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.223 behavior in carbine-length barrels
offeror
Member Posts: 8,625 ✭✭
I thought the following response to a letter to a GUNS & WEAPONS FOR LE magazine column was worth reading since it is about a caliber of interest and its behavior in short barrels:
# # #
"I am a retired FBI agent, writing under (an assumed name) and I conducted the research for the FBI concerning penetration tests on the .223 vs. pistol ammo from an MP5, during which it was determined that on average, .223 in any configuration penetrates less than 9mm, .40 S&W and 10mm.
"When selecting a 5.56 carbine one must keep in mind that this round is very velocity-dependent. This high velocity projectile destroys tissue all out of proportion to its caliber primarily by two mechanisms: the temporary stretch cavity and bullet fragmentation. Unlike pistol rounds that require deep penetration and a permanent wound channel, which destroys tissue by contacting it, this caliber (.223) does not. When the surrounding tissue is stretched after about three inches of penetration, it is synergistically perforated by the bullet's fragments, and is torn, creating severe wounds and trauma.
"To achieve this performance, however, particularly when using military ball ammo, the minimum velocity the round must exit the muzzle is 2500 fps. Barrel length (runway) is critical for effective muzzle velocities. Going below 14.5 inches (Colt MK4 carbine) is not recommended. Micro carbines are generally useless from a terminal ballistics perspective. They are also louder and exhibit more muzzle blast. Full auto versions usually see their cyclic rate increase. However, Giles Stock, former Phoenix police officer and Hornady employee, conducted relatively recent research into the rounds most suitable for ultra short carbines.
"Depending what you want to accomplish with the carbine, patrol/tactical will usually determine a preferred configuration. I would stick with single fire versions, because they are usually cheaper and more controllable. -- Quantico, VA"
(attribution of publication is given above)
# # #
This article suggests to me that the really short-barreled carbines are better off with good pistol rounds. I have often wondered about those shortie .223 uppers and semi-auto "sub-machine pistols" like the banned OA-93 and the Carbon 15, but this fellow makes something like the HK USC, the UZI, even the MACs and Tech 9s seem more useful for barrels shorter than 14". I must admit the .45 caliber versions of these short carbines have appeal to me, but 10mm or even .44 magnum sound interesting too.
-- Life NRA Member
"If dishonorable men shoot unarmed men with army guns, the evil must be prevented by the penitentiary and not by general deprivation of constitutional privilege." - Arkansas Supreme Court, 1878
# # #
"I am a retired FBI agent, writing under (an assumed name) and I conducted the research for the FBI concerning penetration tests on the .223 vs. pistol ammo from an MP5, during which it was determined that on average, .223 in any configuration penetrates less than 9mm, .40 S&W and 10mm.
"When selecting a 5.56 carbine one must keep in mind that this round is very velocity-dependent. This high velocity projectile destroys tissue all out of proportion to its caliber primarily by two mechanisms: the temporary stretch cavity and bullet fragmentation. Unlike pistol rounds that require deep penetration and a permanent wound channel, which destroys tissue by contacting it, this caliber (.223) does not. When the surrounding tissue is stretched after about three inches of penetration, it is synergistically perforated by the bullet's fragments, and is torn, creating severe wounds and trauma.
"To achieve this performance, however, particularly when using military ball ammo, the minimum velocity the round must exit the muzzle is 2500 fps. Barrel length (runway) is critical for effective muzzle velocities. Going below 14.5 inches (Colt MK4 carbine) is not recommended. Micro carbines are generally useless from a terminal ballistics perspective. They are also louder and exhibit more muzzle blast. Full auto versions usually see their cyclic rate increase. However, Giles Stock, former Phoenix police officer and Hornady employee, conducted relatively recent research into the rounds most suitable for ultra short carbines.
"Depending what you want to accomplish with the carbine, patrol/tactical will usually determine a preferred configuration. I would stick with single fire versions, because they are usually cheaper and more controllable. -- Quantico, VA"
(attribution of publication is given above)
# # #
This article suggests to me that the really short-barreled carbines are better off with good pistol rounds. I have often wondered about those shortie .223 uppers and semi-auto "sub-machine pistols" like the banned OA-93 and the Carbon 15, but this fellow makes something like the HK USC, the UZI, even the MACs and Tech 9s seem more useful for barrels shorter than 14". I must admit the .45 caliber versions of these short carbines have appeal to me, but 10mm or even .44 magnum sound interesting too.
-- Life NRA Member
"If dishonorable men shoot unarmed men with army guns, the evil must be prevented by the penitentiary and not by general deprivation of constitutional privilege." - Arkansas Supreme Court, 1878