GB2367606A - Shotgun cartridge wad - Google Patents

Abstract

A wad for a shotgun cartridge is made from a biodegradable plastics material such as polyvinyl alcohol. The wad may comprise a base, a portion that in use collapses longitudinally, and a cup containing the shot.

Description

Cartridge wad This invention is concerned with a cartridge wad, and relates in particular to an environmentallyfriendly, biodegradable, wad and shot cup for use in shotgun cartridges.

Cartridges for shotguns take the form of a short (around 65 mm, or 2.5 in) card or plastic tube with at one end a brass termination-the"head"-containing a percussion cap. The tube is filled with a small amount of propellent, which is retained against the inside of the head (and the"active end"of the percussion cap) by a wad, and the space in front of the wad contains the shot. The shot is held tightly in place by a"crimp" which is itself secured at the mouth of the tube by the latter's rim being rolled over onto it.

In modern cartridges it is common for the shot to be confined within a short tubular holder-a shot cup that is a snug fit within the cartridge tube, and this cup is usually made of some plastic, typically a polyalkylene such as polyethylene. The wad was originally made of a compressed fibrous material of plant derivation, but these days it too is commonly a plastic. And, very often, the plastic wad and the plastic cup are for convenience combined into a single unit, which is simply referred to as the wad.

When shooting at game, as opposed to shooting at clays (skeet shooting), the gun-that is, the person doing the shooting-will be firing over agricultural land, whether woodland, arable or livestock, and may be at a stand, with the game driven towards him orespecially when"rough"shooting-may be walking over the land shooting at game that is flushed out as he goes. In either case, but especially the latter, as the shoot progress he will be discarding spent cartridges whenever he reloads. These are quite brightly coloured, and after the shoot is over they can quite easily be found, and be picked up and disposed of (sometimes re-loaded). They do not, therefore, hang around, with the possibility of have any significantly harmful effect on the environment.

However, the same cannot be said for the wads. Not only are the wads scattered far and wide as the gun fires to left and right over a large area, but the modern plastic versions are usually made from a relatively colourless, "white"plastic that is difficult to find and retrieve, and are just the right size to be a mouthful for an inquisitive animal. A plastic wad stuck in the gut of a sheep, say, can cause severe pain, and even death.

The present invention relates to a solution to this problem, and in a particularly neat way. Rather than make wads easier to find, or less attractive to eat, the invention suggests that they simply be made of a material-a plastic material-that is essentially biodegradable, and that will, after a few weeks on the (damp) ground will disintegrate to the point where it no longer presents any significant danger to an animal.

In one aspect, therefore, this invention provides a wad for a shotgun cartridge, which wad is made from a biodegradable plastic.

The term"wad"as used here means the combination of propellent-retaining wad and shot cup, as is presently utilised in most shotgun cartridges.

The wad can take any appropriate physical formany of those presently used will be satisfactory, and no more need be said about that here. Typically, however, it is in three main parts; a base forming a true wad portion, then integral therewith a crushable portion that collapses longitudinally as the propellent burns and the internal pressure builds up, and finally, and integral with the crush portion, a tubular shot cup portion the side surface of which is cut into four elongate leaf sections (which open out like petals to increase drag as the wad exits the gun barrel, so that the shot leaves the cup and flies on ahead).

The invention is a wad for a shotgun cartridge.

The cartridge may be of any type (with any of the usual propellent charges and shot contents) and of any sizethus, it may for example be a game cartridge (for pheasant, duck or pigeon, say) or a skeet cartridge (for shooting clays), and it may be a 12-bore, a 20-bore, or a. 410 (these are common British gun sizes).

The biodegradable plastic may be any such plastic, but especially one that is injection-mouldable (this being the preferred way in which such wads are usually shaped). A particularly convenient such plastic is a poly-vinyl alcohol (often referred to as PVA, or PVOH), one such being one of the range of Ecomaty AX materials - the AX-2000, AX-300 and AX-50-available from Nippon Gohsei, of Osaka, Japan.

The invention provides a cartridge wad that is rather more environmentally-friendly than those used up to now. If left in the open it will, over a few weeks, dissolve or disintegrate, or otherwise fall apart into a relatively innocuous state. Even if actually eaten by an animal it will rapidly decompose and disperse in the animal's stomach, leaving the animal unharmed.

Claims (5)

1. Claims 1. A wad, being the combination of propellentretaining wad and shot cup, for a shotgun cartridge, which wad is made from a biodegradable plastic.
2. 2. A wad as claimed in Claim 1, which is in three main parts; a base forming a true wad portion, then integral therewith a crushable portion that in use collapses longitudinally, and finally, and integral with the crush portion, a tubular shot cup portion the side surface of which is cut into four elongate leaf sections.
3. 3. A wad as claimed in either of the preceding Claims, wherein the biodegradable plastic is injectionmouldable.
4. 4. A wad as claimed in Claim 3, wherein the plastic is a poly-vinyl alcohol.
5. 5. A wad as claimed in any of the preceding Claims and substantially as described hereinbefore.