It comes down to a few things. Take note of the difference in armament, crew positions and amount of infantry capable of being carried on board.
BMP-1
<Note: I do not suggest this version to be utilized as it's based more upon the Anti-Vehicular role and less suited for Anti-Infantry.>
Armed with a main 73mm rocket cannon, 7.62mm PKT coaxial machinegun and a external AT-3 SAGGER ATGM (Anti-Tank Guided Missle, controlled by wire.) mounted directly above and parallel to the main cannon.
Ammo load-out: 40 x 73mm, 2000 x 7.62mm, 4 x SAGGER.
Ammo Types: 73mm HEAT-FS (HEAT, Fin-Stablized, Rocket Assisted), 73mm HE-Frag (High Explosive, Fragmentation, Rocket Assisted.)
Stabilized Gun - No.
The main 73mm rocket cannon has a maximum potential fire rate of 10 rounds per minute, basically 1 shot per 6 seconds. The main rocket cannon of the BMP-1 is strange as it fires the same ammunition as the RPG-7 infantry rocket propelled grenade launcher.
The AT-3 SAGGER ATGM is mounted above the main cannon and can be fired from the inside of the vehicle. The BMP-1 must remain stationary while firing and guiding the missle. However this missle is not as potent as the superior AT-4 SPIGOT ATGM.
BMP-1P
<Note: I do not suggest this version to be utilized as it's based more upon the Anti-Vehicular role and less suited for Anti-Infantry.>
Armed with a main 73mm rocket cannon, 7.62mm PKT coaxial machinegun and a external AT-4 SPIGOT ATGM (Anti-Tank Guided Missle, controlled by wire.) which is mounted ontop of the turret.
Ammo load-out: 40 x 73mm, 2000 x 7.62mm, 4 x SPIGOT.
Ammo Types: 73mm HEAT-FS (HEAT, Fin-Stablized, Rocket Assisted), 73mm HE-Frag (High Explosive, Fragmentation, Rocket Assisted.)
Stabilized Gun - No.
The main 73mm rocket cannon has a maximum potential fire rate of 10 rounds per minute, basically 1 shot per 6 seconds. The main rocket cannon of the BMP-1 is strange as it fires the same ammunition as the RPG-7 infantry rocket propelled grenade launcher.
The AT-4 SPIGOT ATGM is mounted above the turret and a crewman must fire the ATGM from outside the vehicle. This makes him vulnerable to small arms fire. The BMP-1 must remain stationary while firing and guiding the missle.
BMP-2
<Note: I suggest this version to be utilized as it's balanced between Anti-Vehicular and an Anti-Infantry role.>
Armed with a main 30mm automatic cannon, 7.62mm PKT coaxial machinegun and a external AT-4 SPIGOT ATGM (Anti-Tank Guided Missle, controlled by wire.) which is mounted ontop of the turret.
Ammo load-out: 500 x 30mm, 2000 x 7.62, 4 x SPIGOT.
Ammo Types: 30mm AP and AP-T (Armor Piercing and Armor Piercing, Tracer), HE and HE-T (High Explosive Fragmentation and High Explosive Fragmentation, Tracer.)
Stabilized Gun - Yes.
The main 30mm automatic cannon has a maximum cyclic fire rate of 550 rounds per minute. However burst firing within a range of 200-300 rounds per minute is most practical.
The AT-4 SPIGOT ATGM is mounted above the turret and can be fired from the inside of the vehicle. The BMP-2 must remain stationary while firing and guiding the missle.
