Jonathan Young takes a close look at the Gamo R-77 – a collectable CO2 revolver from the 1990s that offered plenty of choice and plenty of features
Back in the 1990s an iconic CO2-powered pellet-firing revolver arrived on the airgun scene from Spain — the Gamo R-77. Made from a combination of metal and plastic, this handgun has provided a good mix of accuracy and fun over the years, being a lightweight revolver available in .177 calibre only and having a rifled barrel. It has an authentic full-size swing-out cylinder magazine, and for anyone starting to yawn who owns a modern shell-loading revolver, do remember this pistol came out three decades ago.
Eight pellets are loaded into the rear of the cylinder, which is released by a small knurled steel stub screw. It’s located on the barrel assembly to the front of the cylinder, rather than the fake button moulding to the pistol frame, which can catch some people out.
Thanks to the rear cylinder loading system, there are no restrictions when it comes to pellet length – and that’s a real plus over many other CO2 pistols. A functioning adjustable rear sight and a left-to-right hammer safety come as standard. Barrel options were a dinky 2.5in, a 4in and a rarely seen 6in.
Most of these pistols were marketed as the R-77 Combat and were fitted with big grey rubber grips. These grips are superb, having a positive and secure attachment to the frame. There’s little fear of having any broken clips or catches as they are made of a tough but bendy nylon, and form part of a separate nylon plate that is moulded into the rubber.
Because of this, custom grips are unfortunately near impossible to get, needing a total rethink. Another version on the same basic R-77 platform was the Combat Laser, a 4in model with a modified hollowed lower barrel assembly fitted out with a laser inside.
No R-77 6in Combats appear to have been offered for sale, not even within Spain. The 6in barrel appears to have been unique to the special and rarely seen R-77 Classic, which is sometimes referred to as the M and is fitted with walnut grips.
The combination of a long barrel and wood gave this gun a classy look that is not normally associated with the chunky R-77. Additional markings on this special model show M and 6 painted in white to the left side of the frame. The M is for Madera, indicating the wood, while the 6 refers to the unique barrel length. Today, used Classic M6s rarely appear for sale here, and they may never have been imported into the UK.
The R-77 grip area has a narrow frame. Early units, especially those with 2.5in barrels, came with sculpted grips in a hard brown plastic to match this slender profile. These gave the R-77 an unusual Police Special look nearly 20 years before the current BB shell-loading Asian imports. Later 2.5in units were sold with the newer rubberised grips as on the 4in model, creating a pistol that handled nicely, but without that unique pocket pistol look.
The barrel assembly on all R-77s is composed of an inner rifled steel barrel held inside an outer hard nylon shell that’s been moulded on, so is non-removable. Spare barrel assemblies in different lengths were difficult to find, but some have appeared recently.
Swapping barrels is easy, as a small grub screw on the frame between the open sights pinches the barrel, and removing this allows the barrel assembly to be pulled out of the frame. Replacement is the reverse, but it is a tight fit.
Thankfully the barrel crown is recessed in its outer casing, so should never get damaged. The barrel plastic moulding has cast-in markings, while the frame has Gamo identification marks usually on the left-hand side in large white lettering, although oddly some units are seen without these.
The unusual and sometimes overlooked feature on the R-77 is how good the sealing is for a CO2 revolver. Squeezing the cylinder hard against the spindle on the opening magazine pivot, there is some minor compression, and dismantling the cylinder’s hex bolt reveals that there is a large juicy O-ring on the spindle. Each hammer blow creates forward cylinder movement, sealing the front of it against the barrel face then easing off for snag-free cylinder rotation.
To the rear the valve stem protrudes forward, as with any valve on firing, but the exhaust tip has a rubber sealing sleeve. This presses against the rear of the pellet chamber so, in effect, there is a gas seal to the rear and to the front at each discharge.
The tiny valve head has a very small valve stem, but freeflow tunes have been attempted. The steel used by Gamo for this part is extremely hard, and working a needle file into such small exhaust ports is time-consuming. Some gains have been noted when used with the longer 6in barrel, however, making a fun pistol just a little more usable.
The barrel breech end can touch the moving cylinder too much, which if you remember moves forward with each shot. Watch out for worn exhaust stem sleeves that can tear or literally disappear. If a pistol has really low muzzle velocity, but no obvious gas leaks, this should be checked out first.
There should be a good solid black rubber sleeve just visible around the exhaust end of the valve stem when lying flush with the frame surface. This can be easily overlooked when buying a used pistol. To check the condition or to replace it, I open the empty cylinder and, with no gas bulb present, cock the hammer back, then use a tool to press the valve stem forward from the rear, pushing the front exhaust out. The rubber sleeve will present itself or not.
Replacement sleeves are breech seal part no 19580. On one unit this had disappeared, so I placed a new sleeve on the tip of my finger and slipped it over the protruding stem. Warming the seal and oiling it to make it stick to my fingertip helped, but these are fiddly and a tight fit and it took many attempts, especially as the valve spring is very punchy. Sometimes a total stripdown may be called for. I work slowly and photograph every stage for part placement.
Are there any bugbears with this gun? It’s possibly too light, especially for some shooters, and the unnecessary markings are a pain for authenticity. The removable side-plate to the right is festooned with moulded lettering and warnings and it’s plastic, which is a shame when the rest of the frame is metal. Some owners have even sanded these markings away.
On some units the magazine cylinder can open of its own accord. The locking catch is a hard steel pin that can wear the plastic cylinder. This pin and its spring are held in place by the knurled steel screw that is used to unlatch the cylinder open.
This cylinder release screw part no 18080 can be removed to ease disassembly, but trying to fix this problem can be counterproductive. I have instead bought a second unit, broken or with leaks, so I can swap the cylinders over, making for one decent usable pistol and a very worthwhile pile of spares.
More recently, the R-77 has been barely recognisable, fitted with Picatinny rails and called the GR-Stricker. The original Gamo R-77 is very underrated. It’s a very interesting and effective CO2 revolver and definitely a personal favourite.