A custom airgun with an unconventional barrel is joy to use for rats and pigeon, says Bruce Potts
Steve Harper is one of the old-school airgun makers in Britain. Famed for his innovative Harper classic guns, his fortes were his precision-made air canes and air cartridge firearms and pistols, many bearing his electronic triggers. Based in his Buckinghamshire workshop, Steve now spreads his time between classic one- offs and designing innovative systems for modern guns, such as Daystate’s electronic circuitry.
This is an unusual Harper Classic in the guise of a Weihrauch HW90 gas-ram air rifle, which has been converted to .25 calibre before Weihrauch offered a .25 barrel. It wears Steve’s distinctive brass medallion inset in the breech of the HW90, denoting a non-standard Weihrauch.
Very clever rifling system
Instead of using an aftermarket .25 barrel, Steve has opted to go the custom route and re-bored the old .22 barrel to accept his own home-grown .25 brass tube. Look down from the breech end and the barrel’s interior is anything but conventional. Usually, you will have between five to eight rifling lands — sometimes three, like my fast Wildcats —but Steve’s barrel is different.There is a total spiral rifling system with 20-plus rifling lands; slim and shallow rifling that provides good rotational grip but with a little frictional force to remove lead and deform pellets. It’s very clever.
The barrel is also short at 10in, as being a .25 calibre it utilises air more efficiently than the smaller.177, .20 or .22. This allows a shorter overall rifle design. It is fitted with the efficient Panther sound moderator from Michael Tawn airgun supplies. It is large enough to mute the muzzle report to a slight “thut” but, interestingly, it is elliptical in design. Here the barrel rides in the top section, and the baffles to mute noise are sited below the axis of the bore.
Good for pigeons and rats
This Harper Classic was reduced in power by its owner to 10ft/lb instead of the full 12ft/lb as it was used to topple feral pigeon off chimney pots and factory gantries. Thus the pellet stayed inside the pigeon for maximum striking force yet provided no problems with over-penetration that could break a window or roof tile. The rest of the Harper classic is pretty standard with an original stock that needs no further modifications. As this is a rifle to be used, a few scratches add to the history.
The action is a collaboration between Weihrauch and Theoben Engineering using a gas-ram propulsion system instead of a spring. Air is stored within a pressured chamber which, when cocked with the break barrel, compresses it behind the piston. When you squeeze the trigger, the pressure is released and the piston travels down the action, compressing atmospheric air in front of it and propelling a pellet through the barrel.
It does this with a very fast lock time and therefore firing cycle. Pressure can be altered via a bicycle Schrader valve system sited at the rear end of the action using a special pump.
Due to the fact that these are one-offs or designed to a client’s own specification, they are now rare classics and hard to find, but great fun to shoot. This model was best suited to Milbro Rhino .25 pellets that weigh 19 grains and, when shot at 487fps, deliver bang-on 10ft/lb energy. At 20 yards at this power setting, you can achieve pellet-on-pellet accuracy that no small pigeon nor rat can avoid.
What to look for when buying a secondhand Harper Classic .25 HW90
Barrels: Precision-made custom bore with numerous thin rifling lands to stabilise but reduce friction for excellent accuracy with a number of pellet weights.
Action: Power levels can be altered with this gas-ram system; this is set low at 10ft/lb for close-range rats. Brass inset on breech authenticates as a true Harper Classic.
Features: Superb build quality with custom barrel for the classic .25 calibre.
Price: Unique, you pay your price