Need BH grain size advise for deer/hog

sigfla · 09-19-2006, 04:40 PM

My new Easton 340 spine arrows aren't getting here until next week minimum. My hunting partner was wanting to shoot today so I decided to quickly pick up some arrows since all I had on hand was 3 BH tipped arrows from last year. My bow is tuned for those but I figured I would have my new arrows by this weekend for our planned hunt.

A quick trip around town and no 340's were to be had. A call to my shop confirmed my new 340's wouldn't be here by this weekend. Well I had 3 tuned arrows for the hunt which are shooting very well. I have been practicing this summer with some slightly too long 340's I had on hand. Those arrows are also at the shop getting re-cut and inserts installed and won't be ready by this weekend.

Well I found some Gold tip arrow's at the last store I tried in 400 spine and bought them thinking they were 340's. I later realized they were 400's. My bow is a Bowtech Extreme 60#, shooting 30' arrows. Gold tip rates my bow as ok with the 400's and my setup using 85 grain heads. These are lighter than I would prefer to use.

HOWEVER, having installed 90 grain field points the bow is awesome. My arrows buried almost to the fletch in my block target at 20 yards and my flight was the best it has ever been. Given the depth of impact I have to assume my KE is high, or at least my flight tune is on. My bow also seemed quiter. I know some states only allow 100 grain BH's or higher but Fl. to my knowledge doesn't specify grain weight just cutting diameter.

WOULD a 90 grain muzzy 4 blade BH with a 1 inch cutting circle be ok? I haven't yet tried the 90 grain BH's to see if they will fly well. Worst case I can use my 3 tuned arrows I already have for this weekend. However, with such good flight I am tempted to stay with the 400's and use the 90 grain heads. I have great confidence in the setup as far as accuracy but I want a clean kill also.

sigfla · 09-19-2006, 04:43 PM

FYI since the Gold tip chart recommended the 90 grain head that is all I used today. I could try a 100 if a 90 isn't gonna cut it kill wise for deer/hog.

Hmmm, just checked the chart on my box and huntersfriend.com. Both list the 400 spine 5575 as the arrow to go with my draw weight and arrow length. Gold tip's online chart says I need the 340 spine (7595?). Well I guess I will just try both heads tomorrow and see which fly's the best. I hope my Easton 340's I am getting next week fly this well.

FLOutlander · 09-19-2006, 07:04 PM

Any broadhead with at least a 7/8 inch cutting diameter will do the job for deer and hog in florida. 75 grain, 90 grain...100 grain...it all boils down to Kinetic Energy. Considder the weight of your arrow and the speed at which it travels. Pretty much any compound bow pulling 50# or more, shooting the arrows you mentioned tipped with a sharp broadhead will kill deer and hogs. If your arrows are flying as well as you say they are, I'd leave things as is. You seem to have plenty of power. Good Luck on your hunt!

sigfla · 09-20-2006, 07:18 AM

Thanks for the info.

Chupacabras · 09-20-2006, 07:28 AM

What is the foc on your arrows with sub 100 grain heads?

sigfla · 09-20-2006, 09:46 AM

9.4 % according to Gold Tips program. I have been confused by Gold tips charts. The 3 versions I have seen are all different. With one saying I need a 340 arrow and another saying I need a 400. I believe now I am correctly spined with the 400 in this brand of arrow. I should be able to use any head I like so I will test them both and see which flys better.

sigfla · 09-20-2006, 11:55 AM

Well just shot a few arrows over lunch. The 90's flew great and my groups were tight as can be at 35 yds (my max distance in the yard). My field points were a good bit higher than the broadheads. I have a D-loop on my Bowtech Extreme and I don't really want to fiddle with it. I am going to increase my lower limb poundage a bit and see if that brings my knock point down enough to even things out. The more I use the walkback method the more I have confidence in the bow and its tune.

All of my 20 and 35 yd groups were dead in line with my 15 yd grouping. If it wasn't for my broadheads nose diving it would have been perfect. I love these Gold tip's and Muzzy 90's. They are a bit noisy out of my WB but I will fix that also. After reading here I assume 1/4 adjustments at a time to the tiller are all I want to go, right? Shouldn't bother my cam timing any right?

Rob/PA Bowyer · 09-20-2006, 07:00 PM

Just a side note, not that you thought your KE changed I wanted to note that it didn't. Whatever your KE was before switching arrows, your KE remained the same after switching arrows. Unless you take extremes in arrow weight the KE won't change. When you decrease arrow weight, the arrow speed increases, the KE remains, if you increase arrow weight, you decrease arrow speed, the KE remains the same.

Penetration is influenced by so much more take for instance, field tip design. I bury my ACC's almost everything I shoot them into at all but 80ftlbs of KE. If I simply go to a different field tip, the arrow doesn't penetrate nearly as far.

That's just one example.

sigfla · 09-20-2006, 07:52 PM

Well just got back from a session. I increased my lower limb poundage and brought my BH arrows up a bit. They still hit low. Since Chupa asked about my FOC calculation with 90 grain heads I did some quick reading on the subject. I think maybe my nose diving BH's may be due to the tip weight being so low. My quick research seemed to indicate the nock may be moving a bit faster than the tip and causing a dive due to the FOC calculation. I think a 100 or 125 grain head would bring the FOC figure up to the 10-12% suggested by reading as ideal for BH flight.

I will give it a try tomorrow morning and see. As you can tell I am a constant tinkerer. If it isn't perfect it just drives me nuts. Good hobby to get into, huh?