Is my ar short stroking

[Caliper_Mi]

Went to the range sunday after a good cleaning. Same result. Every sixth or seventh roung was a failure to eject. Tried 3 different magizines. American eagle 556 ammo & federal 223 ammo. Same result any ideas

Where do the empties land when it ejects? Also, is it reliably locking back after firing the last round?

 

[HARRYOKOKO]

Empty rounds land about 4 oclock which is good since iam a lefty shooting a right handed ar. Everything on this rifle is from the factory if it was a spring problem it would have started this problem right from the start would it not? The only thing i have done to this rifle is add a optic, flashlight

 

[MistWolf]

Mist wolf, I have had that problem and fixed it with a heavier buffer. The bolt would attempt to extract the round but since pressure was to high in the chamber it would not fully extract and was still there on bolt closing. Also replacing the spring with a stronger one made it worse. It may be over gassed as well. In either case slowing the bolt will help. The best way is a heavier buffer. If the spring is too strong that will also cause short stroking and the bolt to close too fast. That has been my experience. If you have a better idea let's hear it and why.

If the carrier is moving so fast, the empty hasn't enough time to make it out of the ejection port, you'll know it. Long before the carrier reaches those kinds of velocities, the carrier will be hitting the hammer back so hard, a sharp, stinging slap will be felt in the trigger bow. I can tell you from experience, it will be a very painful stinging slap.

When I built a shorty AR with a 10.5 inch barrel, a carbine weight buffer was used. Because the gas port was .083 inches, it was over-gassed and carrier speeds were too fast- fast enough that I felt a painful slap through the trigger bow. I did not experience any failures to extract or eject but it did send the brass into the next area code.

The carrier only has to travel about halfway back until the mouth of an empty will clear the leading edge of the ejection port. That gives the empty plenty of time to eject. Faster carrier speeds do not cause ejection problems, it only uncovers existing or impending problems. One thing that must be kept in mind when troubleshooting- Failures don't always just suddenly start. Springs don't always just lose tension all at once. Extractors wear over time. Rifles don't usually work fine until they suddenly start malfunctioning.

An AR will start to get an occasional malfunction, but the malfunction gets dismissed as a fluke. In reality, it's an indication that something has reached the end of it's useful life and is on its way to failure.

Extractors & ejectors and their spring don't wear away all at once. They may wear to the the point that they cause malfunctions when carrier speeds are on the high side, but work fine when carrier speeds are slowed down. Adding a heavier buffer or lighter spring may drop speeds enough to allow a worn extractor or ejector to work reliably again, but the wear is there and will continue and more malfunctions will occur.

It's human nature to think that because we change something (buffer weight, action spring rate) that makes a problem go away (empty cases again are completely ejected), the problem was caused by something else (carrier speed was too fast to allow empty case to clear ejection port) when what it really does is mask the true problem (weak ejection and/or extraction)

 

[kBob]

Harryokoko,

Check your PMs.

-kBob

 

[justin22885]

sounds to me like either a short-stroke or a weak ejector spring.. short stroking can be caused by not enough gas to the system, too heavy of a buffer spring, friction caused by misalignment of the upper and the buffer tube, underlubed, overlubed.. but it happens after 6 or 7 shots so it occurs after its been fired a few times first... i think it could be gas system related.. what ammo did you shoot it in before these problems occured?

 

[d2wing]

You have a point Mistwolf, I should have mentioned I also ungraded to a BCM bolt extractor and spring. It shoots anything fine now.

 

[HARRYOKOKO]

Been shooting all types of ammo,all brass though. The bolt locks back after the last round however sometimes even the last round casinig does not get out of the ejection port. Just laying backwards on top an empty mag. Been shooting everything from black hills mk262 77 grain on down to brand names i don't even remember. Mostly american eagle 556 55 grain

 

[justin22885]

so it gets far enough back to lock open, but doesnt kick the round out.. it just sits there.. take your ejector out, clean it, clean inside of the bolt, put it back together with a light amount of lube and try again, if it still fails, buy a new ejector spring

 

[carbine85]

Remove the sight block and check the gas port size and get the parts to refresh your bolt. The problem should go away assuming you have checked what's mentioned above.

 

[goon]

An extremely cheap thing to try is a new extractor and spring. I've seen them give up on abused basic training M-16's after a lifetime of rounds and on new upper end AR's after just a few hundred. Sometimes you get a bad part that just gives up way too soon. I'd get both, try the spring first, then the extractor if needed. It's like $20 to try.

 

[justin22885]

it sounds like its extracting just fine and the bolts traveling far enough to kick the rounds out.. its an ejector problem