Terminal ballistics explained: velocity, expansion and wound mechanisms

Key points: Terminal ballistics explained velocity

• The Discreet Ballistics comparison is not like for like: the 6.5 Creedmoor was a 135-grain A-Tip match bullet at 165 yards, the .300 Blackout a 188-grain terminal hollow point at 75 yards.
• Match bullets wound with velocity alone, while terminal bullets are built to add mechanisms on top, so construction matters more than a muzzle energy figure.
• The temporary cavity only matters above a debated rifle velocity threshold, quoted at 2,000 to 2,700 fps; for handgun rounds it is a gel-block side effect.
• Gel tests at 10 to 15 feet overstate what a rifle round does at 100 or 200 yards, and bone, fat, organ elasticity and body size change the result further.
• Hollow points behave differently in tissue than in gel: tissue stacks in front of the bullet, so it penetrates less but leaves a larger permanent cavity.
• Tumbling rounds widen the wound less predictably, and fragmenting rounds spread damage across the chest to raise the odds of reaching a vital organ.
• Every mechanism has a velocity threshold, so the host's advice is to pick a round by the working range, velocity and caliber you need.

About this Ballistics Focu video

Terminal ballistics explainer from Boondock Ballistician, prompted by a Discreet Ballistics post comparing a 6.5 Creedmoor heart shot with a 188-grain .300 Blackout Selous hollow point. The argument: muzzle energy and velocity are not the whole story, and projectile construction decides how a round dumps its energy. Covers tail splash, the limits of the temporary cavity, blood-pressure shock, and how expanding, tumbling and fragmenting bullets extend the working range where velocity runs out.

Transcript: Terminal ballistics explained