroked". IE empty would eject but it would not "pick up" the next round. Sometimes the bolt will go back far enough to partially feed the next round.

Have had 3 bolts/carriers, 3 types of ammo, and numerous mags.

Have even pulled the gas tube and blown it out with compressed air. Checked gas post in barrel, its ok. Still does the same thing.

Really enjoy this rifle. Out of the box can hit clay birds off hand at 75 yards.

If this rifle was bought new from Armalite, get them on the phone and see if they want you to return the rifle to be checked/repaired. When you call then, request a pick-up from a shipping company so they pay for shipping if it needs to be sent back.

If you have just built up a receiver with a parts kit, then he is a checklist by the numbers from muzzle to butt stock to check for stroking problems.

1. Check to make sure that the barrel/ front sight gas ports are aligned and the gas tube has full flow.

2. Check to see if the key to carrier is tight, and not leaking.  Best to just pull the key, check for burs, and re-install using Blue loctite between the two for form a gasket.  Also helps to lap the two together if you have the time.


3. Make sure that the carrier moves freely in the upper.  You should be able to open the carrier pull the carrier back with your finger, and then let the carrier free drop down.  It should drop, lock, and slightly bounce back.  If you have some carrier binding, stone the four bearing corners of the key, it will be the part that is binding on the upper receiver channel. If the bolt to barrel extension is the problem, then check to make sure that the lugs (bolt-extension) are lined up.  Also, any burs on the barrel extension may be causing the bolt to bind on ejection, so take a light and check the inside of the lugs, If needed, a jeweler file will work to clean the tool burs.

4. Pull the buffer and spring and check the tube for sighs of binding.  If you find straight scratch marks down the tube, then the end wind tip of the spring needs to be filed to prevent it from touching the tube.  If you have signs at the back of the tube that the total spring is scrapping, then take a file to the bumper roll pin (flush it) to keep if from grabbing the spring during compression.

5. Check the disconnector just behind the hook for signs that the hammer has been binding up the carrier/disconnector on the backstroke.  If you have a dent/bright line, then remove .040 off the tail of the hammer. This will allow the hammer to ride lower as the carrier passes over the top.

6. Check the chamber for head space, caliber (223 or 5.56 Nato), and to make sure that chamber is smooth as a babies ass.  Any of the above items that are out of spec will cause the case to stick to the chamber walls during ejection, and delay/bind the case from being cleanly ejected out of the rifle.

7. Keep the upper bearing surfaces lube with CLP until they mate.  CLP allow the surface to mate without the Parkerizing and anodizing building up and binding the action.  Once mated, you can run the rifle dry, but a light coat of CLP will dissolve the building up of carbon fouling to keep the rifle running.

Bottom line is when I get a new rifle, I find it just easier to strip it down, and put it back together fitting/checking all the parts.  When building rifle kits, I request that all parts are stripped (nothing assembled), which allows me to fit/check all the parts as I build.

If this is your first rodeo with the AR rifle system, and you bought the rifle new and complete, then take a look at the items listed and see if you feel comfortable doing a little smiting.  
[B]The one thing that you do not want to do is to go hog wild destroying any parts; this will void the warranty on the rifle.[/B]

[url=http://ar15.com/forums/topic.html?b=3&f=4&t=173512](Another) Gas system problem [/url]

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