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Rifled Slugs

ShootingAgainShootingAgain Member Posts: 46 ✭✭
edited October 2010 in Ask the Experts
What would happen if i shot a rifled slug from a smooth bore barrel?

Comments

  • ShootingAgainShootingAgain Member Posts: 46 ✭✭
    edited November -1
    Hello all

    What type of choke if any is best to use to fire rifled slugs?

    Thanks

    Argus
  • ShootingAgainShootingAgain Member Posts: 46 ✭✭
    edited November -1
    Forgive my shotgun ignorance, but would shooting those out of a home defense type gun (no choke?) make any sense at all?

    I guess I should try it and answer my own question [:D].

    I remember shooting a few as a kid out of an old gun that said "full choke" on the barrel. That seems dangerous to me now, but I know little about shotguns, so... maybe it's not.
  • MossbergboogieMossbergboogie Member Posts: 12,211
    edited November -1
    Can you do it safely,, Yes and in most cases even with as much as full choke.

    Does it make sense inside a house with other occupants to be left unharmed no.
  • ShootingAgainShootingAgain Member Posts: 46 ✭✭
    edited November -1
    Hunting was what I sorta had in mind, like would it be ridiculously inaccurate. I personally don't keep a shotgun loaded with anything for home defense - a little harder than a pistol to keep out of reach but still handy.

    Might have to rethink that though.

    Thanks.
  • iwannausernameiwannausername Member Posts: 7,131
    edited November -1
    The traditional rifled slug is also known as a foster style. The rifling on these does bupkiss to stabilize the slug in flight - the bases are hollow, so they are stabilized like a badmitton birdie.

    Slugs for use in a rifled shotgun barrel are mostly in plastic sabots, the sabot grabs the rifling.

    So yeah, use traditional rifled slugs in a smooth barrel. If you have choke tubes, experiment w/ each tube since one may give a better "group" than the other.
  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    ShootingAgain,

    "...but would shooting those out of a home defense type gun (no choke?) make any sense at all?"

    I've slug hunted since I was a child due to the regulations where I grew up.

    Slug hunting, like any other form of hunting or shooting, takes preparation and practice.

    The first thing you'll find is the variations in the range of dimensions of not only the slugs themselves but the barrels also. I would recommend having a shotgun 'smith measure your barrel at the muzzle or choke to see what your dimension is. Then the testing begins by buying several brands of shells to measure and shoot hopefully. If you don't have a rifled barrel skip the sabot slugs. You want a slug that fits the bore as close as possible without too being tight to move through the bore. If measuring is too hard, cut a shell open, remove the slug and see if it slides down the barrel.

    An example of attainable accuracy:

    shotgunslugsbpaccuracys.jpg

    "SHOTGUNS AND SLUGS are a short-range combination. A look at the ballistics tables in any ammunition catalog will tell you so. Most of them give numbers out to only 125 yards, and for most slugs, even that is stretching it.

    But the situation is changing and changing rapidly. The effective range of shotgun slugs is growing almost by the day. A field that was a ballistic backwater until a decade ago is suddenly one of the most interesting areas of research for a ballistician. Ammunition makers are racing to develop slugs for a high-tech age.

    The reason? Demand, motivated by regulation. More and more jurisdictions are mandating shotgun-only deer seasons.

    "Half of all the deer shot every year are taken with shotguns," says Remington research engineer Vince Scarlata, "and of those, I would say 90 percent are shot with slugs. That is a huge market. And, with the developments we are seeing, shotgun-slug research has become an exciting field."

    All the research in the world, however cannot repeal the laws of physics, and it is those immutable laws that have, for more than a century, made shotgun slugs a 100-yard proposition.

    Shotguns as we know them descended directly from muskets-smoothbores that fired both charges of pellets and single-- round lead balls. These single projectiles, popularly called "pumpkin balls," worked well enough out to about 50 yards. With the arrival of choke-boring, however, even that minimal effectiveness was reduced. With balls made small enough to fit through even the tightest choke, accuracy fell off alarmingly.

    In the 1930s, a shotgunner named Karl M. Foster developed the slug that now bears his name. Cup shaped, with a hollow skirt that would expand to fit the bore, the Foster remained one of the two dominant slug designs for half a century. Winchester began loading them in 1936 and still does. The other design was the European Brenneke, which employed a lead cylinder with a fiber wad attached to the base. Both the Foster and the Brenneke have lead vanes which impart a slight spin for stability, but do little to enhance accuracy.

    The Foster and the Brenneke are effective out to about 100 yards. Beyond that, you run into several problems. The biggest is that you lose accuracy. Right behind that is loss of killing power. And, as the slug sheds velocity, it begins to plunge like a stone. In the search for a slug that is effective out to the unheard of distance of 200 yards, these are still the three obstacles that must be overcome.

    Every engineer in the field agrees that a gun-and-slug combination that is effective beyond 150 yards will have a fully rifled barrel and will shoot sabot slugs. Smoothbores and Foster slugs will never cut it. Let's look at each of these three obstacles individually from a gun and projectile point of view.

    Accuracy

    For deer, you need to be able to keep all your shots in a 6-inch circle at 200 yards.

    The major challenge in this area lies with the ammunition, not with the gun. It is a simple matter to put a rifled barrel on most standard shotguns and attach a scope that allows precision aiming. Put on a 2.5X or 4X scope and you have the accuracy you need.

    A sabot slug then gives you a combination of rotation for stability and a decent ballistic coefficient. Sabots have been around for a couple of centuries. They were first used in muskets. The word is French for the wooden shoes that were common in the 18th century, and were so named because the first sabots came in two parts, each resembling a shoe. The musketeer enclosed his bullet inside the two halves, and pushed the whole thing down the barrel.

    Today's shotgun sabots are made of synthetic material that hugs the rifling, imparting a high rate of spin without exceeding the standard shotgun breech-- pressure limit. When it exits the muzzle, the sabot falls away, leaving the slug rotating like a rifle bullet. Using sabots, shotguns can be made to fire slugs that closely resemble rifle bullets from a .45-70 or similar cartridge. They can be jacketed or have hollow points. Most important, they have a much higher ballistic coefficient than standard slugs.

    Typically, the Foster slug has a coeffident of around .07-so abysmal that most ballistics charts do not give the velocity and trajectory figures for it (.09 is as low as most of them go). The new Remington solid-copper slug has a coefficient of .211, while their newest bonded slug has a coefficient of around .300. Suddenly, we have a projectile capable of both long-range accuracy and velocity retention.

    Killing Power

    With the old slugs, velocity was shed so quickly after 100 yards that penetration suffered. With sabot slugs, most of which weigh about an ounce, the penetration and killing power will be there at 200 yards provided you actually hit the target. Expansion is generally not a consideration as it is with rifle bullets. Even the smaller sabot slugs have such a wide diameter (typically .50 caliber) that they do not depend on expansion to provide punch, although the newer sabot slugs like the Winchester Partition Gold and the bonded Remington do provide expansion capability if there is sufficient retained velocity.

    Remington's solid-copper slug has a muzzle velocity of 1,550 fps and a very respectable energy of 2,334 ft.-lbs. At 100 yards, the energy has dropped to 1,600 ft.-- lbs., and at 200, with velocity down to 1,096 fps, energy is only 1,167 ft.-lbs-just enough killing power for a deer-sized animal.

    Trajectory

    The real problem as velocity drops is the increasingly steep trajectory of the bullet. Between 175 yards and 200 yards, a standard slug may drop 10 inches! This being the case, a range miscalculation of as little as 25 yards can cause a miss even if everything else is right on.

    Fortunately, a great deal of deer hunting today is done from stands. A hunter can use a laser rangefinder to pinpoint the distance to visible objects. When a deer appears, he knows almost to the foot how far he is shooting. Since sabots date from the era of muskets, why not use range stakes, which were also employed by Wellington's infantry?

    Looking at these three areas, it becomes obvious that the best way to extend the range of a slug is to increase the muzzle velocity. With projectiles that better retain velocity, you get more downrange energy and a flatter trajectory. Unfortunately, the governing factor here is pressure. Shotguns are built to withstand maximum-breech pressures of 11,500 psi, whereas a deer cartridge in the .30-06 class will take 50,000 psi.

    The 3-inch 12 gauge works at 14,000 psi. While it has slightly superior ballistics, the longer shell does not offer a great range advantage, nor much potential for improvement.

    "The extra room in the case means you need a bigger wad," says Scarlata. "It does not mean you can stuff in a great deal more powder."

    Engineers working to develop better slug guns must do so within those pressure limitations. Otherwise, what they create may not be a shotgun at all.

    "There is no real definition of a shotgun used by the game departments," says Scarlata, "But a good rule of thumb is that if a firearm uses a cartridge that can be fired from a standard shotgun, then it is a shotgun.

    "When we first introduced the sabot slug, a half-dozen states threatened to disallow it. Their objections were withdrawn when we showed that the slug started to tumble at about 225 yards, which limited the range severely. Our new slugs will not start to tumble until about 275 yards, but that is still close by rifle standards."

    Ammunition companies always have to keep that fact in mind: Shotguns are mandated because they are short-range weapons. Develop a combination that stretches the range too far and you run the risk of having the gun outlawed.

    Given the limitations on the ammunition, 200 yards would seem to be the extreme we should look for in a slug/gun combination, and then only under conditions where ranges can be measured accurately. But consider: Just 10 years ago, 200 yards looked like a pipe dream. Now we are there, and new developments are coming thick and fast."

    Best.
  • wpagewpage Member Posts: 10,201 ✭✭✭
    edited November -1
    If you are going to stick to a certain gun and ammo. Trial is the key. Once you understand it you can succeed.
  • ShootingAgainShootingAgain Member Posts: 46 ✭✭
    edited November -1
    Great info., thanks. I was thinking 100yds would be about the max. I guess I shoulda read the info. on a box of them too, which I just now did [:I]. It says they "...may be fired through any choke;..." The associated graph shows a drop of 4.8" at 100yds if on at 50.
  • blacarrowblacarrow Member Posts: 424 ✭✭✭
    edited November -1
    I was "brain washed" by misinformation about slug shooting, just as most of us were. Then, while working at Browning Arms, I was assigned a project to do the accuracy testing in developing a slug choke for the BPS shotgun.

    To make a very long story short, I shot many many 3 shot groups at 100 yards that were at or under 1", and one that measured 1/2" center to center. I used both foster and sabot ammo, from Winchester, Remington and Federal.

    In the hands of a fairly good shot, deer are "cold meat" at 100 or even more yards when using a good weapon with a good scope.
  • Mark GMark G Member Posts: 1,674 ✭✭✭
    edited November -1
    I tried the same thing many years ago. I had a Mossberg 500 with a folding stock and 18" slug barrel. It had rifle sights and a cylinder bore. One afternoon at the range I decided to see what kind of accuracy I could get from it. Using a 2-3/4" rifled slug at 100 yards, I would get consistent groups between 2" and 3". Since the folding stock didn't have much of a recoil pad, I didn't try the 3" ones. Take it out and see what it will do. Worst thing that can happen is you spend an afternoon shooting.
  • ShootingAgainShootingAgain Member Posts: 46 ✭✭
    edited November -1
    I went out and took one shot each at 25, 50, 100, and 200yds (just for fun). With a fiber optic front sight only, I hit milk jugs at 25 and 50 (woohoo), and a 12-14" diamter gong at 100. I don't know exactly where I hit within those items. I was just happy it did that well.

    I mighta been holding that thing wrong though, because it kicked me under the right cheekbone every time. I don't remember any other guns doing that to me.
  • MossbergboogieMossbergboogie Member Posts: 12,211
    edited November -1
    quote:Originally posted by ShootingAgain
    I went out and took one shot each at 25, 50, 100, and 200yds (just for fun). With a fiber optic front sight only, I hit milk jugs at 25 and 50 (woohoo), and a 12-14" diamter gong at 100. I don't know exactly where I hit within those items. I was just happy it did that well.

    I mighta been holding that thing wrong though, because it kicked me under the right cheekbone every time. I don't remember any other guns doing that to me.


    Shooting off a rest or on a knee is horrid with slugs atleast for me.. I had that same problem, got sick of a sore sholder after only 5 and bought a limbsaver recoil pad... Shot some slugs last weekend with a huge improvement... Keep in mind they make reduced recoil slugs as well.
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