Arrow build question?

[Thomasj1107]

When building an arrow how do you all typically approach it from a hunting standpoint? I’ve used some different calculators and seen different numbers for speed and kinetic energy depending on arrow weight.

Do you care only about kinetic energy?
Do you try to find a balance of speed and kinetic energy?

Some lower grain builds shoot very fast (and flat) and only sacrifice a little bit of kinetic energy, what do you think about that?

Is there a point of diminishing returns when going up on weight with heavier arrows vs speed?

Just would like to see opinions

 

[big44a4]

When building an arrow how do you all typically approach it from a hunting standpoint? I’ve used some different calculators and seen different numbers for speed and kinetic energy depending on arrow weight.

Do you care only about kinetic energy?
Do you try to find a balance of speed and kinetic energy?

Some lower grain builds shoot very fast (and flat) and only sacrifice a little bit of kinetic energy, what do you think about that?

Is there a point of diminishing returns when going up on weight with heavier arrows vs speed?

Just would like to see opinions

Depends on what you are hunting. I use one arrow for everything I will hunt deer to elk. I build for an arrow speed/weight and think about the components I want to use to make the setup as durable as it can be. I usually end up 470-500gr. Right now I’m at 498gr and 288fps.

That said I have several buddies that will shoot a 400-420gr arrow for everything at a short draw length with ZERO issues. Elk, caribou, deer…you name it.

 

[Bump79]

When building an arrow how do you all typically approach it from a hunting standpoint? I’ve used some different calculators and seen different numbers for speed and kinetic energy depending on arrow weight.

Do you care only about kinetic energy?
Do you try to find a balance of speed and kinetic energy?

Some lower grain builds shoot very fast (and flat) and only sacrifice a little bit of kinetic energy, what do you think about that?

Is there a point of diminishing returns when going up on weight with heavier arrows vs speed?

Just would like to see opinions

I love this subject. The reality is with everything in arrow building there is a tradeoff taking place. The odds are is the middle ground is where it's at. It really starts with questions in my mind:
1) What is your max range?
2) How good are your at judging range?
3) What is your target?

I recommend getting to 400 grains minimum for durability and max 295 fps for broadhead flight forgiveness. If your shooting at a feeder at 17 yards then shoot heavy or whatever you like. If your shooting out to 35+ then you need forgiveness in location.

A heavier arrow on average will be more durable, penetrate better and be quieter.

A faster arrow will get to the target sooner reducing animal movement, have a more forgiving range error, have a smaller trajectory curve.

The whole "plan b" montra doesn't make much sense for heavy arrows. What is above and below the vital v is bone. If you have more range error you might hit bone you never would have with the lighter one. If the animal ducks and you hit shoulder you wouldn't have given it less time. It's a self fulling procephcy.

The benefits of a faster arrow to me are well worth it. Pick your broadhead for penetration - not the total arrow weight. I call it a normal weight as it's 400-480 grains generally.

 

[Flatmat]

Some solid advice here!

 

[Mighty Mouse]

Ignore kinetic energy. Once you pick your bow and set your draw weight and draw length, your KE is effectively fixed*.

Arrow weight vs. speed is a continuous trade-off between the flatter trajectory of a lighter/faster arrow vs. the greater penetration potential of a heavier/slower arrow. There's no definitive right answer, but IMO 6-7 gpp (grains of arrow weight per pound of draw weight) generally yields a good balance of weight and speed for a hunting arrow out of a modern compound. At 70# DW, a 6-7 gpp arrow would weigh 420-490 gr and fly around 270-290 fps out of a 340 IBO bow at 28" DL.

*KE does increase slightly as arrow weight increases (due to more efficient energy transfer from the bow to the arrow), but the magnitude of the increase is not large enough to warrant consideration when choosing an arrow weight.

 

[sndmn11]

250-300fps, 260-270 is a pretty good spot for ease of tuning and pin gaps.

 

[Dennis]

My opinion, is follow the Dr Ed Ashby Studies on arrow building based on lethality on game animals. You can find the information you seek at https://www.ashbybowhunting.org/ under reports. After 60 plus years of bowhunting I have tried almost every combination of arrow setup (light, moderate and heavy). I've tried tons of broadhead combinations and ignored the Ashby Studies because rumor was it didn't matter because I was a modern compound shooter. The Ashby Foundation continues to study arrow lethality which includes trajectory, momentum, energy, etc. Yes I gave up some trajectory and arrow speed, but I increased my harvest rate and overall bowhunter satisfaction. PM if you have additional questions.
Good luck.

 

[butcherboy]

I like a mid weight arrow to possibly leaning to a touch heavy. Gives me a good trajectory still and the benefit of a little weight. I choose an arrow that’s at least 9 grains per inch and then add weight up front with broadhead and insert. Doesn’t take much up front when the overall arrow is heavier. My current set up is an Easton FMJ 340 cut to 27”. 100 grain broadhead and 50 grain hit. Regular knock with 3 blazer vanes. TAW is 482 grains. Seven years ago I was shooting an arrow that was 7 grains per inch with 200 grains upfront. Killed an elk but the arrow didn’t go all the way through. No bone was hit. This year I blew right through no problem with the exact same shot but had dropped the taw by 50 grains.

 

[Bump79]

Arrow weight vs. speed is a continuous trade-off between the flatter trajectory of a lighter/faster arrow vs. the greater penetration potential of a heavier/slower arrow. There's no definitive right answer

This ^^^^ the only thing you can do is find balance.

 

[doc holiday13]

A few variables but its draw length dependent. In my case, i'd like to stay in the 280-290 fps range. There are very lightweight arrows now so I can play a little bit with the FOC game. You'll want to be in the 10-15% range. Less than 10% and you're arrow can be a little unstable; more than 15% you're killing your speed unnessarily.

With a 31" draw at 80#, 540g arrows at 295. I could probably add a touch of weight up front to get me up to 15% foc but I played that game long enough to know my arrows are more than enough.

I'm tempted to actually drop to a 60# bow and 450ish grain arrow. it would probably put me at at 280 fps which is pretty great and make the bow very comfortable to shoot

 

[Bump79]

My opinion, is follow the Dr Ed Ashby Studies on arrow building based on lethality on game animals. You can find the information you seek at https://www.ashbybowhunting.org/ under reports. After 60 plus years of bowhunting I have tried almost every combination of arrow setup (light, moderate and heavy). I've tried tons of broadhead combinations and ignored the Ashby Studies because rumor was it didn't matter because I was a modern compound shooter. The Ashby Foundation continues to study arrow lethality which includes trajectory, momentum, energy, etc. Yes I gave up some trajectory and arrow speed, but I increased my harvest rate and overall bowhunter satisfaction. PM if you have additional questions.
Good luck.

We've gone back and forth on this one before. To each their own and I have much, much more limited experience but my objection is that Ashby Fdn is not studying lethality and definitely not trajectory. They say use "the heaviest arrow with a trajectory YOU find acceptable" then some of them are constantly saying that the downsides of trajectory and time in flight aren't factors you should weigh into your setup and it's essentially irrelevant. Which is as in denial as the guy who shoots a 375 grain arrow with a 3 blade 2" cut mechanical at 305 fps and says it's the best setup for everyone. Physics is real, it cuts both ways and everyone's needs are different.

Normal weight arrows like @Mighty Mouse pointed out balance out the factors really well. If you're concerned about penetration shoot a well designed extremely sharp cut on contact broadhead. That's where you'll get the best bang for your buck even according to the Ashby Fdn and the downsides are next to none. Say a Iron Will SB 100 grain head on a durable 5mm shaft, upgraded components, 15%ish FOC and a total arrow weight in the 400-500 grains going 265-295 fps depending on the archers setup. There's extremely few downsides to that setup.

Ashby Fdn are studying penetration - on dead game exclusively. Which is valuable but there's controlled variables in their testing. Dead animals have a known range. Dead animals don't move. You have all the time in the world to get your form and there's zero pressure. You've got a perfectly clear line of sight to the dead target. You got all day to pick your shot. They perform the same testing procedures and get the same results, which isn't surprising. It's relevant but it's no where near the gold standard it's presented as. The reality is that a heavy arrow could actually make you hit bone you could have avoided with the lighter arrow due to added range error. Or it could put you in the guts that the normal arrow hit liver due to giving the animal more time to move. Etc.

Again, my point is that it's valuable information but it's extremely narrow testing. They have not done any studies that show that their setups have any more lethality across hunters. Meaning studies across hunters platforms as to who has the highest harvest rate. Some studies that have done this actually show mechanicals are better. I'm not saying they are - it just needs repeated. Watching some of the popular guys like THP who shoot these heavy setups, I'm not at all taking away with the conclusion that their setups are more lethal. They call the dogs all the time for shots too far back, high, low, etc.

I've put together polls and asked the question - when shooting mechanicals how often do you get a pass through? The vast majority of respondents said they most often or always get a pass through. So while these "fail" videos are great - if a 2" cut energy sucking mechanical most often or always gets a pass through... then why are we talking about penetration? There's not this epidemic of penetration issues like is presented by the Ashby Fdn. Heck, most guys I know still shoot Rage for whitetails and LOVE them. I still think the design is subpar but hey there's a lot of guys who swear by them.

I've tested enough broadheads and arrow setups now to be 100% convinced that heavy arrows and unvented long broadheads are not for me whatsoever. I'm happy your having success with them but I couldn't even get to the field with them as my confidence was so low. My accuracy in hunting conditions just isn't there and no amount of tuning gets me to where I want to be. Forgiveness is what I'm looking for.