Now that the URG-I is evidently rolling out to US Army Special Forces Groups, I thought I’d do a quick primer on it.
Definitions
So what is the URG-I? Is it “Block 3”, or maybe “Mk18 MOD 2”?
Not quite. URG-I stands for Upper Receiver Group, Improved. This is not to be confused with SURG, which is a separate programme:
Current public URG-I reference pics show an array of improved parts, used to outfit existing M4A1 long (14.5″ barrel) uppers. These improved parts have been spec’d specifically for USASOC – which stands for US Army Special Operations Command. This is a particular Army command and therefore does not span the whole of SOCOM.
USASOC’s elements (some of whom already have the URG-I) largely use the M4A1 with the Block II accessory package. Therefore rifles which utilise the URG-I are still Block II.
Keeping Up To Date With Developments
The very best resource for learning about the URG-I and how to clone it is this thread on AR15.com. It’s very long but it goes into way more detail than this primer will.
If you keep tabs on it, you’ll usually see new URG-I reference pics and discussion there first – well before the IG sharing pages – although @btl_ltw on IG is also fast and reliable.
Setup
Because the AR15.com thread is trustworthy, I’ll directly quote the 14.5″ URG-I setup recommended:
Lower Receiver Group
Lower receiver – M4A1
Receiver extension – standard M4/M4A1
Action spring- standard M4/M4A1
Buffer – H2
Grip – standard M16A2/M16A3/M16A4/M4/M4A1
Stock – SOPMOD
Trigger- Geissele SSF – P/N 05-102
Selector- Colt full auto ambi – P/N SP401017
14.5″ Upper Receiver Group, Improved – NSN 1005-01-671-3911
Upper receiver- standard M4/M4A1
Bolt carrier group – standard M16A4/M4/M4A1
Charging handle – Geissele Airborne Charging Handle in Desert Dirt Color with subdued markings- P/N 05-664S – NSN 1005-01-672-4803
Barrel – Daniel Defense 14.5″ mid length “GOV” profile with .076″ gas port – P/N 07-077-07308
Gas block – Daniel Defense pinned gas block which comes on their rifles and URGs
Gas tube – Daniel Defense mid length – P/N 04-013-18034
Hand guard – Geissele 13.5″ MK16 in Desert Dirt Color- P/N 05-650S- NSN 1005-01-672-4794
M-LOK rail section – Magpul 7 slot aluminum – P/N MAG582-BLK
Sling mount – Magpul QD- P/N MAG606-BLK
Muzzle device – SureFire 4 prong flash hider – P/N FH556RC
Suppressor – SureFire SOCOM in Dark Earth – P/N SOCOM556-RC
Rear BUIS – Matech
Front BUIS – Knight’s Armament Front Flip Sight in Taupe P/N 99051
Interestingly, the AR15.com thread lists the 11.5″ version of the URG-I as “issued”, although I haven’t seen any pics of it yet.
It is not suggested that a 10.3″ version has been issued, however.
Reference Pics
Here’s a select few pics of the URG-I in the wild. Note how varied the setups are, because this is not a new rifle – it’s an enhancement of an existing one.
All pics are from the AR15.com thread and @btl_ltw
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