Abstract: A retrofit mining haul truck includes a hybrid hydrogen fuel cell/battery-based powerplant in place of a carbon fuel-based powerplant. The retrofit mining haul truck includes a frame, a tray coupled to the frame, and a deck coupled to the frame forward of at least a portion of the tray. A battery system is mounted to the deck of the retrofit mining haul truck. A hydrogen storage system (HSS) is installed in an engine bay volume of the retrofit mining haul truck. The engine bay was configured to contain a combustion engine (e.g., a diesel engine) prior to retrofitting the retrofit mining haul truck. At least a portion of a fuel cell system is installed in a wheel pocket of the retrofit mining haul truck. The wheel pocket was configured to contain a diesel tank prior to retrofitting the retrofit mining haul truck.

Abstract: The present disclosure provides a mining haul truck with the diesel-powered components removed, the resulting available volumes retrofitted with components of a hybrid hydrogen fuel cell/battery-based powerplant. In some embodiments, the tray and/or the canopy of the haul truck can be replaced or reconfigured to create an additional volume for receiving components of the hybrid hydrogen fuel cell/battery-based powerplant.

Abstract: A firearm barrel and a method for manufacturing the same are disclosed. In some embodiments, a barrel for a firearm may be provided. The barrel may comprise a chamber, an entire geometry of which is formed to a final depth. After providing the barrel with the entire geometry of the chamber being formed to the final depth, a material modification process that modifies one or more properties of the barrel may be performed. After performing the material modification process, a composite matrix wrapping that surrounds an outer circumference of the barrel over a length of the barrel may be applied.

Abstract: A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end a nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a pilot band section formed on the projectile body forward of the driving band section. The nose section can be formed having an LD-Haack profile.

Abstract: A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a driving band lead-off section formed on the projectile body adjacent to the driving band section on a rearward side thereof and having an angled surface, with respect to a horizontal axis of the projectile body, that forms a transition from the driving band section to a portion of the projectile body adjacent to the driving band lead-off section on a rearward side thereof. The driving band lead-off section can be formed having an LD-Haack profile.

Abstract: A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a driving band lead-off section formed on the projectile body adjacent to the driving band section on a rearward side thereof and having an angled surface, with respect to a horizontal axis of the projectile body, that forms a transition from the driving band section to a portion of the projectile body adjacent to the driving band lead-off section on a rearward side thereof. The driving band lead-off section can be formed having an LD-Haack profile.

Abstract: A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a driving band lead-on section formed on the projectile body adjacent to the driving band section on a forward side thereof and having an angled surface, with respect to a horizontal axis of the projectile body, that forms a transition from the driving band section to a portion of the projectile body adjacent to the driving band lead-on section on a forward side thereof. The driving band lead-on section can be formed having an LD-Haack profile.

Abstract: A projectile for use with a firearm having a rifled barrel including helical grooves extending longitudinally along an inner surface thereof can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a pilot band section formed on the projectile body forward of the driving band section. The pilot band section can be formed having an LD-Haack profile.

Abstract: A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a driving band lead-off section formed on the projectile body adjacent to the driving band section on a rearward side thereof and having an angled surface, with respect to a horizontal axis of the projectile body, that forms a transition from the driving band section to a portion of the projectile body adjacent to the driving band lead-off section on a rearward side thereof. The driving band lead-off section can be formed having an LD-Haack profile.

Abstract: A projectile for use with a firearm having a rifled barrel can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a driving band lead-on section formed on the projectile body adjacent to the driving band section on a forward side thereof and having an angled surface, with respect to a horizontal axis of the projectile body, that forms a transition from the driving band section to a portion of the projectile body adjacent to the driving band lead-on section on a forward side thereof. The driving band lead-on section can be formed having an LD-Haack profile.

Abstract: A projectile for use with a firearm having a rifled barrel including helical grooves extending longitudinally along an inner surface thereof can include: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section; a driving band section formed on the projectile body between the nose section and the tail section; a bore rider section formed on the projectile body between the nose section and the tail section; and a pilot band section formed on the projectile body forward of the driving band section. The pilot band section can be formed having an LD-Haack profile.

Abstract: A follower for use in a firearm magazine includes an elongate body defining a first plane extending between a first end portion and a second, opposite end portion. The first and second end portions define grooves therein that are disposed on respective planes oriented parallel to the elongate body.

Abstract: A projectile for use with a firearm having a rifled barrel including helical grooves extending longitudinally along an inner surface thereof includes: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section, a driving band section formed on the projectile body between the nose section and the tail section having a first diameter, a bore rider section formed on the projectile body between the nose section and the tail section having a second diameter different from the first diameter, and a pilot band section formed on the projectile body forward of the driving band section having a third diameter different from the first diameter and the second diameter.

Abstract: A follower for use in a firearm magazine includes an elongate body defining a first plane extending between a first end portion and a second, opposite end portion. The first and second end portions define grooves therein that are disposed on respective planes oriented parallel to the elongate body.

Abstract: A follower for use in a firearm magazine includes an elongate body defining a first plane extending between a first end portion and a second, opposite end portion. The first and second end portions define grooves therein that are disposed on respective planes oriented parallel to the elongate body.

Abstract: A follower for use in a firearm magazine includes an elongate body defining a first plane extending between a first end portion and a second, opposite end portion. The first and second end portions define grooves therein that are disposed on respective planes oriented parallel to the elongate body.

Abstract: A projectile for use with a firearm having a rifled barrel including helical grooves extending longitudinally along an inner surface thereof includes: a substantially cylindrical projectile body having at a front end an ogival nose section and at a rear end a tail section, a driving band section formed on the projectile body between the nose section and the tail section having a first diameter, a bore rider section formed on the projectile body between the nose section and the tail section having a second diameter different from the first diameter, and a pilot band section formed on the projectile body forward of the driving band section having a third diameter different from the first diameter and the second diameter.