Big Blastas are Da Rogue Boyz machine guns that are bigger than normal Blastas, but slightly harder to carry.
The Big Blasta concept was thought of with creation of Loron crossbows; while many Loron wanted smaller sizes, others wanted larger sizes to smash everything they saw. When Loron simply added fire to crossbows, the Big Arrow Blastas weren't worked on much.
Propa Big Loron Empire
At around the time the Blasta was developed, development from their went in two directions; smaller and bigger. There was more interest in having larger weapons for tougher Loron, and thus, the Big Blastas soon became a popular way of showing off a Loron's strength and toughness, and bravery to carry such a large weapon.
Da Rogue Boyz
When Da Rogue Boyz adopted the Big Blasta designs, the designs were perfected by well renowned mechanics Rel'larutina and Naktor'zak, who both used Propa Big Blastas for their own weapons, and decided from using Propa Big Blastas how to develop the Big Blastas.
The design is variable, but all stats and ammunition are the same. Most look essentially like bits of large machine guns thrown together into a large, 'shooty' weapon. Typical of Loron, they love to paint it, usually to add insignias relevant to their clan or empire etc. They aren't particularly huge for a Loron, although they are too large for most creatures to carry. They are around 1.5m in barrel length.
Used by Loron who want 'more dakka an shooty stuff', the Big Blasta is a large weapon that fires an immense number of bullets at great speed. They are very loud, noisy, and are crude Loron weapons. Loron Gangz contain only one or two Boyz who have one, as they are quite expensive, and the army doesn't currently allow that many to have one.
The bullets use nitroglycerin, and are around 30mm in length. They can be fired at a speed of 1,8000/min, and 600 are contained in a single cartridge. The bullets have a muzzle velocity of 750m/s, with an effective range of 1,600m.
Normally a large spray of autocannon exploding bullets directed at multiple targets. Can be very deadly, although they are unlikely to cause a critical hit. If opponents are unlucky enough to get caught in the fire, they will be wounded quite badly. When a Loron weilder gets close and uses it, the opponent is as good as dead (assuming there's enough ammo in the weapon). The repeating autocannon blasts cause most troopers to be surpressed.
There are no well-known Loron tactics that use Big Blastas.
Loron are best off using this weapon from range and as quickly as possible. The weapons were designed to just spray bullets everywhere. In the army, Loron are best using it at foes who get too close, or at enemies with ranged weapons to force them into cover.