Patent Application
20140311373
The field of the invention is slugs for use in cartridges fired from handguns and other firearms.
Various types of slugs are used in ammunition. Slugs are made in a variety of shapes and sizes depending upon their intended use. Common types of slugs may be made from lead, jacketed lead, steel (for armor piercing bullets), paper and wax (blanks), rubber (less lethal), and a variety of other materials. The most commonly used slug is made from lead, which can be toxic if it is left in the environment after being discharged from a firearm. In addition, lead is relatively expensive and, thus, costly to use as slug material in firearms.
A lead slug has a certain amount of kinetic energy when it is propelled from the barrel of firearm. The kinetic energy of a discharged slug will be a function of its mass and it velocity via the well-known formula Kinetic Energy (KE)=½ (mass)(velocity)(velocity). [KE=mV2] Assuming the propellant in a firearm cartridge imparts a certain amount force to a slug, a lead slug, due its weight, will be propelled from a firearm with less velocity than a slug with a smaller mass; however, a smaller mass tends to lessen the kinetic energy in accordance with the formula stated above.
Certain kinds of plastic slugs have been made for training purposes; however, they are not in common use for firearms. Lighter plastic slugs have a tendency to arc when expelled from firearms. The arcing affects the accuracy of the shot. For this reason, users have been hesitant to use plastic slugs for personal protection, hunting, or competition shooting.
Delrin® acetal resin (polyoxymethylene), which may be secured from Dupont, is a material that has characteristics that make it possible to use as a slug in firearm cartridges. It is sold in the form of rods (among other forms) of various diameters. It is represented to have the beneficial advantages of creep resistance, strength, stiffness, hardness, dimensional stability, toughness, fatigue resistance, solvent and fuel resistance, abrasion resistance, low wear, and low friction. See the following web site information: http://www2.dupont.com/Plastics/en_US/Products/Delrin/Delrin.html. Delrin® is much less expensive than lead. At the present time, Delrin® is about 5% of the cost of an equal weight of lead.
It would be desirable to make a slug from a non-toxic, smaller mass material that would provide characteristics and qualities equal to or better than lead or other metals. The use of a lighter weight slug would also lessen the “kick” or jump of the firearm and, thus, render shots more accurate. It would also be beneficial to use a less expensive, lighter weight slug, because the velocity of the slug, at shorter ranges, would be higher than the velocity of a lead slug, provided the slug could be made in a configuration and size that would eliminate arcing at common target distances. It would also be beneficial to use a slug that spreads at its leading edge upon impact with the target so that it is more effective in stopping a moving target and less effective in piercing targets at longer ranges so as to prevent damage to targets at longer ranges. It is further desirable to use a slug that is less expensive than lead and more environmentally friendly than lead.
Delrin® 150E BK 602 slugs are used in firearm cartridges instead of lead or other metallic slugs. The Delrin® slugs are cut from cylindrical 0.452 inch diameter Delrin® rods to a length of about 0.8 inches or 1.2 inches. The leading end of the Delrin® slugs is not altered once cut; both the front and tail ends of the Delrin® slugs are flat. At short ranges, the Delrin® slugs are propelled at higher velocities than lead slugs and have greater kinetic energy. The leading edge of Delrin® slugs flattens upon impact with the target, is more effective in stopping a moving target, and does not significantly arc at 15, 25, 50, and 75 yards. Muzzle jump (“lick”) affecting accuracy was significantly reduced. The cost of the Delrin® slugs described about is about 5% of the cost of lead slugs. Other types and sizes of Delrin® slugs may be used in different caliber firearms. In addition, other types of plastic material may also be used instead of Delrin® brand products. In alternative embodiments, the slugs may be made with metal inserts or in stepped or telescoping-like shapes to change, alter or customize the performance of the slugs.
Various types of plastic and other light weight material were tested and used as slugs 7 in 45 long Colt cartridges 1 fired from a revolver. The tests were made at various target distances. A chronograph was used to determine the speed of the slug 7 at the exit from the firearm and at the target. Standard casings 3, propellants 5, and primers 4 were used in the cartridges 1.
All tests were conducted with one of the following firearms: Ruger® Blackhawk, Ruger® Vaquero, Taurus® Judge, and Taurus® Raging Judge magnum using cartridges having overall lengths of 1.4 inches and 1.76 inches. Other types of firearms and different cartridge lengths may also be used.
The casings 3, propellants 5, and primers 4 were the same for each cartridge shot, namely, a .45 casing, Alliant® Bullseye Smokeless Powder propellant, and large pistol and large rifle magnum primers. Other types of casings 3, propellants 5, and primers 4 may also be used.
Delrin® 150E BK 602 material was purchased in the form of a ½ inch diameter rod. The Delrin® rod was milled to a diameter of 0.452 inches to fit in the casing 3 of the .45 revolver cartridge 1. Delrin® rods may be purchased in specific diameters, so in larger scale uses the Delrin® rods may be purchased with a diameter of 0.452 inches. Other types, styles, and sizes of the Delrin® may also be used, and plastics other than Delrin® brand plastic may also be used. The Delrin® slugs tested were varied at 1 inch, 0.8 inch, and 1.2 inches long. The leading end of the Delrin® slugs was not altered; both the front and tail ends of the Delrin® slugs were flat—i.e., as cut. The preferred length of the Delrin® slugs was 1.2 inches. In addition, other diameter of Delrin may be used for slugs in .44 magnum firearms, 45 caliber firearms, .357 firearms, or other firearms.
The slugs 7 were weighed prior to use by a digital scale; most weight measurements were made on the 0.8 inch length Delrin slugs. The weight of the Delrin slugs was 46 grains and the powder weight averaged approximately 15.6 grains as shown below.
The firearm was held in a Ransom rest and fired by a person. Muzzle displacement (“kick”) was noted on all shots. Chronographs we set at the end of the muzzle and 5, 25, 30, 50 and 75 yards from the muzzle. The distances of the targets from the muzzle of the firearm were varied at 5, 15, 25, 30, 50, and 75 yards. The majority of the bullet speeds were measured at 25 yards from the muzzle.
Comparison shots we made with lead slugs 7 and Delrin®150E BK 602 slugs 7. The comparison lead slugs 7 were standard cowboy loads.
The following speeds were recorded for the 0.8 inch Delrin slug at the following distances from the muzzle, yielding the following Kinetic Energy (KE) calculations:
The 0.8 inch Delrin slug was x-rayed in tissue and the slug can be seen on an X-ray.
The target materials used were paper, 2×6 inch plywood sheets (white pine and yellow pine), adhesive gel, sheetrock, wood (2×4), and a bullet proof vest (level IIIA). All discharged slugs hit the target within 2 inches of the point of aim. The target impact areas and the slugs were observed, including the depth of penetration of the slugs. Other visible effects on slugs were also noted. The slug penetrations described below were noted:
The 0.8 inch Delrin slug did not penetrate the front of the bullet proof vest when shot at 12 paces from the vest; when a 0.8 inch slug was shot at the rear of vest from the same distance, the slug did penetrate the vest somewhat, but the slug did not go through the vest. When a 2½ inch sheetrock sheet was placed inside the vest, the sheetrock received about 0.3 inches of compaction from the slug pressure. The 0.8 inch Delrin slug penetrated two (2) one-half (½) inch plywood sheets and, thereafter, two (2) one half (½) inch sheets of sheetrock sheets at 25 yards. The 0.8 inch Delrin slug penetrated two (2) one-half (½) inch sheets of sheetrock and then one (1) one-half (½) inch sheets of plywood sheet at 25 yards. The 0.8 inch Delrin slug also penetrated six (60 one-half (½) inch of sheetrock at 25 yards, one (1) one-half (½) inch sheets of plywood at 50 yards, and ⅛ inch of plywood at 75 yards.
A chart of some of the pertinent test results is shown below. In each case, the slug weight was 46 grains.
In other tests, a wood (2×4) target was used with a paper target immediately behind the wood target. The 1.2 inch Delrin 150E BK 602 slugs 7 with diameters of 0.452 inches were discharged toward the targets with a .45 long Colt revolver, at 15, 25, and 50 yards. The results of the tests were as follows:
At 15 yards the front side of a wooden target (2×4) had a clean penetration, but widened to approximately 1.5 inches on backside. A paper bulls eye target behind the wooden target had a clean shape/size penetration somewhat resembling the shape of the Delrin® 150E BK 602 slug 7.
At 25 yards the front side of a wooden target (2×4) had a clean penetration, but widened to approximately 3 inches on backside. A paper bulls eye target behind the wooden target had a clean shape/size penetration somewhat resembling the shape/size of the Delrin® slug 7.
At 50 yards the front side of a wooden target (2×4) had a clean penetration, but widened to approximately 5 inches on backside. The paper target behind the wooden target had a clean shape/size penetration, again somewhat resembling the shape/size of the Delrin® slug 7, but producing a hole somewhat larger than the shots at 15 and 25 yards.
The Delrin® slugs did not exhibit any significant arcing or inaccuracy compared to the lead slugs. The depth of penetration of the Delrin® slugs was significantly less than the depth of penetration of the lead slugs. The velocity of the Delrin® slugs was significantly higher than the velocity of the lead slugs. No significant differences in accuracy were noted between the lead and Delrin® slugs 7. The kinetic energy of the Delrin® slugs was significantly higher than that of the lead slugs at the shorter distances.
The Delrin® slugs 7 were deformed on their leading edges after hitting the target, apparently accounting for the shorter penetration distances of the Delrin® slugs. The deformation was “mushroom” shaped. The Delrin® slugs 7 were, otherwise essentially whole after penetration and only slight deformation of the following edge of the Delrin® slugs was noted. No significant fragmentation of the Delrin® slugs 7 was observed.
Due to the lighter weight and higher speed of the Delrin® 150E BK 602 slug, the Delrin® slug 7 exited the gun barrel before there was any significant muzzle jump, as shown in
Several advantages were found to be gained from the use of the Delrin® Slugs 7:
a) The cost of the Delrin® slugs 7 used in the tests was about 5% of the cost of lead slugs, based on weight and then prices current at the time of the tests.
b) The Delrin® slugs 7 did not require any modifications to the leading or trailing edge of the slug once cut.
c) Although the Delrin® slugs 7 used in the tests were milled to 0.452 inches in diameter, Delrin® rods may be ordered in specific diameters, including a 0.452 inch diameter.
d) Muzzle jump (‘kick”) using Delrin® slugs 7 was significantly less than the muzzle jump accompanying the use of lead slugs, increasing the accuracy of the shot.
e) No increased arcing of the Delrin® slugs 7 (as compared to lead slugs) was noted at the distances tested.
f) The “mushroom” shaped deformation of the leading end of the Delrin® slug 7 caused the slug to be stopped more quickly by the target upon impact, making the Delrin® slug 7 safer for enclosed spaces (aircraft and homes, for example) and safer for outdoor spaces where a slug passing through the target could impinge upon unintended objects or people after passing through the target.
g) The Delrin® slugs 7 did not significantly disintegrate or fragment upon impact, making them easier to retrieve from the target and less like to contaminate game when used for hunting.
h) In human combat/protection applications, the Delrin® slug 7, due to its deformation upon impact, appeared more likely to stop an intruder/opponent and less likely to travel through the intruder and endanger other persons or property.
i) The lighter weight of the Delrin® slug 7 allowed it to travel significantly faster to the target; in the tests conducted, the speeds of all of the Delrin® slugs greatly exceeded that of the lead slugs.
j) Due to the increase speeds of the Delrin® slugs 7, and despite the significantly decreased weight of the Delrin® slugs 7, the kinetic energy of the Delrin® slugs 7 was significantly higher than that of the lead slugs at the distances tested.
k) The use of Delrin® slugs 7 would not pollute the environment with lead, as would be the case with lead slugs.
l) Damage to the target was greater when impacted by the Delrin® slug 7 than when impacted by the lead slug; thus, the Delrin® slug 7 would appear to be more effective in stopping a moving target than lead at the distances tested.
It is understood that the same or other types of plastics may be used for slugs in different caliber fire arms, and that the length, diameter, and shape of the slug may vary depending on the type of firearm and cartridge used.
In an alternative embodiment shown in
Although copper was used in the test referenced above, other metals, such as steel or lead, could be used as the insert instead of copper. There are also various ways the metal can be inserted into the Delrin® slug. For example, the metal may be heat softened and placed in the Delrin® slug, extruded into the slug 8, screwed into the slug, inserted with pressure of force, or placed in the slug 8 by other means known in the art.
The depth and diameter of the hole depends on the length and diameter of the Delrin® slug 8, which, in turn depends on the size of the cartridge 1 needed for the firearm from which the slug 8 with the metal insert 11 is to be propelled.
When fired from a firearm, the Delrin® slug 8 with the copper insert 11 carried downrange about 200 yards—farther than the Delrin® slug 7 without the copper insert.
Further in the alternative, the metal insert 11 may extend beyond the leading end of the Delrin slug 8. In such applications the Delrin® slug 8 may be made so that it is dislodged from the metal 11 at the time it exits the barrel of the firearm and, thus, perform in the nature of a Sabot bullet. Such Sabot-like small caliber bullets may then be used in firearms with larger bores.
Further, in applications using a metal insert 11, the extra weight of the bullet due to the metal is believed to render the bullet as “non-armor piercing.”
In another embodiment shown in
In a further embodiment shown in
The slugs 7 (flat end), 12 (each step 0.1 inch high), and 18 (each step 0.2 inches high) were tested by firing from a 500 magnum firearm. The target consisted of 6 inches of cardboard in front of a ¾″ inch piece of plywood, which, in turn was in front of target rubber. The target was 25 yards from the firearm. Speed was measured at 5 yards from the firearm, and kinetic energy was calculated using the speed so determined.
The test results are summarized below:
Upon impact with the target slugs 12 and 18 spread out later than slug 7. In general terms, it appeared that the flatter the forward end of the slug, the less penetration, and the greater the speed, the greater the kinetic energy.
It is understood that, although this application references handguns, the special purpose slugs described could also be made to fit and be used in rifles, as well. In addition, although reference is frequently made to the Delrin® slugs, other type of plastics could also be used.
This application claims priority to U.S. Provisional Application 61/675,607, filed Jul. 25, 2012; U.S. Provisional Application 61/700,688 filed Sep. 13, 2012, and U.S. Provisional Application 61/755,774 filed Jan. 23, 2013, the disclosures of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61675607 | Jul 2012 | US | |
| 61700688 | Sep 2012 | US | |
| 61755774 | Jan 2013 | US |
