Theoben Sirocco and Eliminator

Theoben Eliminator

Model: Sirocco Classic
Manufacturer/Importer: Theoben
Powerplant: gas spring
Calibers available: .177 .22
Caliber tested: .177
Power: up to 23 ft/lbs
Velocity: 900-950 (under test)
Retail price: About $900 (1995 price)

Model: Eliminator
Manufacturer/Importer: Theoben
Powerplant: gas spring
Calibers available: .177 .22 .25
Calibers tested: .22, .25
Power: Up to 30 ft/lbs
Velocity: 900-950 (under test)
Retail price: About $1200 (1997 price)

Theoben is a small company based around a novel innovation- a pressurized gas ram used in place of a steel spring in an otherwise traditional spring air gun. While they have since branched out into other guns- most noteably a series of precharged pneumatic repeaters, beginning with the Super 7, their gas spring guns are still their main product line.

The Sirocco was one of the earlier Theoben designs; it was out of production for a while, having been replaced by newer (and in some cases less expensive) models such as the Fenman and the Taunus, but was reintroduced in an improved version after a few years. These newer guns offer an improved gas ram system that offers greater efficiency and shorter lock time via a gas ram with a shorter stroke operating at higher pressure. My test gun was updated to the improved gas ram, so these comments rrefer to the improved gun, but the original guns are by no means poor performers.

Most of the Theobens made for the domestic market are 12 ft/lb guns; the only remaining FAC rated (over 12 ft/lb) spring gun in the Theoben line is the Eliminator, also marketed by Beeman as the “Crow Magnum”; the Sirrocco is very similar to the Eliminator, but is a bit lighter and smaller. It was available in a standard field version, the Classic, as well as a field target version, the two differing in the stock supplied.

All the Theoben guns are very smooth and easy to cock, and this one is no exception. Fit and finish are execeptional, with all metal parts having a very high degree of polish. Accuracy is very good, owing to the extremely short lock time and consitency of the gas spring as well as the high quality of the barrels used. It’s more than sufficient to group Crosman Premiers on a dime at 40 yards. I suppose I can best summarize the Sirocco by saying that it has replaced all my other spring guns for hunting and plinking.

The Eliminator shares all the positive attributes of the Sirocco, and adds about 50% more power. This doesn’t come free, of course; when set to its maximum of 30 ft/lbs, cocking the Eliminator is a pretty good workout for the arm muscles. For hunters this is not really a problem, but it does rule casual plinking out for most of us. Set to about 26 ft/lbs it’s a much more managable gun, but still requires a bit of work. Firing behavior is like the Sirocco- smooth and vibration free.

Both of these guns are very finely finished, with stocks made from attractive woods, and mirror-smooth polishing on exposed metal parts. You do pay extra for this attention to detail, but when buying a gun with this level of attention on the inside, it makes sense to have the same level of attention and detail on the outside as well.

The Combustion Myth

Back in the 1950s the father and son team of G. V. Cardew and G. M. Cardew published the results of an interesting study in which that proposed that a large part of the power of airguns came from the combustion of lubricants in the compression chamber of spring-air guns. Thier experiment was simple, and convincing: They fired a .22 cal Weihrauch HW 35 that had been purged of air and filled with nitrogen. Muzzle velocities obtained were significantly lower than when the gun was fired in air.

I’ve always been somewhat distrustful of the Cardews’ experimental methodology, which involved placing a gun in a plastic bag, pumping out air, and bleeding in nitrogen, and then opening the bag and firing the gun, but I’m willing to believe it worked, and that they obtained the results they published. Certainly these guns were burning part of their lubricant; anyone who’s owned a Daisy BB gun is familair with the wisp of smoke and the smell of burning oil that follows a shot from a well-oiled gun.
The airguns of the Cardews’ era had leather piston seals which had to be fairly well saturated with lubricant in order to provide a good seal. Some of this oil would invariably be sprayed into the barrel in the form of a very fine aerosol on firing, and that aerosol would in turn be ignited by the hot air coming through the transfer port, and that would add to the propulsive power of the gun.

But there would also be lubricant burning in the compression chamber- and that should interfere with propulsion, by setting up a shock wave that would drive the piston back before maximum pressure was built up in the barrel. I have, on a number of occasions, encountered just such a situation in guns in which some combustible material- usually a pellet lube or cleaning solvent- has gotten into the chamber. The result is usually a loud report, a blackened (and sometimes ruined) piston seal, often a damaged mainspring, and a drop in muzzle velocity.
And there’s another issue. But in the 1960s, Ladd Fanta started experimenting with using silicone oils- which do not burn- in place of the combustible hydrocarbon oils traditionally used in air guns. Airgun dealer Robert Law also began promoting the use of these new lubricants. And looking over some of the catalogs that Law produced back then, no where does he mention any loss of velocity from using silicone based lubricants. So I remain- let’s say- skeptical, but open to being convinced.

Whether or not the Cardews’ test showed what was claimed, the results still have no applicability for today’s guns. Modern airguns- which the possible exception of some of the very cheapest Chinese guns still sitting in a warehouse somewhere- don’t use leather seals. Any lube beyond a fraction of a gram is quickly shot out. Modern synthetic lubes are made of silicone- a tightly bonded silicon-oxygen molecule that simply will not burn. And despite using only a miniscule amount of lubrication, and being fired regularly for years or decades without any additional lubricant, today’s spring airguns commonly achieve muzzle energies and velocities unheard of in the Cardews’ time.

The Beeman R7

Manufacturer/Importer: H. Weihrauch/Beeman
Powerplant: Coil spring
Calibers available: .177 .20
Caliber tested: .177
Velocity: 650fps (advertised) 550-575 (under test)
Retail price range: $260-330

The Beeman R7 is, like most Beeman guns, a ‘customized’ version of another gun, in this case the Weihrauch HW30. The Beeman version differs from the standard HW30 in that it has a different stock- styled more to North American, rather than German, tastes- and it can be obtained in .22, .20 and .177 calibers.

Like other HW guns, the R7 is a very finely made piece, with a well-machined and polished metal surfaces, superb metal-to-metal fit and smooth action. The trigger is the simpler version of the well-regarded HW ‘Rekord’ trigger unit, an adjustable 2-stage trigger with no discernable creep and a very smooth let-off. The factory test target (typical with HW guns) supplied with my unit suggested a very high degree of accuracy, the 5-shot group making one ragged hole.

While the stock R7 is a bit underpowered for hunting, it it powerful enough for close-range dispatching of crows, mice and other small vermin. It’s also very accurate and well deserving of a good scope or aperture sight. My first custom addition to this gun, shortly after I bought it, was a Williams aperture sight designed for .22 rifles. I used this for a number of years before I decided to mount a scope instead as a concession to longer distances and aging eyes 😉

As is typical of spring air guns, the unusual two-way recoil demands a scope designed for air rifle use rather than a cheap .22 scope. It’s a good idea to add a ‘recoil block’ to the scope grooves as well. Even though this is a rather low-powered rifle, the combination of the spring recoil and the gun’s light weight will result in most scope mounts shifting quite a bit. I’ve used a few different scopes on this gun, my favorite being the no-longer-made Beeman SS-1 (actually made by Hakko, a Japanese optics maker), a very compact and high-quality 2.5×15 rubbered armored unit with built-in mounts.

Beeman offers the R7 is .20 caliber in addition to the standard HW offerings of .177 and .22. I personally don’t see any advantage to the larger caliber versions; this is really more of a marketing decision by Beeman than a real advantage. Beeman’s volume purchasing allows them to contract for exclusive version of guns in .20 caliber, which allows them to offer unique models. The R7 is best purchased in .177 caliber, which gives the shooter a wide range of pellet choices at the lowest cost. I would recommend lighter pellets in the 7 grain range for the R7, and I have had good luck with HW and RWS match pellets, as well as with the Beeman Silver Bear pellets.

I’ve owned my R7 since about 1982- it was my first ‘quality’ air rifle, though I had a few Crosman and Daisy guns before it. After a good many years of pretty regular use, the gun is more or less like new, save for a few scratches and nicks. The only major repair done in that time has been a mainspring replacement, not an unusual thing for a gun that has had this much use. Spring replacement is fairly easy, and can be done in about 30 minutes with two screwdrivers, a pin punch and some sort of fixture for compressing the mainspring. I use a pipe clamp and a couple blocks of wood or aluminum, a system that seems to work well for guns up through medium power.

Overall, the R7 gets very high marks from me. It’s small and light enough to carry all day for an afternoon of plinking, and its light weight and size also make it ideal for small adults or young teens. Although I’ve bought and sold a great many air guns since buying the R7, I’ve never contemplated selling mine.

The Beeman R1

Model: Beeman R1
Manufacturer/Importer: H. Weihrauch/Beeman
Powerplant: Spring
Calibers available: .177 .20 .22
Caliber tested: .177
Velocity: ‘Over 1000fps’ (advertised) 850-950 (under test)

The Beeman R1 is another example of a special version of an Weihrauch gun done up to Beeman specs, in this case the HW80. When it first came out some years ago, the R1/HW80 was probably the most powerful spring/air gun on the market. Since then it’s been followed by other guns from Weihrauch, Webley, Theoben, RWS and others, but the R1/HW80 is still a very popular gun and an excellent example of how to produce a high quality, high-power spring air gun.

The trigger is the excellent Rekord unit, and as always delivers an exceptionally crisp let-off with no creep. The 2-stage trigger is adjustable over a wide range for weight. My example delivered good accuracy, but had a barrel angle that was about as large as I’ve seen on a break-barrel gun, necessitating a large amount of tilt dialed into the scope mounts. This also prevented me from using a large aperture 4-12×40 scope on my R1, as the excessive tilt required caused the objective end of the scope to hit the receiver. This can be fixed, with some careful machining, but generally it’s best to make sure the gun you buy doesn’t have this problem in the first place.

This is, after all, a gun that really demands the use of a scope. The R1 is perfectly able to take rabbits and similar sized game at 40 yards, and the supplied open sights don’t really perform well on tiny targets at that distance. A good 4 power scope, or a 2-9x variable makes a good match for the R1. It’s especially important to get a well-made airgun scope for this gun, as the recoil is especially harsh. It’s not so fierce as too cause real discomfort to the shooter, but the two-way snap *will* destroy cheap scopes in a jiffy.

Depending on the pellet chosen, you can as much as 1000fps out of the R1 in .177 caliber, but using the light pellets needed to obtain this velocity (6-7 grains) is not a wise idea. Pellets this light don’t really provide enough resistance to the spring and piston, and result` in excessive “piston slam” that leads to damage to the seal and piston as well as early spring failure. Pellets should be chosen to keep the velocity of the gun under 1000ftps; the heavier 10.5 gr Crosman Premiers are a good choice in this gun.

Given that the R1 is really intended as a hunting gun, .22 caliber is perhaps a better choice than .177. Besides keeping velocities down, the .22 pellets deliver slightly more muzzle energy owing to more efficient use of the spring’s energy. But .20 cal is even better- at least with the Crosman Premier pellets. The .20 cal Premiers have the same mass as the .22 version, but much higher sectional density. The result is muzzle energy very close to that of the .22 version with significantly higher downrange energy and flatter trajectory. [n.b.: This was borne out by actual testing when I traded a CO2 gun for a .20 cal R1 some years after this refview was written.]

Cocking the R1 takes a bit more muscle than does cocking a lesser powered gun, but it’s not really that bad. A day’s hunting or plinking wouldn’t tire you out. Still, it’s not a gun for young kids and smaller adults.

Overall summary: An accurate, well-made, powerful gun that’ll last forever if you take good care of it.