Jump to content
308AR.com Community
  • Visit Aero Precision
  • Visit Brownells
  • Visit EuroOptic
  • Visit Site
  • Visit Beachin Tactical
  • Visit Rainier Arms
  • Visit Ballistic Advantage
  • Visit Palmetto State Armory
  • Visit Cabelas
  • Visit Sportsmans Guide

Aero/Sig Shorty 308

Recommended Posts

Wanted a DI gun to replace my Sig P716 jam-o-matic. When I saw CDNN clearing out the 12.5 inch Sig barrels used for the P716 I figured what the hell. The Sig parts are mostly DPMS compatible and CDNN had a bunch of them including the bolt. Gas tube length was the only big difference I had to deal with. Parts list;

Aero M5 blem receiver set and 10 inch rail, Tactical Grey Cerakote

Sig 716 12.5 inch barrel, chrome lined, .073 gas port

D. Wilson Carrier and firing pin with a Sig 716 dual ejector bolt.

Cotton Arms Adjustable Gas Block 

11 inch gas tube custom made by White Oak Armament.

Vltor RE-10/A5SR: A5 Receiver Extension (had to add 50 cents)

PWS MOD2 Carbine Buffer - H3 5.5 oz

Tubbs Flat Wire Spring

LaRue MBT trigger

DPMS upper parts

Aero LPK

Magpul MOE-K2+ Pistol Grip

PSA branded SB3 adjustable pistol brace

This build comes in just over 1 pound less than the P716 at about 8.5 pounds. Much better balance than the 716 and more rail length to work with. The "brace" being adjustable and using a carbine extension tube is the schit! I was thinking the port would be small but no way, I had to crank the gas block way down and it isn't broke in yet. 25 rounds down the pipe and no malfunction except the two fired at the tightest setting of the gas block, ejected but did not lock back. Worked with Lancer and Magpul mags. The bore has to be dead on concentric with the threads, best looking suppressor alignment I have seen to date with the gauge looking dead nuts center. Hope to get the PA 4x16 on it this weekend and see what it will group as well as check out how it reacts to some heat.


Brass ejects about 3-4 o'clock with no suppressor, no swipe, pretty light primer strike;


With the suppressor they land about 1 o"clock and show a little ejector smear;


Share this post

Link to post
Share on other sites

Finding the Lancer mags not so reliable in this rifle pistol. Ran 50 rounds of M80 ball today, Federal and some Austrian stuff. When using the lancer mags the bolt catch engages the carrier and not the bolt, when I cycle it by hand it grabs the bolt. Ran from high to low on the gas settings with no changes till it is choked down and doesn't cycle. With P-mags it grabs the bolt 100% unless the gas is choked way down. On occasion it will drop the Lancer mag out on the last round, I was going to swap the mag catch for an Armalite A model catch but with the bolt catch issue it looks like I will just stick to P-mags. Possibly I have an out of spec Lancer mag.

Accuracy was nothing great but didn't expect much with M-80 ball and using an early PA 4x16 Mil Dot scope that I have never gotten good results from, has a VERY tight eye box, very tight eye relief, and a funky parallax adjustment. Hoping to pick up a more permanent optic on holiday sales coming up.

Share this post

Link to post
Share on other sites

So what is the story on the Sig barrels ?? What does one need to to to use one in AR 308 ?? Kind of looking at the Aero upper/lower myself.

"Only fits Sig Sauer 716 rifles. Will not work with any SR25 or AR10 platform."


Share this post

Link to post
Share on other sites
46 minutes ago, willbird said:

Forgot to say nice build :-).

But back to the Sig bbl, does it require the sig bolt to match ?? The custom gas is not a super big deal I suppose.



I am running the Sig bolt in it but it headspaces and runs on a D Wilson 308 bolt as well. Gas block hangs over the step by a bit to line up the ports so if it were one of those blocks that has an opening in the clamping surface it may not seat well. An SLR gas block jig was a big help getting the dimples in the correct place. Just bought a second barrel when they had them for $49.99, DPMS style bolt headspaces on it as well. Don't forget to grab a 716 bolt catch as well, works in everything I have tried it in.

Share this post

Link to post
Share on other sites
1 hour ago, willbird said:

What did the gas tube end up costing for a custom ??

Right around $40, obviously custom with the polish and the very well done bends and ends. Mine was 11 inches but I highly recommend you measure with your gas block in place to be sure.

Share this post

Link to post
Share on other sites
24 minutes ago, 308kiwi said:

NICE :thumbup:

You forgot to tell us what suppressor you are running..........

I have a couple AAC SDN-6's.

Share this post

Link to post
Share on other sites
7 hours ago, jtallen83 said:

I have a couple AAC SDN-6's.

One is a reman, though...  :hornet:   :laffs:  I still can't believe how they wrote that up, and completely took care of you. That's just badass.  :hail:

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...