Projectile assembly with stabilization/obturation enhancement
View Patent ↗A projectile assembly comprises a base portion for receiving projectiles such as slugs and has an associated pusher plate at a rear end thereof for minimizing or controlling deformation of the rear end of the base portion during firing. The pusher plate has a disc with one or more axially extending projections that extend axially into the rearward end of the base portion thereby reinforcing the base portion and upon firing providing uniform axial deformation and/or obturation of the base portion with respect to a firearm barrel. The projectile assembly may be, for example, part of a shotgun shell slug cartridge, and provides enhanced accuracy over the prior art.
1. A projectile assembly for conveying a projectile through a firearm barrel, the projectile assembly comprising:
a sabot, a single slug sized for the sabot, and a pusher plate,
the sabot formed of a polymer and having a central longitudinal axis, a forward end, a rearward end and a generally cylindrical outer surface, the sabot comprising:
a projectile seating base with a rear surface at the rear end of the sabot and a forward projectile seating surface opposite the rear surface;
a plurality of wings unitary with and extending forwardly from the projectile seating base and positioned circumferentially around the forward projectile seating surface, the forward projectile seating surface and wings defining a cup for receiving a projectile, the wings openable outwardly for releasing the projectile after the sabot and projectile leave the firearm barrel;
the pusher plate comprising:
a disc portion positionable at the rear surface of the projectile seating base, the disc portion having a periphery;
at least one projection extending from the disc portion axially forward, the at least one projection displaced from the periphery of the disc, the disc portion abutting against the rear surface of the sabot and the projection extendable into the projectile seating base of the sabot, wherein the pusher plate is formed of a material more rigid than polymer of the sabot and is configured to not obturate the firearm barrel.
2. The projectile assembly of claim 1 , wherein the disc portion of the pusher plate is circular shaped and wherein the at least one projection is a central axial projection.
3. The projectile assembly of claim 1 , wherein the pusher plate is formed of metal and the disk portion is 0.015 to 0.200 inches thick.
4. The projectile assembly of claim 1 , wherein the at least one projection of the pusher plate comprises a single post extending axially into the projectile seating base of the sabot along the central longitudinal axis of the sabot.
5. The projectile assembly of claim 4 wherein the pusher plate is comprised of aluminum and the disc portion and the single post are unitary.
6. The projectile assembly of claim 1 , further comprising a projectile seated in the sabot and in combination with a shotgun shell cartridge, propellant and wadding.
7. The projectile assembly of claim 6 , whereby when fired in a firearm, the disc portion and forwardly extending projection facilitate uniform axial deformation of the projectile seating base upon compression due to propellant ignition.
8. The projectile assembly of claim 1 , wherein the size of the disc portion conforms to the rear surface of the sabot to cover substantially the entire rear surface.
9. The projectile assembly of claim 1 , wherein the projectile seating base has an axial length and the projection extends into the projectile seating base a distance of at least 20% of the axial length.
10. A projectile assembly comprising:
a casing with a rearward primer end and a forward end;
a propellant in the casing adjacent the primer end;
a primer in the primer end of the casing for igniting the propellant charge;
wadding positioned adjacent the propellant;
a sabot formed of a polymer in the casing forward of the wadding, the sabot comprising a deformable cylindrical portion unitary with a plurality of forwardly extending wings, the sabot having a rear end with a rear surface, and a central longitudinal axis,
a pusher plate comprising a non-obturating rigid disc and a central projection extending from the disc forwardly into the deformable cylindrical portion at the rear end of the sabot, the pusher plate formed of a material more rigid than the polymer of the sabot, a portion of the pusher plate engaging the sabot; and
a projectile positioned in the sabot seated on the projectile seating base.
11. The projectile assembly of claim 10 , wherein the rear surface of the sabot has a tapered recess and wherein the rigid disc is engaged with the rear surface of the sabot and the central projection extends into the tapered recess.
12. The projectile assembly of claim 11 wherein rigid disc has a circular periphery and the projection is rod shaped and unitary with the rigid disc.
13. The projectile assembly of claim 10 , wherein the sabot has a forward facing projectile seating surface, and there is an axial length between the forward facing projectile seating surface and the rear surface of the sabot, and wherein the projection extends into the sabot a distance of at least 20% of said axial length.
14. The projectile assembly of claim 10 , wherein the sabot is formed of polyethylene and the pusher plate is formed of aluminum.
15. A projectile assembly for conveying a projectile through a firearm barrel, the projectile assembly comprising:
a sabot having a deformable cylindrical polymer base portion positioned rearwardly of the projectile, the cylindrical polymer base portion having a forward end for facing the projectile, a rearward end for facing toward propellant, a central axis and a length;
a pusher plate in engagement with the rearward end of the cylindrical polymer base portion, the pusher plate having a disc portion with a periphery and a forwardly extending projection with a tip end extending from the disc portion along the central axis of the cylindrical polymer base portion into the cylindrical polymer base, the pusher plate formed of a material more rigid than the cylindrical polymer base portion whereby upon firing a propellent rearwardly of the projectile assembly in the firearm barrel, the cylindrical polymer base portion is compressed axially and deforms, and the pusher plate and forwardly extending projection facilitate uniform axial deformation of the cylindrical polymer base portion upon the compression due to the propellant ignition.
16. The projectile assembly of claim 15 wherein the pusher plate further comprises a projection extending axially therefrom and wherein the projection is positioned in an axially extending preformed recess at the rear end of the cylindrical polymer base portion.
17. The projectile assembly of claim 15 wherein the cylindrical polymer base portion is sized such that the deformation of the cylindrical polymer base portion provides obturation of the firearm barrel as the cylindrical polymer base portion and projectile travel down the barrel.
18. The projectile assembly of claim 15 wherein the pusher plate is T-shaped in a cross section taken in an axial plane.
19. The projectile assembly of claim 15 , wherein the sabot is formed of a polyethylene and the pusher plate is formed of aluminum.
20. The projectile assembly of claim 15 , wherein the sabot has a forward facing projectile seating surface, and there is an axial length between the forward facing projectile seating surface and the rear surface of the cylindrical polymer base portion, and wherein the projection extends into the cylindrical polymer base portion a distance of at least 20% of said axial length.