AR weird cycling issue................questions.

[CCW]

Ok, this may get confusing but here goes.

Rifle 1.
Yankee Hill Lower and Bushy Commando Upper. ACE Skeleton fixed stock. Magpul PMAG.
Rifle will fire once, maybe twice, then FTF, leaving a small ping in the primer. Sometimes it will fire once and not recycle. Sometimes it will fire 3 times and then stop recycling.

Rifle 2.
Bushy factory A2. Magpul MOE adjustable stock.
Rifles cycles flawlessly.

Ok, I took the upper off of Rifle 1 thinking I may have a gas tube issue and installed it on Rifle 2 lower and it functions flawlessly so the problem must be in the Yankee Hill lower somewhere. Is it safe to assume the ACE fixed stock my be the culprit? Buffer maybe?

Any advice would be appreciated.

 

[pupdawg]

Re: AR weird cycling issue................questions.

Sounds like it. Why dont you swap the A2 onto the YHM lower and see how that works. If it runs fine then I guess its safe to say something might be wrong with the ACE stock or its components.

 

[kilo7788]

Re: AR weird cycling issue................questions.

Look at your hammer spring and make sure it is straight.

 

[CCW]

Re: AR weird cycling issue................question

Ok, swapped just the buffer springs and Rifle 1 functioned flawlessly with Rifle 2's buffer spring. The one in the Rifle 1 rifle was 11" and the one in Rifle 2 was 2.5" longer so I guess I need a longer buffer spring. Anyone know what the standard CARBINE buffer spring length is supposed to be?

 

[CT]

Re: AR weird cycling issue................questions.

First, make sure the recoil spring is the correct length for the ACE stock - either rifle or carbine length. I personally don't own an ACE stock but someone on here will chime in on correct recoil spring length ....... probably rifle length.

And, as you guessed, make sure you have the correct buffer for the ACE stock.

Check fire control parts closely in YHM lower. Did you buy the lower as new/factory assembled or from another owner?

Check/replace each of these parts preferably one at a time:

1. disconnector
2. trigger
3. hammer
4. selector

If you didn't buy it as a new/factory assembled lower and there is a possibility of used fire control parts, this maybe the answer.

Simple process of elimination and good luck - you'll figure it out with patience and parts!

 

[CCW]

Re: AR weird cycling issue................question

Would a 2.5" spacer be in line or should I replace the spring?

 

[CT]

Re: AR weird cycling issue................questions.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CCW</div><div class="ubbcode-body">Ok, swapped just the buffer springs and Rifle 1 functioned flawlessly with Rifle 2's buffer spring. The one in the Rifle 1 rifle was 11" and the one in Rifle 2 was 2" long so I guess I need a longer buffer spring. Anyone know what the standard CARBINE buffer spring length is supposed to be? </div></div>

Just measured one on the bench, its not new but measured 11".

 

[CCW]

Re: AR weird cycling issue................question

Thanks! So it sounds like I need a Rifle length buffer sprimg, which is what Rifle 2 has.

 

[CT]

Re: AR weird cycling issue................questions.

Replace the spring. Call DPMS if you don't have one and ask them to ship in a manilla envelope. Cuts shipping down to about $1.

 

[CCW]

Re: AR weird cycling issue................questions.

Excellent, thanks!

 

[CT]

Re: AR weird cycling issue................question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CCW</div><div class="ubbcode-body">Thanks! So it sounds like I need a Rifle length buffer sprimg, which is what Rifle 2 has. </div></div>


Ummmm, unless I'm misunderstanding, it sounds like you need a rifle length recoil spring - not a rifle length buffer tube. The ACE stock probably already has a rifle length buffer tube and using a carbine length recoil spring was the source of the problem.

Make sense?

Ok, you knew what you were talking about - just saw you edited to change.

Good Luck and have fun with the AR.

 

[toygunner]

Re: AR weird cycling issue................questions.

If the gun malfunction is on the 11.5 upper you may need to increase the gas port in the barrel. You can drill it to .092". It sounds like it is short cycling (not enough gas). I had a similar problem and this corrected it.

 

[CCW]

Re: AR weird cycling issue................question

Problem solved. Spring length was the problem. Thanks for all the help! Here is the mischievous pair!