DSFSLRP is a type of ammunition. Its name stands for: Discarding Sabot, Fin Stabilized, Long Rod Penetrator. This type of ammunition was the main anti-armour projectile used by Bolos through until the Bolo Mark IV was developed Post-Collapse with the Railgun as its main weapon. Even then, railguns fired Long Rod Penetrators developed from the DSFSLRP.
This ammunition uses a sabot, which allows it to have fins while being used in a fairly ordinary gun barrel. When fired, the outer casing (the sabot) peels off to reveal the penetrator. The penetrator is made of a very dense material, such as depleted uranium. The penetrator impacts with so much force that it will melt through armor, and still have so much heat that it will kill the crew and hopefully 'cook off' the ammunition. At impact, it is traveling more than a mile a second.