Post by maxman on Nov 5, 2012 3:36:06 GMT
Originally posted by bernieb90, in 2008 on the Mythbusters' Military/Weapons forum.
Every day the message board is filled with questions about the .50 cal. Many fantastic feats have been attributes to this cartridge. From blowing people apart to penetrating bank vaults to blowing skin off with near misses.
The .50 BMG cartridge has been around for almost 90 years. In that time it has seen service in every conflict the United States has been involved in since WWII. Thousands upon thousands of vehicles, structures and people have been shot with the .50.
Prior to the standardization of 10% ballistic gelatin as a test media most terminal ballistics information was based on anecdotal evidence from the battlefield and some live animal testing. Due to the fog of war, battlefield reports must be taken with a grain of salt and soldiers will often exaggerate events. Today we can compare the relative effectiveness of cartridges and predict their terminal performance much more exactly than ever before.
Myth 1: The .50 will rip skin off with a near miss.
Fact: The only way a bullet will ever hurt you is by hitting you. The lack of destructive shockwave is clearly evident when shooting paper targets. The holes in the paper are caliber sized and no additional damage to the target is seen.
tbn0.google.com/images?q=tbn:-VhkUe_PlUjmjM:http...mg/asrul50st100a.JPG
(note clean target holes)
If shockwave effect existed for the .50 it should exist for all other bullets traveling at the same speed. Note that 30-06 and .50 BMG have similar muzzle velocities difference in bullet diameter is less than .2".
tbn0.google.com/images?q=tbn:XwScgrafjAj4EM:http...0408%2520Cheytac.JPG
Myth 2: .50 can blow people apart.
Fact: Although the .50 can cause horrific wounds it can not blow a grown man in half.
Here is picture of the wound channel in gelatin for a .50 BMG .750gr A-Max.
www.brassfetcher.com/images/50blka.jpg
Note maximum diameter of temporary cavity is ~7.5" occurring at a depth of 8". This occurs as the bullet begins to yaw.
Here is a picture of various .308 loads using the Hornady A-Max bullets.
members.aol.com/_ht_a/docgkr/myhomepage/308_TAP_comparison.jpg
Note that temporary cavity diameter is nearly identical, but occurring at a much shallower depth. The .308 A-Max bullets expand and fragment.
Note that the permanent cavity created by the .50 is fairly small early in the wound track. If the .50 passes through a limb without yawing or hitting bone the effect should be similar to a 1/2" icepick wound. However if the round strikes the torso of a thick chested individual it may begin to yaw within the body and produce a large temporary cavity near the end of the wound track. This would result in a massive exit wound and is likely the basis for the myth of people being blown in half.
Myth 3: The .50 can penetrate bank vaults.
Fact: Even .50 AP can only penetrate 1" of rolled armor. As far as concrete goes.
Number of rounds needed to penetrate a reinforced concrete wall at 25° obliquity. Wall Thickness 109 yd (100 m) Range 219 yd (200 m) Range
2 ft (0.6 m) 300 rounds 1,200 rounds
3 ft (0.9 m) 450 rounds 1,800 rounds
4 ft (1.2 m) 600 rounds 2,400 rounds
In other words in order to penetrate a bank vault we need thousands of rounds of ammunition and an alternate method to cut through the re bar.
Also see: democrats.reform.house.gov/features/fifty_caliber/guns_marine_video.rm
Myth: the .50 is magical
Fact: .50 is an excellent tool just like any other.
Every day the message board is filled with questions about the .50 cal. Many fantastic feats have been attributes to this cartridge. From blowing people apart to penetrating bank vaults to blowing skin off with near misses.
The .50 BMG cartridge has been around for almost 90 years. In that time it has seen service in every conflict the United States has been involved in since WWII. Thousands upon thousands of vehicles, structures and people have been shot with the .50.
Prior to the standardization of 10% ballistic gelatin as a test media most terminal ballistics information was based on anecdotal evidence from the battlefield and some live animal testing. Due to the fog of war, battlefield reports must be taken with a grain of salt and soldiers will often exaggerate events. Today we can compare the relative effectiveness of cartridges and predict their terminal performance much more exactly than ever before.
Myth 1: The .50 will rip skin off with a near miss.
Fact: The only way a bullet will ever hurt you is by hitting you. The lack of destructive shockwave is clearly evident when shooting paper targets. The holes in the paper are caliber sized and no additional damage to the target is seen.
tbn0.google.com/images?q=tbn:-VhkUe_PlUjmjM:http...mg/asrul50st100a.JPG
(note clean target holes)
If shockwave effect existed for the .50 it should exist for all other bullets traveling at the same speed. Note that 30-06 and .50 BMG have similar muzzle velocities difference in bullet diameter is less than .2".
tbn0.google.com/images?q=tbn:XwScgrafjAj4EM:http...0408%2520Cheytac.JPG
Myth 2: .50 can blow people apart.
Fact: Although the .50 can cause horrific wounds it can not blow a grown man in half.
Here is picture of the wound channel in gelatin for a .50 BMG .750gr A-Max.
www.brassfetcher.com/images/50blka.jpg
Note maximum diameter of temporary cavity is ~7.5" occurring at a depth of 8". This occurs as the bullet begins to yaw.
Here is a picture of various .308 loads using the Hornady A-Max bullets.
members.aol.com/_ht_a/docgkr/myhomepage/308_TAP_comparison.jpg
Note that temporary cavity diameter is nearly identical, but occurring at a much shallower depth. The .308 A-Max bullets expand and fragment.
Note that the permanent cavity created by the .50 is fairly small early in the wound track. If the .50 passes through a limb without yawing or hitting bone the effect should be similar to a 1/2" icepick wound. However if the round strikes the torso of a thick chested individual it may begin to yaw within the body and produce a large temporary cavity near the end of the wound track. This would result in a massive exit wound and is likely the basis for the myth of people being blown in half.
Myth 3: The .50 can penetrate bank vaults.
Fact: Even .50 AP can only penetrate 1" of rolled armor. As far as concrete goes.
Number of rounds needed to penetrate a reinforced concrete wall at 25° obliquity. Wall Thickness 109 yd (100 m) Range 219 yd (200 m) Range
2 ft (0.6 m) 300 rounds 1,200 rounds
3 ft (0.9 m) 450 rounds 1,800 rounds
4 ft (1.2 m) 600 rounds 2,400 rounds
In other words in order to penetrate a bank vault we need thousands of rounds of ammunition and an alternate method to cut through the re bar.
Also see: democrats.reform.house.gov/features/fifty_caliber/guns_marine_video.rm
Myth: the .50 is magical
Fact: .50 is an excellent tool just like any other.
