Cast Lead vs. FMJ Penetration

keys85 · September 28, 2008, 12:16 AM

I was wondering if hard cast bullets had similar penetration to jacketed rounds (pistol) in soft tissue. I have not run any tests but am curious as to if any of you have.

The hard cast will penetrate deeper than soft lead, and I'd imagine the FMJ round would penetrate a little deeper than hard cast, but considering a FMJ hollow point which will expand much more than a cast lead bullet, would penetration be similar?

T. O'Heir · September 28, 2008, 12:53 AM

"...hard cast bullets had similar penetration to jacketed rounds..." Nope. The jacket's job is to control expansion. A cast bullet, hard or not, will start to deform immediately. Saw the result of an FMJ 9mm and a cast bullet after hitting a Second Chance vest, long ago. The 9mm literally mushroomed and had the imprint of the vest's kevlar layers on it. The cast bullet was just flat.
"...a FMJ hollow point..." No such thing. An HP isn't an FMJ. Jacketed HP's are also designed to have controlled expansion.

keys85 · September 28, 2008, 02:06 AM

Yes, what I meant to say was FMJ versus a jacketed hollow point round. I've seen soft lead flatten to pancakes when shot through four 2/4's, but have not had any experience with hard cast (24 BHN) and do not know if they deform to the extent of soft lead. The FMJ rounds I shot into the 2x4's did not deform much at all, in fact, I recovered one round that had only the rifling marks on it and I reloaded that round just for fun.

The soft lead bullets actually penetrated further than the FMJ in that testing...but a .40 SW and .45 ACP calibers were used, respectfully.

So what I take is that the hard cast lead will deform much more than a FMJ, thus not penetrating as deep. But a jacketed hollow point with controlled expansion will penetrate (if not clogged) 12-14" in gelatin (according to FBI protocols) so I guess what I am asking is, if a hard cast bullet in the same weight and velocity range of a hollow point meets soft tissue, which is more likely to penetrate? Is it possible the hard cast will deform that much as to not give at least 12-14" or because it is not designed to expand, may actually fragment / deform in a way to provide better penetration, or in the case of self defense, over-penetration?

I only ask because dangerous large african game requires heavy, heavy lead rounds to achieve very deep penetration to bring them down. Hunters generally do not load hollow points when hunting these animals but rather cast lead of some sort.

T. O'Heir · September 28, 2008, 03:08 AM

Hi. Nice to know I'm not the only one up.
2x4's don't tell you much about penetration. A .25 ACP FMJ will go right through one at 100 yards. A long wooden box jammed packed with wet newspapers makes a poor man's ballistic gelatin. Ballistic gelatin is very expensive stuff. Played with about 2 feet of dry newspapers and .22 LR's at about 10 feet, long ago. They went in roughly half way and broke up completely.
Anyway, an FMJ will usually punch through most hard objects. Like doors. A cast bullet and a JHP will usually break up with the JHP retaining more weight. (Clogging the HP doesn't really happen. The jacket peels too fast for that to be an issue. JHP's need a fair bit of velocity to open at all.) A hard cast bullet will penetrate more than a soft lead bullet, of course, but will break up and flatten too. The range any bullet is fired at has some to do with it as well. Velocity dropping as the bullet goes. Fragmenting gives less penetration due to the loss of weight. Has to do with inertia.
"...rather cast lead of some sort..." Not any more. Big lead bullets for big beasties was a Black Powder thing. Big, mean, African critters, like Cape Buffalo and Elephants, are shot with heavy solids now. Mind you, the most successful Brit African hunter used an fmj .303 British or 7mm Mauser for a head shot. Lions are shot with big, heavy SP's. The .375 H&H is the minimum cartridge allowed for big, mean game, in most African places.
"...in the case of self defense..." In your house? No handgun round is that great. It takes a very high skill level to fight accurately with a handgun. If you miss with one shot that goes on to cause any kind of damage, way over there, you're responsible. The best tool is a 12 or 20 guage pump, moderately choked, shotgun loaded with large bird shot. Number 2's or BB's. Aimed at the body mass centre, not just pointed. Number 2's or BB's will stop a bad guy, but won't penetrate a solid door or go very far.

September 28, 2008, 12:16 AM	#1
keys85 Junior member Join Date: September 20, 2008 Posts: 199	Cast Lead vs. FMJ Penetration I was wondering if hard cast bullets had similar penetration to jacketed rounds (pistol) in soft tissue. I have not run any tests but am curious as to if any of you have. The hard cast will penetrate deeper than soft lead, and I'd imagine the FMJ round would penetrate a little deeper than hard cast, but considering a FMJ hollow point which will expand much more than a cast lead bullet, would penetration be similar?

September 28, 2008, 12:53 AM	#2
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...hard cast bullets had similar penetration to jacketed rounds..." Nope. The jacket's job is to control expansion. A cast bullet, hard or not, will start to deform immediately. Saw the result of an FMJ 9mm and a cast bullet after hitting a Second Chance vest, long ago. The 9mm literally mushroomed and had the imprint of the vest's kevlar layers on it. The cast bullet was just flat. "...a FMJ hollow point..." No such thing. An HP isn't an FMJ. Jacketed HP's are also designed to have controlled expansion. __________________ Spelling and grammar count!

September 28, 2008, 03:08 AM	#4
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	Hi. Nice to know I'm not the only one up. 2x4's don't tell you much about penetration. A .25 ACP FMJ will go right through one at 100 yards. A long wooden box jammed packed with wet newspapers makes a poor man's ballistic gelatin. Ballistic gelatin is very expensive stuff. Played with about 2 feet of dry newspapers and .22 LR's at about 10 feet, long ago. They went in roughly half way and broke up completely. Anyway, an FMJ will usually punch through most hard objects. Like doors. A cast bullet and a JHP will usually break up with the JHP retaining more weight. (Clogging the HP doesn't really happen. The jacket peels too fast for that to be an issue. JHP's need a fair bit of velocity to open at all.) A hard cast bullet will penetrate more than a soft lead bullet, of course, but will break up and flatten too. The range any bullet is fired at has some to do with it as well. Velocity dropping as the bullet goes. Fragmenting gives less penetration due to the loss of weight. Has to do with inertia. "...rather cast lead of some sort..." Not any more. Big lead bullets for big beasties was a Black Powder thing. Big, mean, African critters, like Cape Buffalo and Elephants, are shot with heavy solids now. Mind you, the most successful Brit African hunter used an fmj .303 British or 7mm Mauser for a head shot. Lions are shot with big, heavy SP's. The .375 H&H is the minimum cartridge allowed for big, mean game, in most African places. "...in the case of self defense..." In your house? No handgun round is that great. It takes a very high skill level to fight accurately with a handgun. If you miss with one shot that goes on to cause any kind of damage, way over there, you're responsible. The best tool is a 12 or 20 guage pump, moderately choked, shotgun loaded with large bird shot. Number 2's or BB's. Aimed at the body mass centre, not just pointed. Number 2's or BB's will stop a bad guy, but won't penetrate a solid door or go very far. __________________ Spelling and grammar count!

September 28, 2008, 02:06 AM	#3
keys85 Junior member Join Date: September 20, 2008 Posts: 199	Yes, what I meant to say was FMJ versus a jacketed hollow point round. I've seen soft lead flatten to pancakes when shot through four 2/4's, but have not had any experience with hard cast (24 BHN) and do not know if they deform to the extent of soft lead. The FMJ rounds I shot into the 2x4's did not deform much at all, in fact, I recovered one round that had only the rifling marks on it and I reloaded that round just for fun. The soft lead bullets actually penetrated further than the FMJ in that testing...but a .40 SW and .45 ACP calibers were used, respectfully. So what I take is that the hard cast lead will deform much more than a FMJ, thus not penetrating as deep. But a jacketed hollow point with controlled expansion will penetrate (if not clogged) 12-14" in gelatin (according to FBI protocols) so I guess what I am asking is, if a hard cast bullet in the same weight and velocity range of a hollow point meets soft tissue, which is more likely to penetrate? Is it possible the hard cast will deform that much as to not give at least 12-14" or because it is not designed to expand, may actually fragment / deform in a way to provide better penetration, or in the case of self defense, over-penetration? I only ask because dangerous large african game requires heavy, heavy lead rounds to achieve very deep penetration to bring them down. Hunters generally do not load hollow points when hunting these animals but rather cast lead of some sort.