Minimum fps for plains game

[chiefdale]

thinking of getting the grissly stik 650 grain set up for hunt.most threads talk about heavy arrow ,foc etc. my question is what would be the minimum fps for 20 to 30 yard shots for plains game with heavy arrow set up so dont end up spine shooting animal.

 

[BRICKBURN]

"Jumping the string" is something to keep in mind for certain.
You can end up shooting high even with the fastest bow.

Most are so obsessed with "faster" I am not sure that anyone has ever tried to get near the lower limits.

 

[BRICKBURN]

One difference between game in North America and African species hunted out of a blind is the "education' factor.
When do we shoot at a deer in a herd?
Plenty of jurisdiction don't allow baiting, so there is much less possibility that a herd will be educated by the repeated sound of a bow and arrow being shot.
This is not the case in many places in Southern Africa, certainly on game farms that are heavily hunted over bait or water.

Does that mean the plains game in Southern Africa are more likely to jump the string? Likely.
*note the grand generalization.

An older (2010) article on the subject:

"I recently performed a mathematical study to determine how far a deer can drop between the time it hears the shot and the arrival of the arrow. Of course, a faster arrow gets to the deer sooner so the deer doesn’t drop as far. This is especially important, in my opinion, on shots from 25 to 35 yards. At this distance, the deer is close enough to hear even a quiet bow, yet it is far enough that it can drop a good distance.


I had to make a few assumptions to come up with final numbers. For example, I estimated that it takes a deer .15 second to begin moving after the bow fires. This includes the time it takes for sound to reach the deer when it is 30 yards away. My estimate is based on the number of frames from the video we counted from the bow firing until the bucks started to drop.


Using this approach, I determined that, at 30 yards from a treestand, a deer can drop roughly 14.8 inches by the time an arrow moving at 260 fps gets to it. A deer may even begin to turn slightly by the time the arrow makes it there. Now if you speed up the arrow to 300 fps, the deer will drop roughly 8.8 inches by the time the arrow gets there. That’s a 6-inch difference, a very important improvement.

Both are important, but given the choice, I’ll take the fast arrow over the quiet bow every time. For that reason, I think the best setup is a fast arrow (one that weighs about 6 grains per pound of draw force) from the quietest bow you can find. Speed takes priority in this situation.

Aim increasingly low on any shot past 20 yards. In my opinion, shots past 30 yards at alert game are too sketchy to justify with a bow and arrow. Game is quicker than you think. If you don’t read and adjust to this alert state correctly, you are going to miss critical opportunities."

https://www.americanhunter.org/articles/2010/7/14/the-science-of-string-jumping/

 

[chiefdale]

thanks brickburn excellent article for reference and discussion.

 

[firehuntfish]

Using this approach, I determined that, at 30 yards from a treestand, a deer can drop roughly 14.8 inches by the time an arrow moving at 260 fps gets to it. A deer may even begin to turn slightly by the time the arrow makes it there. Now if you speed up the arrow to 300 fps, the deer will drop roughly 8.8 inches by the time the arrow gets there. That’s a 6-inch difference, a very important improvement.

Both are important, but given the choice, I’ll take the fast arrow over the quiet bow every time. For that reason, I think the best setup is a fast arrow (one that weighs about 6 grains per pound of draw force) from the quietest bow you can find. Speed takes priority in this situation.

I will not dispute the speed/drop statistics, as they seem reasonable enough. I will also add that anyone who has bow hunted hard pressured whitetails can tell you that they are possibly the most "string jumpy" critter on the planet. I would agree that arrow speed is a huge component with that species. I have had more than one whitetail duck my arrow over the years..... I will also say that a great deal of what we used to believe about arrow weight, speed, FOC, KE, momentum, etc,. has changed considerably since 2010. The science of it hasn't changed, just our understanding of it...

Here's where I tend to disagree with the speed argument to some extent as it applies to African game.... Whitetails are what I would consider to be on the smaller side compared to most African plainsgame animals. You can get away with a lighter, faster arrow with less momentum and still get good enough if not great penetration. I could make the same argument for pronghorn and even mule deer. However, I think we need to introduce elk and moose in to the conversation when honestly comparing body mass and density to most African plainsgame. With animals of this size, the importance of penetration supersedes speed in my opinion.

The same bow hunter that may very successfully put a light, fast arrow completely through a bushbuck, impala, or blesbok will also likely have other species like kudu, zebra, gemsbok, wildebeest, etc,. on the wish list. I would not recommend that same light arrow for these species. It won't get anywhere near the penetration needed, and this will result in wounded or lost animals at some point. I have seen it played out too many times to count.... For the handful of African plainsgame species that tend to be string jumpy, I caution hunters to take smart shots. Unless you are planning to do lots of spot & stalking, there is no need to take shots beyond 35 yards in all reality, 20 yards and even less is the norm for most hunters that will be doing the majority of their hunting from hides.

The key to success on African plainsgame is to find the balance between speed and momentum. That is why I strongly recommend a total arrow weight approaching or exceeding 500 grains with at least a 20% FOC. This allows plenty of speed for most hunters shooting bows from 50 lbs. and up, and the increased FOC will provide the critical penetration. Even with the lighter arrows, you can still expect significant gains is penetration simply by increasing the FOC if nothing else. And, it goes without saying, I recommend avoiding expandable broadheads at all costs. They are "momentum robbing parachutes" attached to the end of your arrow shaft. I know that is a controversial opinion, and I don't care to debate it with those hunters who have gone to Africa and successfully killed animals with expandables. It's merely my opinion based on my experiences that I have witnessed first-hand. There are many more dependable choices, and I will leave it at that.

 

[kathy]

I agree with Dan.
I want a quite bow, an arrow at least 600 grains and razor sharp cut on contact broadhead (175grain VPA solid) .
Don't shoot alert nervous animals ,let them calm down, broadside or quartering away looking the other way they will not jump the string. If the animal is looking towards you most likely will jump the string.
I don't no the minimum FPS for planes game, my last trip I was shooting 615 grain arrows @ 220 FPS, complete pass thru on 14 animals, 1 blue wildebeest had arrow just hanging by fletching on off hand side.
I tried grizzly sticks and didn't like them, none would spin true, dam slow, expensive. Forrest

 

[BRICKBURN]

Forrest, what #'s were you pulling and what distances? Just for information.

 

[BRICKBURN]

......
Here's where I tend to disagree with the speed argument to some extent as it applies to African game.... Whitetails are what I would consider to be on the smaller side compared to most African plainsgame animals. You can get away with a lighter, faster arrow with less momentum and still get good enough if not great penetration. I could make the same argument for pronghorn and even mule deer. However, I think we need to introduce elk and moose in to the conversation when honestly comparing body mass and density to most African plainsgame. With animals of this size, the importance of penetration supersedes speed in my opinion.

Any heavily hunted herd critter will become twitchy, no matter where they live.
I agree, there certainly needs to be a balance as you suggested.
String jumping is certainly not the only consideration.

That's those little Whitetails they grow down south.

 

[gpelkhunter]

I am shooting a 435 grain arrow at 295 feet per second out of a 66 lb Bowtech Destroyer. Did a trip to Namibia in 2015. I had a couple of animals move just as I shot and still managed to get to the kill zone. If doing plains game, IMHO its best to have a faster arrow to hit the sweet spot of the animal.
For broadheads I shot most with a fixed, DRT, big 2 blade with bleeders, had pass thrus on my eland, wildebesst, and springbuck and and on all animals I had a great penetration with quick recoveries.
my old setup had a 375 grain broadhead doing 305 feet per second and I had numerous pass thrus on elk and moose here in Alberta, Canada. Shot placement is the key and getting to that spot the quickest is my advice.

 

[firehuntfish]

That's those little Whitetails they grow down south.

I will concede that your Canadian whitetails and muleys are monsters compared to our southern deer! I would classify them right there with elk and moose as the North American game most comparable in body and mass to the average plainsgame animal. And, I would not use a light fast arrow on them either... To your point that all animals can be twitchy, I would argue that a nervous animal is not the same concern as an animal like a whitetail that is specifically capable of flexing its front quarters and ducking 14-16" at the sound of the shot. Lots of African plainsgame move at the shot, but very few are capable of that drastic lunge that a whitetail is so famous for... If you watch most African game, they tend to turn away from the sound more so than duck from it.

I could not agree more that near perfect shot placement on African or any game for that matter is crucial to quick, ethical bow kills. It's been said many times on many hunting forums that you can kill any animal on the planet with a field point placed perfectly.... Arrow design and broadhead choice are for all of those less than perfect shots that we all make from time to time. Deep penetration takes up the slack for lots of marginal shots.

I'm forming my opinions based off of what I have seen in the field on hundreds of African animals both recovered and lost with archery equipment.... I'm not opining on what I think to be true or what an online calculator says..... I had to learn through experience myself. On my fist safari both my wife and myself were set up with light, fast arrows that have worked well for may years on whitetails, hogs, etc.... I got away with better overall performance only because I shoot 70lbs. @ 29". My wife had poor penetration results even on well placed shots. Upon our return home, I experimented with heavier arrows with big FOC's and the difference in penetration was night an day for both set ups. The loss of arrow speed/trajectory was actually pretty marginal. As I mentioned in another thread, my wife is now shooting 52lbs. with a TOW of 650 grains, and blowing right through everything she shoots. The two largest animals she killed last trip were a kudu and gemsbok, and both arrows were stuck half way up the broadhead into tree trunks after passing through.
In fact, from the results that I have witnessed over and over again, the lighter the draw weight you shoot, the heavier the arrow/FOC should be... Momentum needs to be maximized on lighter poundage set ups.

Nothing can spoil the mood of a great safari like the need to stop the hunt to track a wounded animal.... Or worse yet, loosing the animal altogether. ... I only offer my advice in hopes to spare some bow hunters from those feelings.

 

[Ryan]

With that heavy of an arrow your bow should be pretty quiet. Plus you'll probably be shooting out of a blind which will also reduce noise that the animal hears so I wouldn't worry about string jumping from noise. Yes the animals are twitchy but it can happen or not happen at any speed. There really isn't a low side speed to worry about. Most traditional shooters are shooting in the lower 200's and putting arrow in the kill zone, same can be said of compound bows in the 80's when I started shooting.

 

[jeff]

I got exit wounds on waterbuck, and kudu with 178 fps and 565 grain arrows. My wife with a 25.5 draw and #50 at 200 fps with 480 grain arrows got complete pass throughs on zebra, kudu, all were shot using a smaller CC broadhead. From what I see zebra, kudu, ect. don't have as thick of hides as elk and moose.

 

[kathy]

Brick, I was shooting Elite Answer 60lbs @29 1/2" draw, Easton 20/20 alum 6"wrap ,( 3) 4" parabolic feathers VPA 175 grain solid . Still shoot the same set up for everything here in U.S.
I shot 80lbs for years ,on my first trip to Africa I tor my rotator cuff and have shot 60 to 62 pounds every since, that was in 2010 Forrest

 

[BRICKBURN]

Brick, I was shooting Elite Answer 60lbs @29 1/2" draw, Easton 20/20 alum 6"wrap ,( 3) 4" parabolic feathers VPA 175 grain solid . Still shoot the same set up for everything here in U.S.
I shot 80lbs for years ,on my first trip to Africa I tor my rotator cuff and have shot 60 to 62 pounds every since, that was in 2010 Forrest

What distances to game?

 

[BRICKBURN]

.................... I would argue that a nervous animal is not the same concern as an animal like a whitetail that is specifically capable of flexing its front quarters and ducking 14-16" at the sound of the shot ........................

I want you to share some video of these Whitetails you have trained.

 

[firehuntfish]

I want you to share some video of these Whitetails you have trained.

You were the one who posted the article with the statistics on whitetail drop. I merely agreed......

YouTube has dozens of videos exemplifying this for anyone that is interested... Here are two decent examples that show the drop distance with animation in slow motion.

 

[lpace]

This was at 28 yards, 250+'ish fps.

Impala are oh so QUICK!

• lpace
• Aug 16, 2016

This impala was totally unaware of our presence. 27 yard shot, 260 fps arrow speed (not a flame...

The above video was at the end of a cull hunt in Namibia. I took about 10 impala on that hunt (man, that was a fun hunt). One significant difference in observed string jump was how relaxed the animal was at the shot. The impala in the video was alone (not the best scenario for twitchy critters), the frickin' thing ducked a country mile...

I don't know what the minimum velocity of an arrow is to not have an animal duck an arrow, but it would have to be fast. I would say to minimize string jump, if blind hunting - give the animal time to relax at the water hole (bad things happen at water holes, those African animals are wide awake at water), keep the shot distances short, a quiet, quiet, quiet bow (a heavy Grizzly Stick arrow would help in that department), quiet arrow in flight as well (some fletching and broad heads are quieter than others).

 

[BRICKBURN]

You were the one who posted the article with the statistics on whitetail drop. I merely agreed......

.....

I was not questioning the assertion. Just wanted to see some of your experiences. I hoped you might have some video.

By the way, thanks for the videos. Interesting stuff

 

[BRICKBURN]

That Impala video is what I always imagine them doing. It is striking similar to those whitetails at the feeder.

Thanks for sharing guys.

 

[kathy]

Brick, sorry left out shot distance, 17 to 22yards.
I was whitetail hunting on the ground, a deer came from my left going to my right, 20 yard broadside shot. I stopped the deer was already drawn, when I saw the arrow hit is was way back (liver hit) ,not much penetration , very unusual for my set up.
got out and looked for blood, the ground was covered with blood. went got my dog and tracked the deer, the broadside deer had spun on the shot and shot thru the deer nose and then into the liver ,hard to believe but true. Forrest