In use the EZ model was inaccurate, unreliable, and often dangerous to the user. But it succeeded admirably because it fulfilled its purpose. It retained the basic silhouette of the M16 rifle and lent an air of authority to any force armed with it; the militia looked less rag-tag when it was not armed with deer rifles. It used standard military ammunition and magazines, which helped resupply situations. During the cold days of World War III, it was the rifle that the average citizen saw in the hands of the local militia; it represented a calming voice of authority in the midst of hard times.
‒ Loren Wiseman, Small Arms Guide
One of my favourite game settings is Twilight: 2000. Back in the days, we played both Twilight: 2000, First Edition and Twilight: 2000, Second Edition, although I soon switched to GURPS as a rule system. The Small Arms Guide introduced the M16EZ, a government-issued kit to assemble a militia rifle from second-hand parts and scrounged materials, banged together by a local mechanic.
MilGov M16EZ, 5.56×45mm (USA, 1999-)
MilGov supplied a second-hand barrel, bolt, bolt carrier, and trigger mechanism of an M16 or M16A1 (GURPS High-Tech, p. 117), as well as some basic materials and plans to assemble the rifle. Non-essential parts, especially the furnishing, had to be sourced locally. Consequently, many assembled M16EZ rifles featured wooden stocks.
The M16EZ shown also lacks iron sights. Instead, it has been fitted with an English-made 0.9-lb. United Scientific Instruments L9A1 Sight Unit Small Arms, Trilux (SUSAT) 4× telescopic sight with tritium-powered illumination (+2 Acc, removes -2 from darkness penalties). The sight was primarily used on the British Enfield L85A1 Individual Weapon (IW) assault rifle (High-Tech, p. 118), which might indicate that its last owner was deployed to the European Theatre of War before he returned to the USA.
Most M16EZ rifles were inaccurate and unreliable on account of using well-worn parts and dubious assembly skills. What is worse, most were not capable of employing contemporary military-issue ammunition, which fired heavier bullets and required a different twist of the barrel rifling. The Field Manual 3-22.9 Rifle Marksmanship on the M16-family states that “This ammunition [5.56×45mm NATO M855] should not be used in the M16A1 except under emergency conditions, and only at targets less than 90 meters [100 yards] in distance. (The twist of the M16A1 rifling is not sufficient to stabilize the heavier projectile of the round).”
In game terms, the M16EZ achieves its already mediocre performance only with old 5.56×45mm ammunition of the M193 series. If used with modern 5.56×45mm NATO ammunition of the M855 series, Acc drops to 3 and Range to 300/2,500.
See pp. B268-271 for an explanation of the statistics.
GUNS (RIFLE) (DX-4 or most other Guns at ‑2)
|7||MilGov M16EZ, 5.56×45mm||5d pi||4||500/3,200||8/0.7||13||20/30+1(3)||8†||-5||2||$350/$34||2|||
 Unreliable. Malfunctions on 16+ (p. B407).