16″ SHARPS BROS GOLDEN HOG

The barrel is gold PVD — physical vapour deposition, a hard, thin, well-adhered layer with high wear and corrosion resistance and a low coefficient of friction under pressure. The bolt carrier, the trigger group and the rail fastening screws are titanium nitride, the same family of process. Nothing here is a painted or anodized imitation of gold, and the straight fluting on the barrel cuts weight while holding the H-bar profile’s stiffness.

The Luth-AR Titanium Nitride Trigger Kit (LRPK-THD-TiN) is a conventional Mil-Spec pattern group — trigger, hammer and disconnector, all three TiN coated — fitted on standard Mil-Spec springs. TiN is a hard, low-friction surface treatment: it makes the engagement feel smoother and it resists wear. What it does not do is change the spring rate, so it does not change the pull weight.

Luth-AR publish no figure for the kit, and they do not need to — the springs set the weight, and this rifle runs standard Mil-Spec springs. 5.5 lb is the M4/M16 minimum specification and the band runs to about 8.5 lb. That is a specification rather than a gauged reading of this particular rifle. Ask and we will put a gauge on it before it ships.

The Mil-Spec weight is where it is for safety under stress, and it is the weight the platform was designed around. This is a different arrangement from the SOT WARTHOG rifles, which run a two-stage LaRue MBT-2S with a published 4.5 lb break and a supplied 6 lb spring. Single stage against two stage, Mil-Spec against match — two answers to two different questions, and neither is the upgrade of the other.

Both pull weights above are LaRue’s, obtained by fitting the spring LaRue supply for the purpose. We do not stone, polish or alter sear engagement to chase a lighter break. If a lighter trigger is what you want, the answer is a different trigger, not a modified one.

On the M16 Hybrid Gold TiN group (MAS00103214) only the carrier is TiN gold coated; the bolt, cam pin and gas key are Melonite nitride. MAS also state they use a more cost-effective polishing treatment than their top-tier version. That is worth knowing before you open the rifle expecting a gold bolt — you will find a gold carrier and dark parts inside it, and that is what was bought.

TiN on the 8620 M16-profile carrier gives a 0.45 coefficient of friction, around 2600 Vickers hardness at 2–3 micron thickness, and holds to about 900 °F. Lower friction and less carbon adhesion mean a smoother action and easier cleanup. It is a surface treatment on a Mil-Spec carrier, not a different action — and one of the two places on this rifle where the gold is doing work.

MAS publish the bolt as 9310 or C158 without committing per unit; the group fitted here is the C158 version — heat treated, shot peened and magnetic particle inspected. C158 is the steel specified for the military bolt. Gas key screws are Grade 8, properly staked. There is no hand-staking or OCKS-hardware claim on this group and we are not going to make one.

The 3rd Gen Tactical Humboldt upper is built without an ejection port cover, which leaves the gold carrier visible through the open port. Zoom in on the right-side inspection photograph: the carrier reads gold and the parts around it read dark, which is the hybrid coating described above, visible rather than taken on trust. It also means the action is open to whatever the rifle is carried through.

It is a commercial chamber specification that safely accepts both .223 Remington and 5.56×45mm NATO, cut to give the accuracy of a .223 match chamber without the pressure margin problems of firing 5.56 in one. So the rifle feeds either round, and the CAL MULTI rollmark on the lower is, for once, describing something real.

An oversized billet latch on a 7075-T6 body, matte black hard coat anodized to MIL-A-8625 Type 3 Class 2. The point of the big latch is contact area: it can be worked with gloves on, or with a hand that has to come around a low-mounted optic, without the fingertip pinch a standard Mil-Spec latch asks for.

The Magpul CTR® carries a supplemental friction lock beyond its ambidextrous release latch, clamping the stock to the receiver extension and taking the wobble out of it. Length of pull runs about 10.3″ collapsed to 13.6″ extended, with an integral ambidextrous QD socket, two 1.25″ sling loops, a lanyard hole in the toe and a removable 0.3″ rubber butt-pad. Mil-Spec receiver extensions only. The MBUS® 3 front sight sits on the handguard rather than a gas block because Magpul specify it that way, on account of the heat; the Guntec handguard’s monolithic top rail is what makes that possible here.