PDA

View Full Version : Dueling 12.5's - build planning, ersatz-GL/SSC vs GAU-5 ASDW



Diamondback
04-06-20, 16:49
Stick, hope you don't mind me starting this here since you're one of the few experts on the subject.

As some folks will recall, I tend to be a fan of starting my builds based on proven military-issue engineering and then adapting based on my needs, NFA compliance or component availability. Right now I have the PDW role covered by a "Mk 18-ish" build, the C8 and M4 (under construction) have "Service Rifle/Carbine" taken care of, so I'm looking at something in between and the dueling options are various GL/SSC-based setups or a GAU-5 ASDW. Mainly we're discussing URG's here, the bottom halves will all be the same either way going together as a pistol--the questions there will be whether to go clone or improve via the A5 system, and whether or not to add a LAW sidefolder. (Primary mission on this build will be Home D, but I also like all my irons to be built close to something mil-issue that I can use for class Range Days when/if I break back into academia so it needs to be something that can pass for its military counterpart in a "shoot this, shoot its generations-past counterpart then write Compare/Contrast paper" role.) Other assumptions are that I don't really need to engage beyond about 200-300 yards, I prefer fixed iron sights and the less moving parts required to make ready to fire other than "flip safety off or charge" the better. (The only reason I use Diamondhead folders is I find them especially suited to my bad eyes--seriously, back in college the guys I shot with used to call me "Gun Tommy, shoots by sense of smell"--and if I could somehow jigger them into fixed or get DH to make me a non-folder adaptation I would in a heartbeat.) Other relevant notes, this build will be neither a grenade launcher nor a suppressor host.

Option 1: Midwest GAU-5
Pros: Off-the-shelf. Breaks in half with quick reassembly should a discreet-carry/transport situation arise. Longer BUIS sight radius.
Cons: Folding sights require deployment on top of assembly before shot. No "issue config" optic. (If I go this route and add an optic, I want it to be one that could hold zero through the knocks of a Martin-Baker Fan Club ejection and landing.)

Option 2: GL/SSC rumored variant, based on Centurion upper with 10.75" KAC URX-II rail
Pros: Components nominally available. Optic friendly. LPVO friendly if optics turn that direction. More rail than RAS.
Cons: Folder front sight requires deployment. Removal of gas block and some outsourcing to currently-closed pro smith for rail install and torquing required. Less rail than Centurion. URX-II getting hard to find and requires special tools.

Option 3: GL/SSC "Block 1," Centurion upper with M4 RAS
Pros: Simple, classic method. RAS is drop-in install I can do at home. Fixed FSB means less moving parts.
Cons: Limited rail space. LPVO pointless with FSB, so useful optics limited to RDS.

Option 4: GL/SSC "Ersatz Block 2" FSP, Centurion upper with C4 Pocket Rail
Pros: Off-the-shelf factory assembled option, when Monty has parts stock. Fixed FSP.
Cons: Requires 0.2" shim behind FH to restore FH/rail clearance geometry or use of a "non-standard" linear comp/blast shield.

Option 5: GL/SSC "Ersatz Block 2" Flattop, Centurion upper with 12" C4 Rail
Pros: Off-the-shelf factory assembled option, when Monty has parts stock. Longer BUIS sight radius.
Cons: Requires 0.2" shim behind FH to restore FH/rail clearance geometry or use of a "non-standard" linear comp/blast shield. Folding BUIS requires deployment.

Based on these possible options and their pros/cons, I'm throwing this out to Stick Nation for opinions... Any of you guys see any advantages/disadvantages each option may have that I've missed, or anything that should move some options up or down on preference relative to others? (Eventually I'd like both a "GL/SSC-ish" and an ASDW in the rack, but as it is the house already has more iron than shooters so we're adequately equipped and the second in same role would be a luxury.) Remember, this has to be an NFA-compliant "Pistol" or "Title 1 Other" build... which means probably no VFG, definitely none if outfitted with a LAW.

JediGuy
04-07-20, 00:21
The GL/SSC is just unique enough to be fascinating to me, plus a 12.5” upper was the first AR item I purchased.

But, I think if you want to be close to the original, you only have Options 1, 2, or 5.
Option 1 is cool in its own right and the easiest. I may get one of these eventually. Or not.
Option 2 is apparently/allegedly close to a version of a GL/SSC, but unnecessarily complicated.
Option 5 would be my selection. Personally, I’d probably go with the Forward Controls Design RHF4 11.5” (custom version of Centurion Arms C4) just to keep life simple.

Diamondback
04-07-20, 22:10
Thanks, JG. The RIS FSP was prototyped and assigned an NSN, I'm just not sure how many of them there were among the 125 SSC RIS's made--it might be a "Unicorn of Unicorns."

JediGuy
04-08-20, 08:20
If you get/have a picture, Id love to see one for those.

Diamondback
04-08-20, 10:47
If you get/have a picture, I’d love to see one for those.

Daniel Defense part number is DD-8050, NSN 1005-01-566-5284 for the rail or 1090-01-D12-0983 for the complete URG. Trying to find the SOPMOD Program PDF I saw the photo in again.

Hammer_Man
04-09-20, 11:32
The C4 rails are very solid, and only require basic tools to install. KAC URX rails are also very solid, but require a special tool to install. If you decide on the URX II, I'd be happy to install it for you, or lend you the tool.

Diamondback
04-09-20, 12:58
Thank you, HM--the URX is a lot of "ifs" at this point, as are all these concepts: *if* the project happens, *if* that option's selected and *if* I can find one. C4's, my plan would be to just have Monty's crew build and ship the entire URG as a complete unit other than shimming the FH.

Big question before even proceeding is if it's Time Zero, and you have a GL/SSC and an ASDW in the ready rack and have to pick one or the other, which one of the "midsize shorties" do you call upon to defend your home and loved ones?

TehLlama
04-10-20, 11:12
The DD GL/SSC has been my white whale for quite a while now... although for any masterkey type applications I'd realistically be trying to do with this, that particular rail isn't all that key.
Once I've let that go, realisticaly I'd want to be on a URX and use most of the length - without any dedicated underbarrel attachments, might as well make it as long as possible.

JediGuy
04-10-20, 11:13
They are both 12.5” barrels with quality components. If you want to keep in “closer to clone” status, I imagine the ASDW wouldn’t come with an optic. In that case, I’d grab the GL/SSC. But, other than that, I think the ASDW brings an additional, unique capability in its ability to be broken down.

Diamondback
04-10-20, 12:54
They are both 12.5” barrels with quality components. If you want to keep in “closer to clone” status, I imagine the ASDW wouldn’t come with an optic. In that case, I’d grab the GL/SSC. But, other than that, I think the ASDW brings an additional, unique capability in its ability to be broken down.

Even though it might not be "clone perfect," if I could find a compact red-dot that would plausibly hold zero through an ejection-seat ride and parachute landing I'd have no qualms racking it on. "Clone Correct" Elcan SU-230 for the SSC seems a bit big and heavy for CQB...

Hammer_Man
04-11-20, 07:33
Right now might not be the best time to shop for a URX II, as the Knight's Armament online store is closed right now due to Covid-19. They were the only place I could find URX IIs in stock when I was toying with idea of another 11.5" build.

IMO, if you're not a fighter pilot making your way on foot through hostile terrain, then a GAU-5 isn't really necessary.

Diamondback
04-11-20, 23:04
Right now might not be the best time to shop for a URX II, as the Knight's Armament online store is closed right now due to Covid-19. They were the only place I could find URX IIs in stock when I was toying with idea of another 11.5" build.

IMO, if you're not a fighter pilot making your way on foot through hostile terrain, then a GAU-5 isn't really necessary.

I don't think I've ever seen the URX-II in stock at KAC in the couple years I've been in the AR game, unsurprising since it's considered "2 generations obsolete". Re the GAU, part of its appeal is that it gives you almost a full M4 that can still discreetly fit into a Bug-Out/Get-Home Bag, alongside the "novelty" factor.

Hammer_Man
04-12-20, 00:50
I don't think I've ever seen the URX-II in stock at KAC in the couple years I've been in the AR game, unsurprising since it's considered "2 generations obsolete". Re the GAU, part of its appeal is that it gives you almost a full M4 that can still discreetly fit into a Bug-Out/Get-Home Bag, alongside the "novelty" factor.

They had them in stock a few months back. I almost ordered one, but I had other financial obligations at the time. I was very tempted though. I remember going as far as putting my CC info into their checkout screen.... You may want to call their office, and see if they have any you can buy over the phone...

I can agree with the novelty factor. If it suits your needs that's great.

Diamondback
04-12-20, 01:20
They had them in stock a few months back. I almost ordered one, but I had other financial obligations at the time. I was very tempted though. I remember going as far as putting my CC info into their checkout screen.... You may want to call their office, and see if they have any you can buy over the phone...

I can agree with the novelty factor. If it suits your needs that's great.

True... "needs" I have a Mk 18 and my trusty old 1911 for Bad Breath Distance and a C8 and soon M4 for "reach", anything more is just adding more options and "improving"--as it is we already have more systems than personnel to operate them. Eventually, I'd like one of each, so at this point the debate is more about prioritizing which is going forward first.

Stickman
04-14-20, 10:21
I need to get a group shot of my various 12.5"s. Here is the current configuration of her as she sits at the moment...

https://66.media.tumblr.com/f769949c3dc1b461d462728812470fe8/8acfe496c9d4c5b7-77/s1280x1920/f612b4b74c992e5cc566fe4b6d7b382edb3049b1.jpg


https://66.media.tumblr.com/e8a98e712f9c768b3806a15241c97d35/f0ffa68fa88f708a-e2/s1280x1920/055d0ed62bb90046857d0df9fcc5c8f86662aea7.jpg


https://66.media.tumblr.com/f326f12485b3af5d1aebfb6f942e7e5a/690f3310fa37d108-bc/s1280x1920/e2bd498bf7d4b0fd910359e31203df0f8a0f6d01.jpg

Stickman
04-14-20, 10:24
The GL/SSC is set up as primarily a daytime weapon, below is my primary night time/ bump in the dark gun in MK18 flavor.

https://66.media.tumblr.com/413387ca3e91186a595a564eff4435ef/254d9eb08474e21f-3f/s1280x1920/758068fc37ec71793b312180ebcf8e64ef4f6bf7.jpg

https://66.media.tumblr.com/6f01379ddc6dd5a6682cec2dc7f784a8/611ad64af029d571-ae/s1280x1920/edbb68487a2719e74f9ca177e9c2181edde4b50e.jpg

JediGuy
04-14-20, 11:38
Honestly, Stick, with options at 10.3/11.5/12.5 with good ammo, for practical purposes, do you see much point in anything longer than a 12.5 besides maybe an 18 SPR?

Diamondback
04-14-20, 18:06
The GL/SSC is set up as primarily a daytime weapon, below is my primary night time/ bump in the dark gun in MK18 flavor.

Ironic that the roles are reversed for our purposes... my Mk 18, once reconstituted onto a live lower, is on day shift because it can be more discreetly carried while anything bigger leaves rack only for Range or Bump-In-The-Night.

61763
This pic doesn't have the laser, tape, blast shield or left-side and brace-mount spare mags, but see anything you'd do differently or might be an NFA issue if this goes onto Live Iron? (Ready-to-fire length is 25.925 from A5 tube through to muzzle crown, though I'm not sure how the "unsafe to fire folded" LAW compares to irons that are meant to fire while folded. You know ATF, not happy if the rules are predictable...)

Stickman
04-21-20, 16:01
Honestly, Stick, with options at 10.3/11.5/12.5 with good ammo, for practical purposes, do you see much point in anything longer than a 12.5” besides maybe an 18” SPR?

Sorry that I missed this question. I think once we start to reply with yes or no, we get back to condensing that idea that we may as well all use 12.5s. It also brings up the question of ammo and by that point we are on the slippery slope to all arguing that "Stick sucks, we should just carry Mk18s".

JediGuy
04-21-20, 20:21
"Stick sucks, we should just carry Mk18s".

That would be interesting, since I believe you shared pictures of your go-to 10.3” carbine. I guess haters gonna hate.

Hammer_Man
04-24-20, 20:18
https://www.operationparts.com/kac-knights-armament-mid-length-urx-10-3-4-sr15-ar15-includes-built-in-front-flip-up-sight/

FYI URX II in stock at Operation Parts