Drizzt
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Shotgun experiment came up short
By Don Lewis
Outdoors Columnist
Friday, September 30, 2005
Although the rifle has always been a big game rig, back in the 1920s or early 30s, an attempt was made to make shotguns suitable for big game hunting, at least at close range. Ammunition makers cranked out shotshells using a single round ball of lead. The punkin’ ball shell was loaded to somewhat higher velocities than regular shotshells. The lead ball had the diameter and weight to kill many species of large game-provided it could be placed in the chest area. It was a common round prior to World War II, and hundreds of hunters in the bleak Great Depression era got their deer with the ol’ punkin’ ball.
While it had the kinetic energy to kill a deer or black bear at ranges well under 100 yards, it lacked in the accuracy column, especially at distances beyond 40 yards. However, there is a ballistic reason for the lead ball’s errant flight.
Back then, the shotgun’s bore was a smooth tube. There were no rifling in the bore to make the projectile rotate, although it’s unlikely rotating the ball would have make it more accurate. In contrast, a rifle’s barrel has lands and grooves and as the elongated bullet passes through the bore, the rifling causes it to spin at a very fast rate. When it exits the muzzle, a rifle’s elongated bullet can be rotating several hundred thousand times a minute, The rifling is measured by turns per inch. For example, a one in seven twists means the bullet makes a complete rotation in the bore every seven inches, and that’s a very fast twist. At velocities in the 3,000 feet per second range, the bullet is turning around 300,000 times a minute.
The round (not elongated) punkin’ ball is slightly smaller than the bore and simply passes through it more or less bouncing from side to side. It doesn’t turn like a rifle’s bullet and consequently it is not stabilized. High rotation causes a bullet to be stabilized, and this holds the bullet on a true course.
There have been many new developments regard-ing the shotgun slug. After World War II, the rifle slug was popular. This was an elongated bullet, that had angled fins swaged on it. The fins were supposed to make the slug rotate, but not at sufficient revolutions per minute to stabilize the elongated slug.
Admittedly, the old Foster-type slug and one called the Brenneke were more accurate than the round ball, but not enough to make the shotgun an accurate big game outfit it, especially at long ranges.
Today, there are newer developments. First and foremost is the rifled shotgun barrel. Gun manufacturers are now putting rifling in shotgun barrels that are designed primarily for slug shooting.
Several ammunition makers are producing a new type of elongated bullet generally known as a sabot slug. The new slug carries an hourglass configuration and is surrounded by two plastic halves. The sabot fits tightly in the bore sealing off the hot gases behind it. The sabot also grips the rifling (lands and grooves) forcing the slug to rotate at a high RPM. The old punkin’ ball and rifled slug had little semblance of balance or precision. They were just large hunks of lead. That’s not the case with some of the sabot projectiles. They are held to close tolerances and they are more accurate than their predecessors.
In tests I conducted a few years back using sabot typed shotgun projectiles printed three-shot groups under three inches at 100 yards. The old punkin’ ball and rifled slug were hard pressed to even come close to that measurement at 50 yards. Along with a higher degree of accuracy, the sabot bullet is extending the effective killing range from 75 yards of the old slugs to well over 100 yards. It is claimed that the day is not too far away when the rifled shotgun barrel will shoot two-inch groups at 150 yards.
(Don Lewis is a long time outdoor writer for the Leader Times.)
http://pittsburghlive.com/x/tribune-review/trib/newssummary/s_379516.html
By Don Lewis
Outdoors Columnist
Friday, September 30, 2005
Although the rifle has always been a big game rig, back in the 1920s or early 30s, an attempt was made to make shotguns suitable for big game hunting, at least at close range. Ammunition makers cranked out shotshells using a single round ball of lead. The punkin’ ball shell was loaded to somewhat higher velocities than regular shotshells. The lead ball had the diameter and weight to kill many species of large game-provided it could be placed in the chest area. It was a common round prior to World War II, and hundreds of hunters in the bleak Great Depression era got their deer with the ol’ punkin’ ball.
While it had the kinetic energy to kill a deer or black bear at ranges well under 100 yards, it lacked in the accuracy column, especially at distances beyond 40 yards. However, there is a ballistic reason for the lead ball’s errant flight.
Back then, the shotgun’s bore was a smooth tube. There were no rifling in the bore to make the projectile rotate, although it’s unlikely rotating the ball would have make it more accurate. In contrast, a rifle’s barrel has lands and grooves and as the elongated bullet passes through the bore, the rifling causes it to spin at a very fast rate. When it exits the muzzle, a rifle’s elongated bullet can be rotating several hundred thousand times a minute, The rifling is measured by turns per inch. For example, a one in seven twists means the bullet makes a complete rotation in the bore every seven inches, and that’s a very fast twist. At velocities in the 3,000 feet per second range, the bullet is turning around 300,000 times a minute.
The round (not elongated) punkin’ ball is slightly smaller than the bore and simply passes through it more or less bouncing from side to side. It doesn’t turn like a rifle’s bullet and consequently it is not stabilized. High rotation causes a bullet to be stabilized, and this holds the bullet on a true course.
There have been many new developments regard-ing the shotgun slug. After World War II, the rifle slug was popular. This was an elongated bullet, that had angled fins swaged on it. The fins were supposed to make the slug rotate, but not at sufficient revolutions per minute to stabilize the elongated slug.
Admittedly, the old Foster-type slug and one called the Brenneke were more accurate than the round ball, but not enough to make the shotgun an accurate big game outfit it, especially at long ranges.
Today, there are newer developments. First and foremost is the rifled shotgun barrel. Gun manufacturers are now putting rifling in shotgun barrels that are designed primarily for slug shooting.
Several ammunition makers are producing a new type of elongated bullet generally known as a sabot slug. The new slug carries an hourglass configuration and is surrounded by two plastic halves. The sabot fits tightly in the bore sealing off the hot gases behind it. The sabot also grips the rifling (lands and grooves) forcing the slug to rotate at a high RPM. The old punkin’ ball and rifled slug had little semblance of balance or precision. They were just large hunks of lead. That’s not the case with some of the sabot projectiles. They are held to close tolerances and they are more accurate than their predecessors.
In tests I conducted a few years back using sabot typed shotgun projectiles printed three-shot groups under three inches at 100 yards. The old punkin’ ball and rifled slug were hard pressed to even come close to that measurement at 50 yards. Along with a higher degree of accuracy, the sabot bullet is extending the effective killing range from 75 yards of the old slugs to well over 100 yards. It is claimed that the day is not too far away when the rifled shotgun barrel will shoot two-inch groups at 150 yards.
(Don Lewis is a long time outdoor writer for the Leader Times.)
http://pittsburghlive.com/x/tribune-review/trib/newssummary/s_379516.html
