How much speed/distance will I gain?

Joined
Sep 29, 2016
Messages
642
Location
Utah
Hey guys last year I was shooting a 509 grain arrow out of a 70 lb prime rize. I just ordered some 388 grain Easton bowfire arrows just to shoot 3D in the off season. My question is, how much faster do you think I will be dropping 121 grains? I also am using the Garmin Xero sight. It was maxed out with the 509 grain arrow at 79 yards. I am hoping the 388 grain arrow gets me closer to 100. What are your thoughts?


Sent from my iPhone using Tapatalk
 

Gorp2007

WKR
Joined
Dec 4, 2016
Messages
929
Location
Southern Nevada
Once you've got your rough speeds calculated you can throw them in here and see how your drop changes out to 100 yards.


I know for my set-ups going from 286 down to 268 fps means I'm dropping an extra 15 inches at 70 and 28 inches at 100. And that's just by adding 59 grains at 65#. Dropping 121 grains is going to
 

5MilesBack

"DADDY"
Joined
Feb 27, 2012
Messages
15,525
Location
Colorado Springs
For my setups, 1 FPS per 3.5 grains is really close to reality. One bow shoots 500gr arrows at 285fps and 390gr arrows at 315fps. And with that bow set up for the 500gr arrows, I can put my 80 yard pin on the 100 yard target and those 390gr arrows will punch the center of the bullseye.
 

87TT

WKR
Joined
Mar 13, 2019
Messages
3,431
Location
Idaho
I always wondered this but operate under the theory of run what you hunt. I shoot everything the same for every circumstance. Arrows, sights, stabilizer, quiver etc. The only exception is after tuning, I limit broadheads to save the targets. They shoot the same point anyway.
 

nphunter

WKR
Joined
Jul 27, 2016
Messages
1,699
Location
Oregon
I'm really close to 5MB for speed loss, I went from shooting a 395gr arrow to a 496gr arrow and dropped about 25fps - 30fps. What that means in the real world is my pin gaps grew, I went from shooting a 5 pin 30 - 70 yards to 20-60 yards, my pin gaps were very similar just at closer ranges, I did have to drow my 50 & 60 pin and my sight tape was quite a ways off, roughly 10%. Had to dial to 77 to hit at 70, 99 for 90, 110 for 100 roughly, I didn't shoot it like that for long but using 10% got me near the center of the target when dialing before I updated my tape.

Going heavier my 3D scores definitely suffered shooting unmarked yardage, which directly correlates to real-world shots if you have an animal come in that you can't get an accurate range on. I think you will get 100 yards by dropping the weight, honestly though I've only shot a couple of shoots that have any targets past about 70 yards. It is fun to shoot at those distances though.
 
Top