AR not feeding properly.

[hula]

All new parts:
Noveske Afghan barrel
Noveske upper and lower
Daniel defense lower kit
New P mags and standard mil spec mags (which feed my LMT fine)
Barrel torqued to ~35lb ft
Young chrome M16 BCG
Federal xm ammo
PMC ammo

Went out to fire today first time and had an H2 buffer in with Larue Magpul CRT kit and spring. Noticed it did not lock back after last round and thought maybe new spring with H2 was too heavy so switched to regular buffer. Still does not lock back after last round and have had jams up the ramp binding just below the shoulder of the cartridge. Also not feeding a cartridge off the ramp periodically. Magazine fit seems fine.

 

[johnsobr]

Re: AR not feeding properly.

Do you have a upper receiver cut for m4 ramps with a barrel that does not have m4 feed ramps?

 

[smrkovsky]

Re: AR not feeding properly.

Inadequate spring pressure in the mags could be the reason you’re having feeding problems. Maybe try running different mags.

The lock back problem could be caused by the buffer spring not allowing the carrier to travel all the way back and not allowing it to lock back on the last round. Try replacing it and see if the problem continues. Will the carrier lock back if you pull the charging handle back on an empty mag?

Also check the gas key bolts on top of the carrier. They may be loose which could cause feeding problems.

 

[PLeighton]

Re: AR not feeding properly.

One thing that often happens is the bolt catch can become bound up in the Lower Receiver.
The problem you describe is the only immediate symptom.

Check the bolt catch and make sure that it is able to move freely.
If it is hard pressed against one side of the receiver, take an appropriately sized punch and tap the roll pin the opposite direction until it is centered.

You say that you are using a Noveske Barrel and Upper Receiver.
Did it come assembled?
Are you using the gas block that shipped with the barrel?
If you are using a different gas block, check it for alignment.
(The stock Noveske gas blocks are pinned and cannot be misaligned.)

 

[johnsobr]

Re: AR not feeding properly.

Since your mags are new and you have tried different buffers, I would start looking at other things. I would start looking at simple things first and eliminate them first. Like Dr. Phil said start with bolt catch. Look at the cotter pin which retains the cam pin to make sure it isnt draging and slowing the bolt down.

According to Noveske it has extended feed ramps so disregard my previous post. One thing to consider is it is new and everything is tight. May just need a good couple hundred round break in to mate the parts.

If all the simple things fail I would start examining your gas system since it would most likely be the culprit for not cycling the action all the way. This still doesnt explain your FTF problem.

When you changed out your buffer did you use the same spring? Is the rifle lubed properly?

Only thing I can think of for your FTF problems is your bolt draging or a bad buffer spring. The H2 buffer does not seem to be the problem since according to your description you are not short stroking, just not locking back (with either buffer). What buffer tube are you running? Carbine or rifle? Are you using the correct buffer for your tube. A rifle buffer in a carbine tube would cause cycling problems. Just a thought.

Just ideas. anyone have any other ideas? Cmon lets get this rifle running!

 

[3O8Junkie]

Re: AR not feeding properly.

My Noveske only uses Armalite pattern mags?
Pmags, and the SR25 patterns that work in the LMT, don't work in Noveske's as far as I know?
I am by no means on top of everything that goes on in the shooting world, but am I missing something here? Are you saying you have a Noveske that uses Pmags and SR25 pattern mags?

 

[BOLTRIPPER]

Re: AR not feeding properly.

your rifle do not breathe right,,,,,,make certain the exhaust hole at the rear of the buffer tube (that screw with a hole in it ) is there.....or lacking that just make sure that the compressed air on the rearward stroke of the buffer goes somewhere

 

[KM375]

Re: AR not feeding properly.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ShooterMcGavin33</div><div class="ubbcode-body">My Noveske only uses Armalite pattern mags?
Pmags, and the SR25 patterns that work in the LMT, don't work in Noveske's as far as I know?
I am by no means on top of everything that goes on in the shooting world, but am I missing something here? Are you saying you have a Noveske that uses Pmags and SR25 pattern mags? </div></div>

Sounds like he has a 5.56 gun not the 7.62 gun that you have, but noveske did make a few 7.62 guns with the KAC, DPMS pattern early on.

 

[johnsobr]

Re: AR not feeding properly.

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=1721122

Found this post its worth a look too

 

[salmonaxe]

Re: AR not feeding properly.

Try a different bolt carrier. Try a different lower.

Sounds like short stroking. Sometimes it's over-gassing, sometimes it's under-gassing. SBR's can be finicky.

If you have one of those bolts with an o-ring under the extractor, try it without the o-ring.

 

[hula]

Re: AR not feeding properly.

Everything above noted and will run down the list in the am. The gas tube is the one that came with the barrel and clear. I included the link to the stock/buffer kit I used from Larue. I may try a standard carbine spring tomorrow. My feeling is the FTF is secondary to possible short stroking due to tight tolerances or buffer spring compression. I'll check the bolt catch also since I installed a B.A.D. lever from Magpul, although it seemed free to move. I'll let you know.

http://www.laruetactical.com/combo-magpul-ctr-mil-spec-stock-and-receiver-extention-kit

 

[DP425]

Re: AR not feeding properly.

That BAD lever may very well be a contributing factor

 

[HPLLC]

Re: AR not feeding properly.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DP425</div><div class="ubbcode-body">That BAD lever may very well be a contributing factor </div></div>

The bolt release extenders are junk. I would ditch it even if it had nothing to do with reliability, but you're right it might have an adverse effect on reliability.

Otherwise it would sound like undergassing, which might mean the gas port is too small, or the buffer is too heavy.

It may make sense to check that the spring is the correct length and number of coils. Perhaps an A2 spring would cause failure to lock back (longer spring causing the bolt to lose travel).

 

[PLeighton]

Re: AR not feeding properly.

Try it without the BAD lever installed just for the sake of troubleshooting.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Griffin Armament</div><div class="ubbcode-body">The bolt release extenders are junk. I would ditch it even if it had nothing to do with reliability, but you're right it might have an adverse effect on reliability.</div></div>I agree and also disagree with this statement.
In general, the extenders suck.
The Magpul BAD lever has been extensively tested and works extremely well when properly setup though.
It is very important that the BAD lever "wobbles" freely on the bolt catch.
It is designed that way to help make the bolt lock back on an empty magazine.

 

[RingSteel]

Re: AR not feeding properly.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dr. Phil</div><div class="ubbcode-body">The Magpul BAD lever has been extensively tested and works extremely well when properly setup though.
It is very important that the BAD lever "wobbles" freely on the bolt catch.
It is designed that way to help make the bolt lock back on an empty magazine.
</div></div>

I didn't realise that. Thanks for the info.

 

[hula]

Re: AR not feeding properly.

Problem solved.Went through everyone's suggestions and all checked out. Pulled out the buffer spring that came with the Magpul CTR stock kit from Larue.. As you can see in the photo left to right you have a carbine spring, Larue kit spring and a rifle spring for comparison. The kit spring is about an inch longer and stiffer. My thought is was intended for a lighter semi auto BCG and not a heavier M16 full auto BCG. So, I took the standard spring out of my LMT and H buffer and put them in the noveske build. Then put the heavier Larue kit spring with standard buffer in the LMT. Both ran like a champ with minimal recoil at the range. So it was a bolt mass/spring tension problem. My thought ids the Magpul CTR kit from Larue was intended for a semi auto BCG. I'll call to verify and I'm always more than happy to do business with Larue.

 

[edwin907]

Re: AR not feeding properly.

The only thing these "higher power" buffer springs are good for is jamming your opponent's weapon.
I have never seen a correctly built/gassed rifle run better with one. And a new not yet broken in rifle, definite capacity to jam.