This page summarizes the weapons seen in Serious Sam: The First Encounter, Serious Sam: The Second Encounter, and their HD remakes.
The following weapons can be seen in the Serious Sam video games:
A fictional revolver very loosely based on the Smith & Wesson Schofield appears as the "Schofield .45 (W/ TMAR)" is the first weapon, alongside the Military Knife, that Sam starts with. It has unlimited ammo (but needs to be reloaded after six rounds have been fired), pin-point accuracy, and can be dual-wielded.
NETRICSA Description: Replica of original 1875 Schofield calvary model, modified for increased accuracy. A solid and reliable weapon, but normally not very efficient for combat situations due to it's low rate of fire. This one is fitted with a small Techno-Magical Ammunition Replenisher (TMAR) captured from Mental's forces, to provide infinite ammunition supply. Useful as a last-resort defence and for elimination of weaker enemies at long-range.
The fictional pump-action shotgun appears to be a hybrid of a Remington 870 Police Magnum and a Mossberg 500 Cruiser (with certain features similar to those of the Fort-500 series of shotguns), including wooden furniture, an extended barrel and tube, and a pistol grip. It is the second weapon Sam gets in both encounters, and shares ammunition with the Coach gun, with the addition of not needing to be reloaded. The ammo capacity is 200.
NETRICSA Description: A single-barreled 12 Gauge pump action shotgun. Efficient for short and middle range elimination of smaller enemies.
Double Barreled Shotgun
The "Coach Gun" is a powerful close range weapon with a 20" barrel (In actuality, the barrels are too long for it to be a coach gun). Sam always fires both barrels at a time. It is one of the few weapons that must be reloaded, most weapons in the game have unrealistically high magazines. The Coach Gun shares ammo with a fictional pump-action shotgun. The ammo cap is 200 shells.
NETRICSA Description: Standard double-barreled 12 Gauge shotgun. Efficient for short-range elimination of medium sized enemies, but scatters the pellets too much to be used for long range shooting.
The "Thompson M1-A2" is slightly modified, yet fictional Tommy Gun, the first automatic weapon available for Sam. Despite the name, it actually looks like an updated M1928, and not an M1A1. Appears with the stock removed and has a 16" barrel. It has been converted to fire 5.56mm rounds, but the game still classifies it as a submachine gun. Shares ammunition with the handheld Minigun.
NETRICSA Description: Originally invented by general Thompson, this submachine gun has survived two world wars, and with recent improvements, it is back on the track. This old-timer was modified to accept 5.56mm ammo to be compatible with other standard infantry weapons, and its universal drum container can be filled from any standard ammo pack.
Yet another weapon converted to use the 5.56mm rounds. The "XM214-A Minigun" is a more advanced variant of the M134 Minigun, although it's name suggests that it is an upgraded version of the experimenta XM214 Minigun, which fires the 5.56 in reality. Deals almost the same damage as the M1-A2, but has a better fire-rate. The ammo cap is 999 rounds, the highest of any weapons.
NETRICSA Description: Evolving from Gatling, through Vulcan and M134, XM214-A is latest news in infantry armament. Self-powered and complete with a built-in magazine and a recoil adapter, this is the most powerful personal weapon available.
"Raptor 16mm Sniper Rifle"
The "Raptor 16mm Sniper Rifle" is a fictional heavily modified Hecker & Koch MSG90 with parts similar in appearance to that of the Colt Monitor converted to bolt-action with a wooden buttstock, pistol grip, and a sound supressor that appears only in the Second Encouter of the 2-part Serious Sam game. When unzoomed, it deals roughly the same amount of damage as the pump-action shotgun, but when zoomed in, it deals 3x that damage, making it a weapon of choice for offing various enemies at long distances.
NETRISCA Description: The RAPTOR Sniper is on of the most powerful long range weapons in the world. The 16mm armor piercing kelvar coated bullets will pass right through most known armor types. It causes instant deatrh to small and mid-sized species.
The Raptor has an automatic excess pressure exhaust mechanism that will lower the exit speed of the bullet when it is not fired from a balanced sniping mode. This provides maximum safety and minimal injuries to the weapons wielder.