What's wrong in this picture?

[Shawn Dodson]

It appears the poorly informed folks at Fort Scott Munitions believe that skin presents as much as 4-inches of resistance to bullet penetration at entry.

I've encountered this claim before but never from an ammunition manufacturer.

Let's correct the record.

The apparent origin of this misinformation comes from a letter to the editor from Fackler that was published in the March 1987 issue of International Defense Review (pp. 369-370). Fackler wrote:

"Fear of a bullet passing through the body of its intended target and then continuing on to damage a bystander has caused some law enforcement agencies to adopt the lighter bullets because of their shallower penetration, not realizing how seriously this choice compromises weapon effectiveness.

"Forensic pathologists find far too many bullets just under the skin at the point of expected exit to be explained by chance alone. This led us to investigate the role of skin in limiting 'over-penetration' of the expanded pistol bullet.

"We determined the penetration depth of the .45 ACP 200-grain (13g) CCI hollow-point bullet to be 27cm. We then cut a gelatin block at 17cm and held a piece of fresh swine cadaver skin against the back of this block by means of a suitable wooden frame. The same bullets fired through the shortened block did not pass through the skin. These bullets, all of which had expanded to a diameter of 19-21cm, would have penetrated 10cm further had the skin not been there.

"More data is being accumulated using other calibres, but this preliminary study indicates that for a well expanded .45 calibre pistol bullet the skin poses a barrier equivalent to at least 10cm of soft-tissue penetration. It is hoped that knowledge of this added safety factor in preventing body perforation and danger to others will aid in a more rational choice of bullets, i.e., ones that are heavy enough and penetrate deeply enough to be effective in protecting their users."

Fackler, in his letter, was reporting that he and his team of researchers had discovered that unshored skin at the expected point of EXIT from the body can present as much as 4-inches of penetration resistance.

Unfortunately, those with a shallow understanding of wound ballistics, and those who don't practice due diligence in tracking down the origin of information, make false and inaccurate claims, just as Fort Scott Munitions has done in its marketing literature to peddle its "Tumble Upon Impact" bullets.

To further eliminate any misunderstanding, Chapter 9 (pp. 221-243) of Duncan MacPherson's 1994 book, "Bullet Penetration," addresses the effect of skin on bullet penetration. When a bullet impacts and enters the body, he summarizes, "The effect of skin on bullet penetration at ordinary handgun velocities is negligible."

[Jim Watson]

I read a hunter to say that when he could see the down range side of an animal being shot, the hide "tenting" from the impact was obvious and the bullet would be found under the skin.
So I see it as the skin's strength and elasticity being greater than the bullet's penetrating power near the end of its travel. Not happening on entry where the bullet is at full velocity, undeformed, and the skin supported by flesh and bone.

[41magfan]

I read a hunter to say that when he could see the down range side of an animal being shot, the hide "tenting" from the impact was obvious and the bullet would be found under the skin.
So I see it as the skin's strength and elasticity being greater than the bullet's penetrating power near the end of its travel. Not happening on entry where the bullet is at full velocity, undeformed, and the skin supported by flesh and bone.

I've observed this phenomenon (first hand) on deer kills with both rifle and pistol cartridges using expanding bullets. It's as common as dirt and speaks to the elasticity of animal hide when bullet energy drops below a certain threshold.

[cosermann]

Shoot a pellet gun into a hanging bedsheet and it stops the pellet.

Put the bedsheet over a cardboard backer and it penetrates.

The unsupported nature of the skin on the exit side (backside) is key. Seems intuitively obvious.

[358156hp]

It's pretty common to find expanded hunting bullets under the hide on the far side of the animal. Expansion helps increase tissue damage at the cost of penetration.

[willie]

A Vietnam era urologist told me that bullets would not sever ureters, but shrapnel would. To test this, he and his peers suspended and shot string. Bullets did not cut the string. I performed the same test and agree that bullets don't cut string. Bullets knock string aside. Elasticity may not apply here but the thread reminded me of my friend who treated wounded GI's.

[JAH 3rd]

When I read the title of this thread, I was expecting a pic of an HK magazine loaded bullet end first.

[TiroFijo]

Excellent remarks, Shawn.

Could you expect a little different behaviour on the exit side depending on the expanding diameter/mass/shape of the bullet? The "flying ashtrays" expand to close to 0.75" with no sharp protrunding points and probably this exarcebates the "tenting".