Mathews Halon 32 at only 285 FPS?

[Spark352]

Had the chance to shoot my bow through a buddy's chrono this weekend. I'm shooting a Mathews Halon 32 (6) 70lbs at a 28" draw length. Arrows weigh in at 405gr. The mods appear to be 27" 85% to my best knowledge. The chrono was reading 285 FPS on average. Does that seem about right? Seems to be a little slow for a fairly modest arrow weight. Any thoughts or inputs?

 

[OR Archer]

If you have 27” mods why are you thinking it’s a 28” draw?
If the bow has 27” mods on it 285 would be about the correct speed for that weight of arrow. What speed do you think it should be?

 

[Mighty Mouse]

Seems about right. Advertised IBO speed of the Halon 6 with 85% mods is 343 fps. Using a rule of thumb of 10 fps loss per inch of draw length under 30", I would expect ≈313 fps at 27"/70# with a 350 gn arrow. Assuming KE remains constant (at 76.2 ft-lbs) as arrow weight increases and solving for speed at 405 gn yields 291 fps, which isn't too far off what your chrono is saying. The 6 fps difference could be chalked up to a combination of estimation error, chrono error, actual draw weight possibly being a little less than 70# due to cable stretch, and the extra string weight of a peep, D-loop, silencer(s), etc (IBO speeds are measured with a bare string).

 

[BazookaJoe]

I've got a 32-6 with 28.5" mods at 85% Letoff and 71# draw weight (just what it came out to when fully tuned). I shoot a 450gr arrow and have gotten 289fps - average speed from 5 shots through a shop's chronograph.

*For reference, I have a peep, speed nocks, and two monkey tails on the strings.

 

[kcm2]

"Only" 285 fps? Good grief.

 

[Spark352]

Thanks guys, seems like the bow may be a little slower than average but not by much. I appreciate the input

 

[Zac]

You should be very happy with that speed and arrow weight. Perfect for fixed blades, I wouldn't want to shoot any faster than that.

 

[Spark352]

Gotcha. Thanks for the insight. I looked at the bow and it’s actually a 28” mod. My mistake. Switching to fixed blades this year so that’s good to know.

 

[Scorpion]

I’d check it with another chronograph, most Halons I’ve seen shoot faster than the average bear. 285 FPS is no slouch, regardless.