WC/SWC bullets have a sharp shoulder, which permit them to crush/cut a caliber size hole.
Ball/RN crushes a small hole and then produces several stellate (star like) tears, emanating from the hole, as the smooth, aerodynamic ogive/shoulder nose profile "stretches" the paper as the bullet passes through, which produces a punctate (puncture wound like) hole.
HP/TC bullets produce a hole in paper that's a combination of WC/SWC and Ball/RN. The flat meplat, with a relatively sharp shoulder, crushes/cuts a hole, which is then "stretched" to full caliber size by the smooth/rounded ogive and shoulder contours. The result is a round hole surrounded by an abrasion ring and small stellate tears.
The effects of these different bullet types observed in paper targets is entirely analogous the the effects on living tissues.
WC bullets are perhaps the most efficient shape for crushing tissue. The diameter of tissue crushed/cut remains the same from start to finish.
RN bullets contact more tissue than SWC/unexpanded HP/TC bullets as they penetrate because the tissue flows against the smooth contours. However RN bullets do not produce substantial tissue damage because soft tissues easily stretch around bullet, causing localized bruising and abrasions. An RN bullet will transfer more energy to tissue at a faster rate than an SWC/unexpanded HP/TC bullet. This is because more tissue comes in contact with the smooth rounded surfaces of the meplat/ogive/shoulder and shank than does happen with SWC/unexpanded HP/TC bullets (explained below). As a result, RN bullets will penetrate LESS than SWC/unexpanded HP/TC bullets of the same caliber, weight and velocity.
SWC/unexpanded HP/TC bullets: the flat meplat radially propels soft tissue out of the path of the ogive/shoulder during the bullet's initial wound path, which is why they actually touch less tissue than RN bullets. As the bullet slows, the meplat propels less and less soft tissue away from the ogive/shoulder -- the soft tissue just stretches around the smooth contours of the ogive/shoulder in the same manner observed on paper targets. Now the weird thing is, SWC/unexpanded HP/TC bullets, although they'll penetrate deeper in soft tissue than an RN bullet of the same caliber/weight and velocity, produce a more severe wound because of the tissue that's crushed by the flat meplat.
Expanded HP bullets present a large diameter, somewhat flat "meplat" as they penetrate tissue. The rounded forward edges of the mushroom skirt allows tissue to stretch and flow around the bullet in a manner similar to RN bullets. As an expanded HP bullet penetrates its velocity slows, and this means more and more tissue is able to stretch around the smooth mushroom skirt, instead of being contacted and crushed. The hole produced by an expanded HP bullet in soft tissue actually tapers in diameter -- the hole gets smaller in diameter as less tissue is crushed and more tissue stretches around the penetrating bullet. Thus the maximium diameter of a bullet hole produced in soft tissue can be up to approximately 60 percent of an HP bullet's expanded diameter, and then steadily decreases in diameter toward the terminus of the wound track.
That's my fifty cents worth. :wink:
_________________
Shawn Dodson
FirearmsTactical.com
<font size=-1>[ This Message was edited by: Shawn Dodson on 2001-09-08 21:32 ]</font>
Ball/RN crushes a small hole and then produces several stellate (star like) tears, emanating from the hole, as the smooth, aerodynamic ogive/shoulder nose profile "stretches" the paper as the bullet passes through, which produces a punctate (puncture wound like) hole.
HP/TC bullets produce a hole in paper that's a combination of WC/SWC and Ball/RN. The flat meplat, with a relatively sharp shoulder, crushes/cuts a hole, which is then "stretched" to full caliber size by the smooth/rounded ogive and shoulder contours. The result is a round hole surrounded by an abrasion ring and small stellate tears.
The effects of these different bullet types observed in paper targets is entirely analogous the the effects on living tissues.
WC bullets are perhaps the most efficient shape for crushing tissue. The diameter of tissue crushed/cut remains the same from start to finish.
RN bullets contact more tissue than SWC/unexpanded HP/TC bullets as they penetrate because the tissue flows against the smooth contours. However RN bullets do not produce substantial tissue damage because soft tissues easily stretch around bullet, causing localized bruising and abrasions. An RN bullet will transfer more energy to tissue at a faster rate than an SWC/unexpanded HP/TC bullet. This is because more tissue comes in contact with the smooth rounded surfaces of the meplat/ogive/shoulder and shank than does happen with SWC/unexpanded HP/TC bullets (explained below). As a result, RN bullets will penetrate LESS than SWC/unexpanded HP/TC bullets of the same caliber, weight and velocity.
SWC/unexpanded HP/TC bullets: the flat meplat radially propels soft tissue out of the path of the ogive/shoulder during the bullet's initial wound path, which is why they actually touch less tissue than RN bullets. As the bullet slows, the meplat propels less and less soft tissue away from the ogive/shoulder -- the soft tissue just stretches around the smooth contours of the ogive/shoulder in the same manner observed on paper targets. Now the weird thing is, SWC/unexpanded HP/TC bullets, although they'll penetrate deeper in soft tissue than an RN bullet of the same caliber/weight and velocity, produce a more severe wound because of the tissue that's crushed by the flat meplat.
Expanded HP bullets present a large diameter, somewhat flat "meplat" as they penetrate tissue. The rounded forward edges of the mushroom skirt allows tissue to stretch and flow around the bullet in a manner similar to RN bullets. As an expanded HP bullet penetrates its velocity slows, and this means more and more tissue is able to stretch around the smooth mushroom skirt, instead of being contacted and crushed. The hole produced by an expanded HP bullet in soft tissue actually tapers in diameter -- the hole gets smaller in diameter as less tissue is crushed and more tissue stretches around the penetrating bullet. Thus the maximium diameter of a bullet hole produced in soft tissue can be up to approximately 60 percent of an HP bullet's expanded diameter, and then steadily decreases in diameter toward the terminus of the wound track.
That's my fifty cents worth. :wink:
_________________
Shawn Dodson
FirearmsTactical.com
<font size=-1>[ This Message was edited by: Shawn Dodson on 2001-09-08 21:32 ]</font>
