Author Topic: speed verses kinetic energy (Read 539 times)

cam69conv · « **on:** August 04, 2004, 08:42:01 AM »

Thought this might be a good topic for discussion... Last year I was having problems with pass throughs. I shoot the Hoyt Vortech with an EC cam..Draw weight is at 70# draw leangth is at 29.5" I was useing the carbon express terminators at 11 grains per inch.... One deer I hit ( from the ground) quarterd away dead in behind the 3rd rib at 13 yrds... Oh yeah 100 gr rocket steelheads... Didnt pass through..It didnt hit the off shoulder.. It stuck through the chest...Now I dont know about you all but this is not very good to me..At 13 yards I could COMPLEATLY pass through with my old recurve... Now this year I switched to the carbon express CX300's 9gr per inch...That put me to 298 per second...I do seem to be getting better penetration on my block target..I am also switching to Rocket's Ultimate steel fixed blades (100 grain still). Now as for the topic...I know there are different opinions about kinetic energy verses speed. Like to hear what Ya'll think on this subject...I never had this problem out of any of my hoyts Including an old Raptor I had..Hell I hit a deer with it dead broadside a few years ago at 40 yards and the arrow went 14 yards after goin through the deer. Useing the rocket steelheads then too..Ive never had a problem out of expandables as long as im not trying an extream angle to a deer..But I chose my shots wisely and dont try those shots no matter what I have on the tip..I only shoot for hi persentage quick kill shots...I hate havin to walk 2 miles trailin a hurt deer.

Crayfish · « **Reply #1 on:** August 05, 2004, 09:32:36 AM »

Actually, a lighter arrow with more speed will result in LESS kinetic energy than a heavier / slower setup (assuming same bow, same draw weight, same everything else). BUT, I don't believe that Kinetic energy is necessarily the most determining factor in penetration. It helps, but isn't everything.

If you've gotten passthru's out of the Steelheads before, then it could have been an arrow flight problem or the deer moved at the shot causing the arrow to wobble as it was trying to go thru. Poor arrow flight is one of the main culprits in poor penetration. Be sure you are perfectly tuned and either arrow/speed setup will give you more than enough penetration.

I've always been a heavy/slow kind of guy, but will be hunting with 395gr PSE Carbon Force arrows at 260fps this year (yes, this is light and fast for ME! :grin: ). I'm shooting a new Martin Cougar Mag at 60lbs / 28" draw. Hopefully they will perform at least as well as the 514gr 2413's I've been using for years. Just getting sick of the rainbow trajectory!

Good luck ... Crayfish

Dalton · « **Reply #2 on:** August 06, 2004, 03:16:33 PM »

I agree with Crayfish. If the bow is improperly tuned you can waste energy the arrow would otherwise impart into the deer. I am also a firm believer in the heavy slow method. I shoot a Reflex Caribou that is not very fast to begin with and I am only pulling 60#, yet every deer I have ever shot has been a complete passthrough. The three keys for me are:

1.)Paper tuning my setup
2.)Shooting a heavy arrow (500-600grs.)
3.)Keep my broadheads razor sharp

cam69conv · « **Reply #3 on:** August 07, 2004, 08:32:21 PM »

#1 Bow shoots bullet holes
#2 I was shooting 396 gpi at 281fps
#3 Broadheads are always sharp

Cant seem to figger it out....Hope the new Carbon express cx300's work...I would hate to wrap dang near 1000 bux around a tree this year

Dalton · « **Reply #4 on:** August 08, 2004, 04:32:00 AM »

Man you have got me stumped here. 13 yards should have been a complete passthrough, especially if you didn't catch the shoulder.

You mentioned that you were switching back to fixed blade heads. I think that is a good idea. They seem to penetrate much better. My only concern is that at 298fps, your arrows may plane. I used to have a Mathews bow that shot nearly 300fps, and could never get it to shoot fixed blades very well. It would shoot Marden Mini Max heads beautifully though. Eventually I gave up on the speed game and went to my old heavy and slow methodology. I guess I got tired of trying to fix something that wasn't broke in the first place.

Happy Hunting. :grin:

cam69conv · « **Reply #5 on:** August 09, 2004, 11:18:52 AM »

Howdy Dalton, Ive tested these Rocket Ultimate Steel out of my bow...Lil buggers fly identical to my field tips..Dont even have to "tune" them to the arrow..They have just a 7/8ths cut diameter but the blade thickness is .036 ...Bacon skinner blades they are called...Seems like it will be a deadly combination this year...If not..Then I will have a fantastic excuse to buy the bowtech Black diamond dual cam...Fastest bow on earth...Figure Ill have the excuse cuzz ma other bow will be in pieces around a tree.lol..Me a temper ...NAAAWWWWWWW...lol