RDT ARCHERY’S SCORPYD CROSSBOW
One cold Winter’s afternoon a few years ago, I was over at Bow-Plus, the pro-shop that imports crossbows to Britain for my reviews, talking over a coffee with owner Dave Horder about crossbow that might be interesting to review, and he told me about the reverse-draw concept bow mad by Jim Kempf, whom he had met at one of the international shows. Essentially, the reverse-draw concept involved mounting the prod of what was a compound crossbow with the string on the target side of the riser, implying that the string was, as it were, pushed towards the riser instead of pulled away from it as one does when drawing a conventional bow. Dave reported that, on the prototype, the standard of engineering was high, the design radical and the performance seemed good. He also advised that Jim Kempf was a very pleasant man and I should get in touch with him.
I telephoned. It took a few attempts to get through because it was cold there too and Jim was out feeding the deer in the snow. We talked for a while, I found myself becoming more and more intrigued by the practical implication of this design; evidently quiet in operation, low string wear, low vibration and recoil, low draw weight and high arrow speed. Of course, I offered to write a review, but production was as yet some way off. Jim promised to send me a bow as soon as there was a production model to send. I think it must be three or more years now, but after working tirelessly on the project, and with Scorpyd Crossbows now trading, Jim was as good as his word.
The appearance of this bow is striking; an aesthetic born of form begetting function through a brilliant design concept and sound engineering. It is so radical, it is hard to know how to set about describing it, other than to begin at one end and take it a step a time.
A solid alloy stirrup is formed with an integral projecting plate, rebated to accept what is an extended hard-anodized alloy extruded mainframe, and to which it is fastened by machine screws, properly addressing the principal stress component as shear-strain, rather than dependence on a thread not pulling out. Already we are seeing the sound engineering principles, which dominate the construction of this crossbow.
The Scorpyd’s Claws
The stirrup supports a pair of BowJax string stoppers, CNC drawn, the shape indicating intentionally that this is clearly by design, the stirrup smoothly reinforced by increased breadth in way of the mounting points. As the geometry is reverse-draw, the next item encountered as we move along the bow is the string, resting against the stoppers; the cables, properly separated by a cable-slide housed within the frame. String and cables are by Winner’s Choice.
The compound cams are very large for a crossbow, CNC dream, nicely machined and turning on sealed ball bearings with stainless steel axels. They are equipped with apertures designed to accept a peg, which enables the changing of a worn string in the field. Split limbs are well finished, Gordon Glass, tipped with Limbsaver strips, and sweeping gently back to the riser in a near-parallel configuration. The riser is a nicely machined alloy, with a very solid feel although ventilated, and I could detect no movement relative to the mainframe under all the torque my arms could muster before and after the test.
Alloy limb pockets, well machined from solid billet, are fitted at the riser with pivot bolts and secured by conventional limb bolts properly threaded into transverse barrel bolts rather than the alloy of the riser itself. Neat plates and lugs separate and align the limbs in a superbly executed construction. During a long and hard test, absolutely nothing moved or loosened.
Ambidextrous safety catch buttons, brass, are visible and accessible, either side of the latch housing above the pistol grip. The latch housing, again solidly engineered and well finished, is topped by a Weaver-Style sight rail. The arrow retainer spring is in the conventional position but of a design, I have not seen before and made of a plastic compound which when flicked with the finger is very quiet. This deals with what is conventionally a significant noise-component, here integrated into a crossbow, which is quiet through design.
Aluminum parts are aircraft grade. The stock is glass filled nylon wi9tha folding after section. There is no conventional detent, the stock is held in the closed position by a powerful magnetic latch. Reach to pull is fixed at 14 inches.
The whole test bow was finished in a matt tactical black. With its limbs facing forward like the claws, which account for its name, the Scorpyd possesses and aesthetic form, which begs to be admired as a pure sculpture, but its entire presence, declares its purpose as a pure hunting bow. The Scorpyd looks, and as I would discover is, deadly.
The Scorpyd comes with a DVD and a stern admonishment to view before using the bow. In the DVD, Jim demonstrates the working of the bow and there is an especially interesting section devoted to the mechanism and function of the dry fire inhibitor. Like the rest of the bow, it is an exemplar of precision engineering and ingenuity.
One of the arrows supplied with the bow was damaged. As usual, when the bow arrived at Bow-Plus, Dave Horder had felt obliged to verify that it was functioning properly – his reluctance for which duty evidenced by the teethmarks on the wrapping and the fact that at the time of writing he is setting about becoming the British agency Scorpyd – and his second shot clipped the cock-vane of the first. Arrows are 22” and must be moon-nocked or the dry-fire mechanism will not be deactivated and the bow will not release.
The sight with the bow was a 3X multi-Reticule crossbow-specific telescopic sight by Falcon. This is an excellent sight, from a British/American company, which I plan to test on several crossbow and review separately in a dedicated article.
Spanning or cocking the bow by hand is not recommended because of the narrow string angle and a cocking rope is supplied with the conventional theoretical tow to tone advantage, with of course some loss to friction in practice. Using this already light 125 lb draw weight is very manageable, although setting the length of the rope to suit one’s height is critical owing to the long power stroke. The evolution is aided by the low draw weight, enabling greater manual pre-draw to set the hooks on the string. I set mine very short. At this point, the folding stock declares its purpose, enabling the archer to reach over the bow easily. The routine is: Safety off, fold stock, foot in stirrup, hook up the rope and cock the bow, set the (manual) safety on, remove rope, click stock up, check that it’s safe to shoot, slide arrow to string, shoulder bow for rough aim, double check safe to shoot, safety off, perfect aim and loose. The whole cycle benefits from ergonomic design and is rapidly mastered, of course much simpler and quicker in practice than it reads here.
This is a solidly constructed bow and one would want a carrying strap in the field – fittings are standard - but the mass is concentrated at the point of balance under the riser just forward of the trigger. Thus, the felt weight is back on the shoulder and balance is excellent, producing a steady hold. The fore stock is shaped to assist in keeping fingers clear of the string although I discovered the dished contours of the riser, just at the point of balance, lent itself well to the classic European hold, supporting the weapon on the leading hand with elbow tucked in. The safety is within easy reach. The trigger is at least as good as any I have tried and advertised as tow and half pounds. I did not check the figures, but it felt right, very light but still reassuring; not intrusive, yet perfectly predictable. Jim had warned me to approach it positively or it might feel like a two-stage. Well, I must be very positive – one has to remember that Jim thinks in microns – I thought it was absolutely first class; and so has everyone else who had tried it.
Reversal Configuration
Vibration. I suppose there must be some, but I could not detect it. Recoil was not intrusive. The entire shooting cycle of this light-draw crossbow was as smooth as silk and quiet. The only shock was the speed of the arrow. This bow is deceptively fast. Jim reports velocity in his tests from 320 to 370 ft/sec., depending upon arrow weight. Clearly, this is not generated by draw weight – These days 125 pounds is very low for a hunting crossbow – but by a draw stroke which is very long. As best I could measure it, it seemed to be in excess of 19”, accounted for in the reverse draw design and the string coming off the leading edge of the cams, the large diameter of which is explained in the long draw.
I shot initially at ten yards to check the zero on the sight. Off-hand the arrows grouped in a single hole could of inches above the crosshairs. At twenty yards, it was still producing single-hole groups, still maybe an inch and a half above the crosshairs. At thirty-plus, shooting off hand, most shots were single-hole and incredibly still above the center of the crosshair. In this, we are seeing clearly a flat trajectory enabled by a gentle launch and enhanced arrow stability retaining velocity through minimized energy-loss. Over a rest and with the sight zeroed, the results were just as excellent.
Larger cams for a longer draw.
I invited a friend to try shooting off-hand. Now he is enthusiastic, but is completely new to crossbow archery and has not entirely embraced the concept of consistency. At fifteen yards, he shot several arrows in about a three-inch group, from his right shoulder before he remembered that he was left-handed and changed sides. Actually, under the circumstances, which were grossly unfair to Scorpyd that is not bad shooting. He is an indicator of how tolerant is the bow itself. Humor aside, it is relevant to note that while the Scorpyd is without doubt a sophisticated crossbow that one might hesitate to place in the care of the inexperienced, it is certainly forgiving to shoot. In the tests, my bench results with of course no human error component, were flawless one-hole groups; but it was nice to see that results were pretty good offhand, even for a novice, indicating that realizing individual potential is accessible to the archer in this bow.
Had he wished, Jim Kempf might have raised the draw weight for no doubt even higher velocity and I think in future bows he might offer that option. But I think he judged it well returning a very respectable arrow velocity, while retaining the special advantages of this design in flat trajectory and precision accuracy and low stress; after many releases, there was not even a mark on the string center-serving.
At the end of the test, I can see why Jim has worked so long and hard on the Scorpyd that this is in no particle radical design for its own sake. It has nobility of purpose, to create a crossbow, which is quiet, fast, accurate yet pleasant to shoot. The Scorpyd, currently also available in hunting camouflage, is soon to be available with a wood stock, fitted with a crank cocker and with metal components finished in pewter anodize. That sounds nice.
I know Jim already has at least on interested inquiry; how could I possibly not? I hope I will be able to report on the reality very soon.
Now with the technical report completed, I am passing this capable bow into the equally capable hands of my good friend and editor, Daniel Hendricks. He is as fascinated by the Scorpyd as I am and has promised to take it into the field to report on its hunting capabilities. I think he is going to like it and I look forward to reading his report. With thanks to Jim Kempf for allowing me to review a fine bow. For more information go to www.scorpyd.com, email jjk.rdtarchery@hotmail.com or call 319-331-4700.
Photo Captions:
Toye0011 – The Scorpyd looks and IS deadly.
Toye0014 – Stock folds for shorter spanning geometry.
Toye0017 – Good Balance
Toye0019 – The Scorpyd’s Claws
Toye0020 – Reversal Configuration
Toye0024 – Larger cams for a longer draw.
Toye0025 – Well engineered limb pockets.
Toye0027 – View of riser and limb pockets.
Toye0031 – Latch housing and arrow retainer.