Bow Performance Project - JZW Manchu (part 2)
Silent Thunder Ordnance
Lets start off with a huge thank you to Tiger Tail Archery for supplying this bow for assessment. The rumor mill has it that this is the best of the breed, the Manchu replica to rule them all, the benchmark. What better place to start then?
In part 1, we did the force-draw analysis and general impressions. Here the rubber meets the road, and we spit 1111 grain arrows through the chrono with this beast. I want to note quickly that this is one of my favorite bows. While third favorite doesn't sound all that impressive, only beaten by my two birchbark backed Korean bows, it should be. The more I shoot this bow, the more I like it. The hard wearing ray skin accents in particular are an extremely nice touch, which I liked so much I started applying them to other bows.
We used a 1111 grain arrow, yes it really ended up being precisely that, shot repeatedly. This is as opposed to our standard testing set, which is neither long enough nor meets the minimum GPP of this bow.
So how did it do? Do my earlier subjective comments regarding arrow velocity stand up? The short answer seems to be an emphatic YES! At a whopping 18.8 grains per pound, this bow managed a maximum of over 155FPS, which translates to 60 foot pounds of energy. 71% efficiency, particularly for a bow this large and heavy is nothing to sniff at, in spite of the high GPP, but by far the most impressive number is the output energy over poundage; near as makes no difference it is 100%. This is possible due to high early draw weight, a very long draw, and a very flat force-draw curve. If you store 1.4 foot pounds of energy for every pound of draw weight, you only need 71% output/stored efficiency to spit an arrow back out with 1 foot pound of energy for every pound of draw weight.
Perhaps more interesting though is the comparison to other bows. Note that, in terms of poundage, this bow is in 5th place (not counting the Hwarang). Despite that, it has the highest kinetic energy output of any bow we've yet tested and by a reasonably comfortable margin, 9% more than the AF Tatar which is second best and 5 pounds heavier. So there it is, the Manchu bow living up to its name. Hopefully this'll be the first of the breed we test, rather than the last.