Newbie with ar 308 cycling issues.

[Donnysonshine]

Hello all and thank you in advance for any guidance. I just purchased my first ar 10 from a private build that was less than honest about said build. The bolt does not seem to engage the cartridge with enough force to chamber the round. It also does not pull cartridge from chamber to expel spent brass, the bcg just pulls back with the cartridge left to dangle. This is all being done without firing this weapon yet. It is an aero build with 18” barrel and 12 (+/-) gas tube. The buffer tube is 7”, has a 3 1/4” buffer and a 36 coil spring. I got the seller to replace the misrepresented bcg with a true aero bcg. This did not help. I assume it is because the buffer(and maybe spring) is too long for the 7” buffer tube, but not sure. The buffer now reads dsi c 556 4.5 and is for an ar 15 I again presume. Should I just get a longer buffer tube, or should I order a 2 1/4” buffer and spring from aero? Thank you again for any assistance!

Don

[DNP]

You’ve obviously figured out a good portion of it. You’ll probably get the recommendation to pick up an Armalite buffer tube, buffer and spring. You can sell the other one or hold on to it in the pile for an AR15 build. Start there, lube the hell out of it and see what it does. 

Edited January 1, 2021 by DNP

[98Z5V]

3 hours ago, Donnysonshine said:

 The buffer tube is 7”, has a 3 1/4” buffer and a 36 coil spring.

This is the cycling issue, right here - all of it. Was that 7" number you put out the overall length of thte receiver extension, or the internal depth of the extension?  Doesn't matter, either way.  You need to be running a 2.500" long buffer with the 7.000" internal depth carbine receiver extensions.  Your buffer is 3/4" longer than that, and won't le tthe BCG cycle fully. 

[Donnysonshine]

Yes, you are correct. It is the 7”internal measurement of the buffer tube. So if I get a 2.500” carbine buffer tube and associated spring, I should be gtg with this portion of the rifle? It is somewhat ironic that you, 98z5v, answered this topic as it was after reading a couple of your responses to topics that inspired me to sign up today. Thank you for your insight. 

Edited January 1, 2021 by Donnysonshine

[shrade]

You might contact Clint at Heavybuffers.com He has a CAR-10 buffer and spring for the 7" extension. Sure made my DPMS Gen 2 Recon run nice.  

[edgecrusher]

1 hour ago, Donnysonshine said:

Yes, you are correct. It is the 7”internal measurement of the buffer tube. So if I get a 2.500” carbine buffer tube and associated spring, I should be gtg with this portion of the rifle? It is somewhat ironic that you, 98z5v, answered this topic as it was after reading a couple of your responses to topics that inspired me to sign up today. Thank you for your insight. 

He is a shining star with a rough exterior. Gives good hugs though I’d you get past the no pants thing....

32 minutes ago, shrade said:

You might contact Clint at Heavybuffers.com He has a CAR-10 buffer and spring for the 7" extension. Sure made my DPMS Gen 2 Recon run nice.  

Clint is an awesome guy with a beautiful product. I only run his buffers. You pay upfront for long term stability and confidence in a superior product.

[ARTrooper]

@Donnysonshine you can get a buffer from heavybuffers.com and/or a nice sprinco spring. These companies are great and different combinations could get your rifles running properly, it just may take some trial and error.

The other route is what DNP said might get recommended. Get an armalite ar-10 6 position receiver extension kit for $75. Armalite has been getting these rifles correct for decades. When I did this I had to take out a small notch with a dremel to get the tube to seat at the correct depth in my aero precision lower and my buttstock doesn’t fully collapse by about .75” (buttstock not meant for armalite). But I saved around $100 or more and it functions flawlessly. I don’t mind the little bit the buttstock can’t collapse because it is more ready for my shooting position. I wouldn’t of made a different choice unless I was rolling in money.
 

If you don’t care about the savings, check out heavybuffers.com and sprinco.com, with their parts you can easily get a functioning system.

[98Z5V]

3 hours ago, Donnysonshine said:

Yes, you are correct. It is the 7”internal measurement of the buffer tube. So if I get a 2.500” carbine buffer tube and associated spring, I should be gtg with this portion of the rifle? It is somewhat ironic that you, 98z5v, answered this topic as it was after reading a couple of your responses to topics that inspired me to sign up today. Thank you for your insight. 

I'm the AR-Gun-Whisperer, man. It's what I do.  With enough (proper) information from someone that's having issues, it's not hard to figure out.  You gave that information, and I thank you for that.

2 hours ago, edgecrusher said:

He is a shining star with a rough exterior. Gives good hugs though I’d you get past the no pants thing....

Don't be afraid to publicly admit...   that the Pants-Down Hug was right up your alley...   Figuratively - not Literally - of course...