Relum Supertornado - Part 2
by B.B. Pelletier
Okay, today I'll continue with the description of this rifle and test the velocity, as well. You may remember that the Relum Supertornado is an underlever that's loaded through a tap. A tap is a loading chamber that turns 90 degrees to accept a pellet, then realigns with the breech for firing. It's located in front of the compression chamber and behind the barrel. When aligned with the barrel for firing, it sort of forms an extension to the air transfer port because it's still behind the rifled barrel. So taploaders are usually lower-powered than other types of airguns that load directly into the barrel.
The Supertornado is a spring-piston air rifle, but loading taps have been used on precharged pneumatics, as well. Loading taps have to be as airtight as possible while still being able to rotate. That said, most of the taps I've seen and used have rotated smoothly and without great force. The tap on this Supertornado rotates with very little effort at all. However, there's one quirk. This is the only loading tap I've seen on a pellet rifle that rotates down. The handle moves counter-clockwise until its pointing straight down when the loading port is opened. On all other taps I've seen, the tap rotates clockwise and points straight up when the port is open.
When closed, the handle on the loading tap points forward.
The handle rotates down to open the tap. A pellet is now dropped nose-first into the tap, which is rotated closed to fire.
Quick check for the fit of the tap
One test to see how tight the tap is, is to let the piston go forward while the tap is down. This is done with restraint on the underlever to prevent the piston from slamming into the end of the compression chamber. I've had Hakims hold their pistons in place with the compressed air this way, however the tap on the Supertornado doesn't seal that well. There's a hiss of escaping air, but the piston doesn't pause when going forward.
When I cocked the rifle the first time, I could see why it's a favorite of the owner. The cocking effort is a mere 21 lbs. according to my bathroom scale. That is just one pound above my criterion for a youth gun! The single-stage trigger that was originally adjustable but now is not, pulls smoothly between 4.5 and 5.5 lbs. It's so smooth that it feels like a pound less.
The underlever has a ball bearing in its end that makes it hold tight to the socket, yet pop away from the barrel when you're ready for it. And the light cocking effort makes this an all-day rifle, for sure.
A large spring-loaded ball bearing holds the underlever in place.
Inside the rifle there are two mainsprings, one nestled inside the other. These two springs are wound in directions counter to each other to cancel any tendency for the rifle to twist or torque at firing. Owners of RWS Diana 48 and 52 air rifles notice this twist more than most spring rifle shooters because their rifles are slightly heavy on the right side due to the extra weight of the cocking lever, and the direction of the torque is also to the right but it's noticeable in many spring rifles.
When Jim Grossman acquired the rifle, he told me he cleaned out the powerplant, which was full of dried factory grease, and lubricated the two original springs with a light coating of Jim Maccari's spring-dampening tar (a thick viscous grease that deadens vibration). He learned that some UK websites tell how to upgrade the power with a Gamo or OX mainspring, but he was happy with the factory setup. So, let's see what the gun gets in terms of power and velocity.
The rifle fires without vibration. There's just a solid "thunk." And that, coupled with the easy cocking and smooth trigger, make this one endearing air rifle. If it also turns out to be accurate, it's a classic "go-to" airgun.
The Relum Supertornado is a .177, and we suspect that it has low- to mid-level power. So, I selected pellets that I felt were appropriate for that power range. RWS Superdomes were first to be tested. They gave a velocity average of 515 f.p.s., and the spread went from 503 to 529, for a total of 26 f.p.s. That's an average power of 4.89 foot-pounds.
I chose Superdomes for another reason besides their weight. Taploaders need pellets made of pure lead and those with thin skirts, because the air blast has to flare the skirt out to seal the tap. Otherwise, there will be some blowby air and the velocity will suffer. I'll show how in a moment.
The lightweight 7.5-grain Gamo Match pellet went a little faster. It averaged 562 f.p.s., with a spread from 553 to 571. That's a total of 18 f.p.s. Average energy with this one was 5.26 foot-pounds, or a little more than with the heavier Superdomes. This relationship (lighter pellet being more efficient) is to be expected from a spring-piston gun--especially one that's vintage.
Crosman Premier hollowpoints
Crosman Premier hollowpoints gave me a problem in the Supertornado, and they illustrate what I said earlier about soft lead and thin skirts. Premier hollowpoints weigh a nominal 7.9 grains, so they should be about as fast as an RWS Superdome. Perhaps slightly faster, because they're supposed to be almost half a grain lighter. But that wasn't the case.
These pellets averaged 487 f.p.s. But the real story is in the spread. It ranged from 397 to 518! A spread of 121 f.p.s. I was going to throw that 397 out as an anomaly, but on the 10th shot I got a 416 f.p.s., so it stayed in.
The problem, once again, is that a taploader needs a soft, thin pellet skirt that can be blown out into the walls of the tap to seal the air behind the pellet. Crosman lead pellets are all made from a hardened alloy that makes them well-suited to work through repeating mechanisms. While they're pretty much the standard for action guns, they do have a problem in most taploaders, and these velocity results show that as graphically as can be. The firing behavior on that slow first shot was also noticeably sudden and quick. I wouldn't say it was harsh, because it seemed to be the opposite of harsh. But it was different from all the other shots, and I could tell that while shooting through the chronograph. Had I gotten two more shots like it, I would have stopped right there, but it never felt that way again.
That takes us through velocity. Next stop are the bullseyes.