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

98's 6 ARC 12.5" Pistol


Recommended Posts

So, I DID snag one of the Faxon 12.5" 6  ARC barrels, a couple weeks ago, when they dropped.  :thumbup:  I did this for two reasons. 

First, I built an 18" Grendel SPR-type rifle several years ago, and it knocked my socks off with how well it did at distance (850 yards).  Right after that, the Grendel Forum was doing a group-buy on 12" Grendel barrels, and I missed that one barely, so I bought a Faxon 12.5" Grendel barrel, publicly released.  Built that thing up, and right after it was built, we had a Spring Shoot...  and me, @Matt.Cross and @JBMatt shot that short little bastard at 850 yards with 10.6 mils of dial on the 4x Leupold scope.  FLOORED, with it's performance, that it even got out there, accurately... 

Second, I built a 6 ARC 18" SPR profile barrel from Ballistic Advantage, as soon as this cartridge was announced, on 3 Jun 2020.  I had the barrel about a week later, and had a gun together mid-July last year, and was shooting it. Blows Grendel away, for distance. Ran that bastard out to 850, and it was a pretty good difference - but it was also 105* when we were shooting.  Weird ballistics, in that kind of heat - but it did better than the Grendel did. 

So, this all ties into Grendel-work, on 18" SPR BA barrels, how that ties into the Faxon 12.5" barrels on Grendel for comparison against it, and the initial 6 ARC work with the BA SPR barrel...  which is a WINNER!... 

Yep, pulled that Faxon 12.5" Match barrel for the ARC...  I have a plan for the gun, and it will be badass.  But, I ran load development on the 18" ARC, and managed to get better groups over the Hornady Match 108 ELD-M ammo, on my 18" gun with my own handloads, and at a lower extreme spread.

Hornady Match loaded ammo was 2616fps with an ES of 48, and I worked up the handloads (with Accurate 2520) to 2680fps and an ES of 41.  That works.  That works into a load in the 12.5" of 2493fps...   Which is just NUTS!




If all this works out like the math says it does - this is a supersonic load to 1,050 yards, from a 12.5" gun. 

There's more coming...  hold onto your pants...  :banana:

Edited by 98Z5V
Link to comment
Share on other sites

  • Replies 76
  • Created
  • Last Reply

Top Posters In This Topic

3 minutes ago, ARTrooper said:

I will be getting a 16” barrel so I can make it a regular rifle build. 

finding matching upper and lower has been the problem for me.

In that case...


A little cheaper at Brownells before tax and shipping


Edited by Armed Eye Doc
Link to comment
Share on other sites

What's been referenced above would make a very solid build.  Very solid. 

Having troubles myself, finding parts, I broke from my comfortable pattern of Aero uppers and lowers, Aero handguard, Armalite springs, this and that.

This is an AR15-based gun, there is a pattern, and all parts fit, unless that particular company just flat-out sucks.  All parts work together.

I had the LaRue 6.5G BCG sitting here from the 18" 6 ARC build - that's in here.  Bought the Faxon Gunner 12.5" barrel.  Gun Pusher John has Ergo complete lower parts kits that included a grip - and man, let me tell you, that is a fine lower parts kit.  He also had the Strike Industries extended charging handle, and he saved me an Aero lower, of the X15 markings.  Bought a few Shockwave Blades several months ago - getting ready for this pistol-revolution by JoeBama and the BATFE...  Also picked up a few KAK Shockwave Blade pistol receiver extensions.  Had the Sprinco White spring here from the LaRue 6.5G kit (wasn't used in the 18" 6 ARC, went VLTOR A5 on that). Been sitting on an OLight Odin Mini since those came out.  Went with GunTec USA for the 12" rail, and found a ZRO Delta upper receiver on JoeBob's Outfitters for $65.  Had an H2 buffer sitting in the parts box, so I'll try that out in this one.  Still needed an ejection port door and a couple small things, and I nailed a Timber Creek billet port door at Sportsman's Warehouse last weekend - along with those other little small parts.  Gun Pusher John has the scope on order for me, but I'll still need a LaRue LT-158 mount for it.  Other than that, I have a 12.5" 6 ARC gun.

Getting hung up on brands and parts right now is just crazy - GET the good parts that you absolutely NEED - and get the other stuff where you can find it, here and there.  There's really no time to sit around and wait for your perfect parts list to become available - not in these times. 


Edited by 98Z5V
Link to comment
Share on other sites

2 minutes ago, ARTrooper said:

@98Z5V what do you suggest for a buffer weight on a 16” 6mm ARC, mid length gas system, that I will be running suppressed?

Just start with whatever AR15 parts that you can find, brother - for real.  It's probably gonna need an H3, when it all shakes out.  Right now, no kidding, I'd be grabbing whatever you can grab, and get the gun running - especially if you have the money.  That Bushmaster setup linked above is excellent - get that, and change what you wanna change later - if we still have parts available "later."  In the old-skool days of ARFcom, "if it wasn't ABC, it was SHIIT!@"...   "ABC" was Armalite, Bushmaster, and Colt...  To them, everything else just plain SUCKED. 

Link to comment
Share on other sites

With the current political climate, I might have guessed right.  Here's the 12.5" as it sits.  Done.  And TODAY, JoeBama is talking about a push for Gun Control...  Hmmm...  imagine that happening... 

6 ARCs, Big Brother, Little Brother.  The LaRue 18" and the 12.5".


The OLight Odin Mini is a badass little 1500-lumen weapons light, too.  Never talked about it, but I've got two of them, from many months back now.



Other side of the 12.5". 



AZ sunsets are badass - even when you're taking the sunset-pic going 80mph.



Link to comment
Share on other sites

1 minute ago, ARTrooper said:

Once it is built I am gonna have to beg you for ammo. Haha. 

No way - you tried that on the .260.  I need to get you into reloading, because I'm not giving away free ammo.  During a shoot is one thing, if someone is running low.  Supplying a guy...   Nope.  :bitchslap:

Image result for give a man a fish, teach a man to fish

Link to comment
Share on other sites

22 minutes ago, Armed Eye Doc said:

I thought there was another one.  @willbird has one also.


@willbird is getting it going - but I know @DayWalker damn near has a whole gun already...  and he's dragging his feet... 

Doesn't matter, though - he's still WAY FASTER at building a 6 ARC, than his Dad is at building a Mk12...  I'll just leave that right there and let it ferment...   :popcorn::laffs:

Edited by 98Z5V
Link to comment
Share on other sites

Three things sealed the deal for me on this one. 

#1.  18" Grendel is amazing.   Second Grendel was 12.5", and it was mind-blowing, what it could do., compared to the 18".  What I saw with Grendel performance, led me down the road to 5 Grendels.  Shiit y'all not a bit.  There's another 18" "lighter" gun, than that first SPR-ish heavy kinda-Mk12 gun I built, then a 16" Mod H Grendel, and finally a M4 16" Grendel.  It's a sickness, what that cartridge will do to a man...

#2.  Built a 6 ARC right away, and wanted to keep it as close to the original 18" Grendel SPR, and the 18" .224 Valk SPR as possible, for comparison purposes, and the ARC smoked them both.

#3. This article from RECOIL Mag...  Pint Size Precision, #51 in the mag history - they ran with the 11.5" ARC, for this one, and it did great.





I already knew what I could do with a 12.5" Grendel.  I saw what I saw with the 18" ARC.  Faxon (maker of the exact same barrel profile as my 12.5" Grendel) drops the 12.5" ARC barrel.

Done.  Right then.  I'm ALL IN.   :hail:

Link to comment
Share on other sites

2 hours ago, ARTrooper said:

Lol. I would pay you... 2019 prices 🤣

My time is worth way more than that - to me. You need to find your own ammo, or buy reloading equipment. I'd double-charge you at a minimum just for components, and that's on a JoeBama price scale.  That's not personal - it's truth.  It's too much trouble even FINDING the stuff that I need.

Even finding reloading components right now - powder, primers and projectiles - is a challenge.  I'm damn sure not spending my time searching, buying, and shipping - stuff to make you ammo. 

Don't take that personal.  Buy a reloading press, and commit the time to making ammo.  Sometimes, finding the time isn't easy.   :thumbup:

Link to comment
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...