He said the Ranger branded bullets used were designed to "expand and mushroom" and cause substantial damage.
Source: Sky News – Pistorius Throws Up During 'Graphic' Evidence
I think it means that it means bullet was in a way that would go fast in the body. Am I right?
Best Answer
Basically, some ammunition is designed so that it deforms throughout impact, rather than retaining its point and passing cleanly through. This is actually designed to make the bullet go slow in the body, stopping sooner (imparting more energy at once) and harmfully widening the impact channel.
This is the sense intended: