While my first article on Japanese airguns looked at the Sharp Innova and Ace multi-pump pneumatic rifles, I’m following up with a far more exotic offering from the Tokyo-based airgunmaker – the slide-action GR75 CO2 rifle.
Sharp’s first CO2-powered rifle design saw light of day in 1967. Known as the Sharp CO2-5, it was a five-shot semi-auto CO2 rifle in .20 calibre, where five shots could be fired as fast as the user could operate the trigger!
Rather like Crosman’s famous Model 600 semi-auto pistol, this was a pretty amazing feat at the time.
Sadly, I’ve never seen an example of the Sharp CO2-5, and although a small number were exported to the USA, none were imported to UK gun shops. If any collector has brought one to our shores, I’d be extremely interested to hear about it ‘in the flesh’.
After the CO2-5, Sharp then appears to have concentrated on various single-shot designs, but all that changed in 1975, with the arrival of their GR75 – a five-shot, slide-action repeating CO2 air rifle, an example of which you can see in figure 1.
Many readers will already be familiar with either the Crosman Model 622, or more likely the Gamo 1200 – both slide-action repeating CO2 rifles – but in terms of quality and attention to detail, neither can hold a candle to the Sharp GR75.
Oddly, Sharp only produced their GR75 rifle in .20 calibre; quite why is open to question.
With the exception of the earlier CO2-5, all of their other models were produced in either .177 or .22, so the one-calibre-only option on the later GR75 seems particularly strange.
Perhaps they saw Sheridan’s pursuance of .20 calibre as being a good way to win over the American market?
As you can see from figure 1, the rifle’s design shares a remarkable resemblance to a pump action rifle/shotgun from either Remington or Weatherby.
The operation of this air rifle is detailed in its accompanying owner’s manual (figure 2) which shows the GR75 fitted with a telescopic sight, although as all the text therein is in Japanese, much of its advice must be left to chance!
Overall, the sample shown here measures 990mm (39in) with a 495mm (19.5in) rifled steel barrel.
It tips the scales, unscoped, at 2.98 kilos (6lb 9oz) and sports a two-piece hardwood stock – the slide-action forestock and butt – which appears to be Japanese walnut.
The pistol grip cap and butt plate are made of black plastic, with white line spacers on both making for a very classy look.
The GR75’s barrel is mounted above a larger diameter lower tube, which is the expansion chamber housing twin 12-gram CO2 ‘bulbs’.
Both barrel and tube are secured by a cast steel bracket that’s positioned in front of its sliding wooden forend, directly behind where the knurled retaining cap assembly threads into the tube (figure 3).
Out of the box, the GR75 was fitted with a ramp foresight (figure 4) and a basic rearsight unit (figure 5), both of which were fairly generic to Sharp’s range of rifles.
Additionally, it also features a ramp with standard 11mm (3/8in) dovetails along the top of the receiver onto which the owner could mount an optional telescopic sight. This can be seen, along with a close-up of the right-hand side of the receiver, in figure 6.
As you can see, the GR75’s steel action features a classic sloping back, beloved by many users of both semi-auto and pump-action shotguns.
In keeping with this design element, the cast trigger guard is also a sweeping affair, featuring a chrome-plated push-button safety to its front.
Figure 7 – the left side of the action – details the cut-out slot toward the top of the receiver which takes the spring-loaded, black plastic magazine.
This was designed to hold five pellets in .20 calibre, which you can see installed in close-up in figure 8.
The GR75 works in true pump-action style! Sliding the wooden forend back, toward the action face, cocks the hammer and allows a loading shuttle to move across in line with the magazine to take a pellet.
Returning the forend to its forward ‘stop’ position then takes the shuttle – now loaded with a pellet – back in line with the barrel, and ready to fire. In theory, it’s a very fast-action system.
On seeing this rifle, my first impressions were just how attractive it is.
The preparation of the barrel and expansion tube prior to bluing are exemplary, with the barrel exhibiting a finish easily comparable to the very best from Walther or Webley!
This is complemented by the finish on the action, which has to be one of the best black, spray-painted finishes I have ever seen, and the particularly pleasing grain pattern on the stock which has also received a decent varnish treatment.
To charge (gas-up) the Sharp GR75, you first remove the knurled tube cap on the front of the expansion tube (see figure 3).
Next, insert a 12-gram CO2 bulb into the tube, its base-end first, and insert the double-ended piercing collar, followed by a second bulb, this time inserted neck first. The internal layout is shown in figure 9.
With the bulbs inserted, screw the tube cap on until it stops, and then turn in its external screw until you feel it contact the end of the bulb.
Slide the forend all the way back to cock the action and then forwards again until it stops. Pointing the cocked (but unloaded) rifle at the ground, squeeze the trigger… and the dry-firing cycle will pierce both bulbs, allowing the gas to flood into the chamber.
The GR75’s plastic magazines are of a fairly complicated design which can initially be quite awkward to load, though getting the knack comes with use.
Small alloy clips are provided to fit over the ends of loaded magazines to help prevent involuntary discharge of pellets prior to them being put into the rifle. Very useful indeed – you can see one in figure 7.
Five pellets are loaded into the magazines, skirt first, against the pressure of a small spring, and the last pellet is then retained by a tiny lip on the magazine body.
I found this to be the worst feature of the design as it’s all too easy to end up with all five pellets springing straight out of the magazine and shooting across the room!
And the GR75 must be the ultimate in ‘pellet fussy’ rifles! Originally designed to fire Sharp’s own .20 calibre pellet, the only pellet I’ve found that will both stay in the magazine and cycle in the rifle is the 11.44-grain Beeman Silver Ace (figure 10).
Manufactured by the firm of Hasuike Seisakusho in Japan, these specialist pellets feature a twin-ring head and are a very close match to the shape of the original Sharp pellet.
Thankfully the owner of the rifle I’m featuring here supplied a box of these for me to try – but that’s where the good news ends…
Positioning the magazine in the action is another acquired skill, but once in position, the GR75 cycles extremely smoothly and the pellet is released by a firm, but smooth, pull on the oddly-shaped trigger blade.
Normally at this point, I’d be testing the rifle on my usual range and providing copies of my test targets.
However, on this occasion I can’t provide a sample card because, despite my best efforts, the GR75 proved impossible to zero due to frequent jams.
This was mainly caused by the nose of the following pellet partially entering the skirt of the previous one, which would not then allow the pellet shuttle to move over, into line with the barrel.
Generally, this rifle would only fire between one and two shots before it jammed, requiring the shooter to remove the top cover from the receiver before access could be gained to clear the stuck pellets.
Frustrating, to say the least – but I can report that those pellets which actually connected with the target, all shot nicely to the point of aim.
The rifle’s owner is convinced that the problem lies in the design of the magazines, which do not appear to restrain succeeding pellets in the line sufficiently enough to prevent them entering the one in front – in other words, a major design flaw.
He uses Silver Ace because the magazines ‘catch’ (and so retain) their twin rings much better than any standard waisted .20 pellet.
It may be that a more suitably-shaped pellet could solve the jamming problem – but with the choice of .20 calibre pellets being quite restricted, it’s not an easy fix.
I did manage to check some shots over the chronoscope, which clocked around 540fps; roughly 7.41ft/lb in power terms.
Despite its obvious failings, the GR75 would still be the ‘jewel in the crown’ to a collector of Japanese airguns as, make no mistake, this is a rare rifle to find in the UK.
Spare parts for these rifles, however, are non-existent and such things as valve seals would have to be made up.
O-rings are available from specialist suppliers, but do bear in mind that they are in Japanese sizes, which are somewhat different from our own.
Because of its rarity in the UK, it’s quite difficult to give an indication of value; however, due to its quirks, I would expect most examples to range from very good to mint condition as they will most probably have been little used!
With this in mind, I’d expect a collector to pay anything from around £350 up to, say, £550 for a boxed, mint example.