After 24 years of shooting ARs, and countless rebuilds, versions and modifications, I have finally got the first of my Ultimate Builds finished.
This one is a "transitional" model; it incorporates older features like a fixed front sight tower, with newer innovations like a free-float handguard. The inspiration for it is the Diemaco "SFW", which was selected by the SAS after extensive worldwide trials against all the usual suspects. The SFW is an improved varient of the general-purpose infantry rifle, meant for the challenging missions SF operators are tasked with; this UB mirrors these design considerations. I did not want to make an exact SFW clone however, as even it can be improved.
The SAS liked the M-4, but wanted a longer, heavier barrel; Diemaco designed a 16" barrel, which has an unusual profile: heavy under the handguards, and light in front of the gas block; over the light section of the barrel is a steel sleeve meant to support a grenade launcher attachment. For my UB I selected Denny's 16" "Operator" barrel, which is better than the SFW barrel because it has a midlength gas system. The Operator is a "midweight" barrel; slightly lighter than the SOCOM M-4A1 barrel. While this is not a FA rifle, for this UB I followed the SAS logic; I wanted a barrel that could put out a lot of fire without split groups and have a longer effective range than the 14.5" M-4 barrel.
The SAS also chose an improved KAC RAS, but I wanted the benefits free-floating, so I chose the DD Lite 9.0 rail. I have other brands of FF handguards that will be part of my future UBs, but I felt this model was a good fit for this UB, due to it's light weight and good design.
Flash hider is the YHM Phantom with 5 equidistant slots, as I did not want to time it, and have a suspicion that symmetrical slots = better flash hiding potential.
For the Optic I chose the ACOG TA-31, which the Brits will also be using. This optic gives good results for the full effective range of the 5.56 cartridge: from close ranges out to 600m. A proven, rugged design. I chose the LaRue ACOG mount to go with it, since they are superior to the military issue, or the ARMS mounts I have had.
Stock is the MagPul CRT, for strength and simplicity.
BUIS is the Troy folding Battle Sight, as it is the only one the Marines couldn't break.
Pistol grip is the TangoDown Battlegrip, which fits my hand well.
Vertical foregrip is the Tangodown model, which I find stronger than the KAC and cooler than the aluminum types.
Rail covers are the Ladder type, which I think are all made by the same company; I chose them because they are the slimmest.
All plastic is in Flat Dark Earth, as it is a good compromise color. I did not paint the rifle because I've tried the major brands, and did not think they were very durable.
******
That is my first Ultimate build. If you have created your own equivalent, and have a reason for every part on it, I'd like to see it, and hear why you chose your particular components.