# US 2014/0190364 A1 · Projectile assembly with stabilization/obturation enhancement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190364 A1 - Document ID: US20140190364A1 - Status: Published application - Kind: A1 - Application number: 13/738,646 - Filed: 2013-01-10 - Published: 2014-07-10 - Earliest claimed: 2013-01-10 - Assignees: Alliant Techsystems Inc. - Applicants: Alliant Techsystems Inc. - Inventors: Bryan P. Peterson; Erik K. Carlson; Adam J. Moser; Lawrence P. Head - Web page: https://patentgrep.com/patent/US20140190364A1 ## CPC - F42B 14/064: {Sabots enclosing the rear end of a kinetic energy projectile, i.e. having a closed disk shaped obturator base and petals extending forward from said base} - F42B 5/02: Cartridges, i.e. cases with charge and missile - F42B 7/08: Wads, {i.e. projectile or shot carrying devices,} therefor - F42B 7/10: Ball or slug shotgun cartridges - F42B 14/06: Sub-calibre projectiles having sabots; Sabots therefor - F42B: EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION (explosive compositions C06B; fuzes F42C; blasting F42D) ## Abstract 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. ## Claims ### Claim 1 A projectile assembly for conveying a projectile through a firearm barrel, the projectile assembly comprising: a sabot and a pusher plate, the sabot 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 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 the 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 positioned at the rear surface of the base portion, the disc portion having a periphery; and 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 extending into the projectile seating base of the sabot. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 1) The projectile assembly of claim 1, wherein the sabot is formed of a polymer and the pusher plate is formed of a material selected from a group consisting of metal and a polymer more rigid than the polymer of the sabot. ### Claim 4 (depends on 1) 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. ### Claim 5 (depends on 4) The projectile assembly of claim 4 wherein the pusher plate is comprised of aluminum and the disc portion and the single post are unitary. ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 6) 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. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 1) 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. ### Claim 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 in the casing forward of the wadding, the sabot having a rear end with a rear surface, and a central longitudinal axis, a pusher plate comprising a rigid disc and a central projection extending from the disc forwardly into the rear end of the sabot, a portion of the pusher plate engaging the sabot; and a projectile positioned in the sabot. ### Claim 11 (depends on 10) 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. ### Claim 12 (depends on 11) 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. ### Claim 13 (depends on 10) 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. ### Claim 14 (depends on 10) The projectile assembly of claim 10, wherein the sabot is formed of polyethylene and the pusher plate is formed of aluminum. ### Claim 15 A projectile assembly for conveying a projectile through a firearm barrel, the projectile assembly comprising: a sabot having a 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, whereby upon firing a propellent rearwardly of the projectile assembly in the firearm barrel, the pusher plate and forwardly extending projection facilitate uniform axial deformation of the cylindrical polymer base portion upon compression due to propellant ignition. ### Claim 16 (depends on 15) 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. ### Claim 17 (depends on 15) 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. ### Claim 18 (depends on 15) The projectile assembly of claim 15 wherein the pusher plate is T-shaped in a cross section taken in an axial plane. ### Claim 19 (depends on 15) The projectile assembly of claim 15, wherein the sabot is formed of a polyethylene and the pusher plate is formed of aluminum. ### Claim 20 (depends on 15) 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.