Well I did some playing with the On Target 2 software from pinwheel and a ballistics calculator and discovered a few things. Some I pretty much figured others were interesting.

For one; like Arthur said, drop and percieved trajectory are two different things. Trajectory has to do with how the projectile intersects your line of sight as it goes above it and then drops back into it again. On a rifle or scoped crossbow sight height and sight in range effect this. On a bow the peep height, sight height, sight radius, nock position and distance to the target can effect the percieved trajectory.

I also discovered that the weight of the projectile has little to do with it at these short distances, providing the speed remains constant. Obviously if you use a shorter lighter arrow or bolt out of the same weapon it will give you an increase in speed. But if you compare a bow or crossbows at the same speeds it doesn't matter that one shoots a 350 grn arrow or a 450 grn arrow or bolt. As long as the speeds are the same the trajectory and drop will be the same at short disances. KE will increase with the heavier arrow though.

I figured most crossbows use a scope or short radius sights so I used a ballistics calculator for some of it. I compared it with On Target though to see that I got simular results so it wasn't way off or something. I also used my girlfriends step dad's cheap crossbow with a red dot sight as a referance for sight height and what not. I used 3 inches for the sight height. For the bow comparison I used On Target with a Bowtech black knight shooting 345 fps with a 30 inch draw, a peep sight and a copper john's dead nuts 3-d sight.

This is what I came up with;

With a 30 yard sight in a crossbow would need to shoot around 420 fps to get 3" of drop at 40 yards. However if you sighted in at 40 yards the bolt would be 3" high with a speed of 378 fps. Both of these are much faster than your ordinary crossbow will shoot. The bow was pretty close to that from what I could tell, though you have to do some guessing because On Target won't calculate speeds that high, I think the limit was 375 fps. The bow seemed to have a very slight advantage in percieved trajectory because of the increased sight radius and sight height. Not enough that it would really make any difference though.

Here is the interesting part. If you set the speed to 345 fps and sight in at 35 yards you are 1.8" high at 30 and only 2.6 inches low at 40 with the crossbow. With the bow I got 1.62" high at 30 and 2.39 inches low at 40. And at 20 yards you would be around 3" high. Those are pretty impressive performance results in my opinion. You could easily shoot to 40 yards with one pin if you wanted to for deer sized game, maybe even a bit farther.

Also the On Target software which seems to be fairly accurate when I use it shows the BKII capable of 360+ fps with some minor tweaks to the set up. Like a slightly longer draw, a few more pounds of draw weight and a 350 grn arrow with nothing on the string except for a loop. It's not uncommon to get a bow that is supposed to be 30 inches and 70 lbs to actually be 30.5 inches and 71 or 72 lbs maxed out. There are a few here that own them, I am curious if that is something that could actually be attained in the real world. I haven't heard of anyone shooting those kinds of speeds, but they don't shoot that light of an arrow either.

And I didn't do this to antagonize anyone or prove a point. It is something I have wondered about myself and I was bored. This just inspired me to actually play with it. I figured others would find it interesting as well. And keep in mind this is just using calculators and the such. If I had a chrono I would actually compare a crossbow to a bow at the same speeds just to see. You know, I might actually try it now that I think about it. However they would be much slower speeds because I don't have access to anything that fast. I could prove or dissprove the science behind it though.

I do think for someone little like me a top of the line crossbow could be an advantage in speed and KE. There is no way at my draw length and size I could reach those speeds with any bow. But your average cheap crossbow is not that much better than the bow I currently have. I know the cheap one I bought for her step dad is not even as fast. But it's only a 100lb recurve. And in MI they are only legal during gun season unless you have special permit. But I have much better things to use during shotgun season than a crossbow. That would be challenge out of my blind though. A crossbow at 70 or 80 yards. That's a joke guys, don't freak out on me. Might be fun with a 3-D target though.

Paul