SMALL ARMS OF THE UNITED STATES ARMED FORCES
M55 Liberator with attached M1708 "Fireburst" 25mm Grenade Launcher
M72 Peacemaker with attached M1709 "Spatha" Chain Bayonet
The US Armed Forces are armed with the most advanced weapons on the planet, and this most definitely applies to their small arms. The US National Guard is generally equipped solely with laser rifles; the Army favours a mix; and the US Marine Corps and US Secret Service are equipped almost completely with plasma weapons.
Laser Weapons
Made by Nemean Industries, the M55 Liberator is the most common energy weapon used in the United States today. Its fire selector, located above the MFC insertion port, can switch between semi-, burst and full-auto firing modes and the gun fires in the cyan spectrum of the visual wavelength, thus having 200% of the firepower of the pre-War AER9. The gun is also sold (without the fire selector) to civilians as the AER21. About 60% of the US Army's combat units use the M55 as their primary small-arm - the gun uses the same ammunition (microfusion cells) as the M72 Peacemaker so this is not as great a logistical hassle as it might seem, and the M55 has benefits (longer range, no recoil) over the M72 in various circumstances.
The M56 Minuteman is a shortened version of the M55 typically assigned to artillerymen, tankers and rear-line troops as a holdout weapon.
Finally the M58 Lightbeam is a common sidearm for squad and platoon leaders in the US Army and US National Guard, and is very common in civilian hands under the brand name of the AEP16.
Plasma Weapons
The M72 Peacemaker, made by General Atomics, is the standard-issue rifle of the United States Marine Corps and is also commonly issued to US Army units. It fires hydrogen-plasma bolts at 5430 degrees Fahrenheit, causing severe third-degree burns with even a grazing hit and nigh-certain death or destruction of a limb on a direct hit, and uses the same fire-selection model as the M55 with semi-, burst and full-auto firing modes available. The US military considers it a weapon primarily to be employed against enemy power armour and light vehicles. The M72 lacks the "molecular destabilisation" effect of earlier plasma weapons, but the greater heat of its shots makes up for this.
The M74 Vindicator is a shortened version of the M72 used by US Army, USAF and USMC pilots as a personal defence weapon; and by Marine tankers and artillerymen for holdout purposes.
The M71 Gunslinger plasma pistol is used commonly by US Army commissioned officers as a sidearm, and by Marine squad and platoon leaders as well as officers.
Plasma weapons are far more heavily restricted than laser weapons on the market; the number of civilians willing to go through the BADTFL paperwork and general hassle to own one is rather small.