[Spikes1540]

Ive been building the black rifle for about 5 years now for myself and others im not a novice builder but still have plenty room to expand my knowledge of the weapon lol. After 17 builds ive never had an issue that i couldnt resolve i usually build Frankenguns if you will lol with high end parts im currently working on a middle of the road build for a guy whose only request was do not spend over $1000 kinda hard to do this day and time and still come out ahead on the build lol. Im having major misfeed issues and ive tried everything i know to do any help would be appriciated the weapon will run like a top for about 20 to 30 rds then misfeed after every shot it will extract the spent case every time but will not pick up the next round the hammer will reset with the misfeed everytime and with only one round in the mag the weapon holds the bolt open properly after it is fired ill list the parts used and the test that have been performed.

RIFLE SPECS

*YHM STRIPPED LOWER
*YHM STRIPPED UPPER
*STAG ARMS BCG
*STAG ARMS GAS BLOCK
*STAG ARMS GAS TUBE
*ATI BUFFER ASSEMBLY
*WINDHAM WEAPONARY LPK
*WINDHAM WEAPONARY UPK
*STANDARD NATO M4 5.56 MILITARY BARREL

TESTS PERFORMED
* Tried several different mags Pmag, Troy , & Steel mags... Same misfeed
* Tried several types of ammo PMC, Lake City, Hornady, & even Wolf... Same misfeed
* Tried a few good cleanings with different lubes DriLube, Rem Oil, & Break Free... Same misfeed
* Tried a three BCG's Stag, RGuns FA profile, & WMD Nickle Boron FA profile... Same misfeed
*Tried Different Buffers & Springs Daniel Defense, Spikes Tactical ST2, & ATI... Same misfeed
*Tried rechecking the head spacing everything looked great
*Tried the complete lower on another upper and it ran like a top... Which looks to me like eliminates the Buffer Assembly & anything else lower receiver related.
*Tried Upper receiver on a different lower... Same misfeed
*Tried removing gas tube and block and cleaning both out, & tried checking gas port alignment by putting some foaming cleaner through the gas tube after one good spray i had foam coming out the end of my barrel...
By the weapon catching the bolt back after an empty mag and resetting the hammer after a misfeed im really leaning away from gas tube/block issues it cycles and extracts it just wont pick up the next round.

So I think Ive Eliminated
BCG
Gas Block/Tube
Ammo
Mags
Lower Receiver all together

Whats left change the barrel? I will greatly apreciate any help

 

[TacticalGenius]

Sounds to me like it could be the upper is out of spec somehow, or it could be a gas port issue as well. I had a 18" barrel for my 6.8 that I cut to 16" and I had a similar issue, it would fire and the bolt would be driven rearwards and sometimes it would fully eject the spent casing, sometimes not. If it managed to eject the casing, it would usually jam when feeding the next round. I ended up having the gas port enlarged a bit to allow for more gasses to cycle the action and that solved the problem.

I would see about enlarging the gas port, or if that will cost as much as a new barrel, replace the barrel. Actually, you may want to swap barrels from another upper to this upper just to test this theory out, that way you will know for sure. What make is the barrel?

 

[thinder]

I had a similar issue on my dissipator(16" barrel with rifle length gas tube= short dwell time). It would cycle and the hammer would fall on an empty chamber. My issue was resolved with good ammo. But I figured it was bcg speed issue. Try a different spring, heavier or lighter. Then try a heavier buffer. I also just lubbed the hell out if it and shot it a few hundred rounds that might have helped too.

 

[Spikes1540]

I've tried a few different buffers and springs which didn't change much. I'm unsure about the make of the barrel I got it cheap from an army surplus guy just stamped NATO 556.

 

[thinder]

It's got to be dragging in the barrel extension for some reason, slowing the bolt down. Check in there for burrs or dirt.

 

[Spikes1540]

Thinder I'm really glad that you said that I questioned a burr in the barrel extension but kept telling myself that a burr wouldn't cause this lol now I can justify pulling the barrel off I have another barrel I guess I'll just swap em out like Tactical Genius mentioned earlier. I'm out of town till tomorrow evening after the barrel swap I'll post some feed back. Thanks all and if anything else comes to mind I'm always open to ideas.

 

[woodstock]

I don't see timing as being an issue. If the bolt is traveling far enough to the rear to lock and to reset the hammer then it should be traveling far enough to strip a round from the mag.

 

[Spikes1540]

Woodstock I agree 100% the bolt and lower run great on my Spikes upper, the head spacing and gas system has been checked and re checked

 

[Spikes1540]

Guys swapped the barrel out and it fixed everything the gun runs like a top thanks everyone for all the input everyone was very helpful

 

[BRL]

...So I think Ive Eliminated
BCG
Gas Block/Tube
Ammo
Mags
Lower Receiver all together

Whats left change the barrel? I will greatly apreciate any help

So you narrowed it down, pretty much from the start.

Good job!

Too small of a gas port hole maybe?

 

[Spikes1540]

I'm not sure I got a punch that is the size of a gas port and it fit all the way through the gas port I'm thinking a burr In the barrel ext causing the bolt to jump up I'm taking it to a gunsmith and gonna see if
He can smooth it up for me and let me try it again I got 3 more builds people are waiting on so I could def use the barrel.