Bareshaft tuning results

[FrankM]

OK, took feathers off of two arrows and here's what I found.

I used 28" 5575's out of my 51# bow with a 27" draw, flipper rest centered. My bow spine is 58 according to Stu.

With 125 gr. points, 70 gr. weights added, they weigh 458 gr. FOC is 20.3%. Dynamic Spine is 75.5 according to Stu. I paper tuned these with a 200 gr. point.

I could get them to group with the fletched shafts with 200 gr. points at 15 yards. According to Stu, the Dynamic Spine is 59.1 (close to bow). Wgt. 533 gr. FOC 24.4%.

Sounds like I need to add 75 grains. What do you think, a big point, or weight and point?

Probably be hunting pig with this arrow.

[Bjorn]

Move back if you can 15 yds is a minimum distance. If your set up is not right you may get surprised by errant flight between 15 and 25 yds. I would go with an STOS BH (145 or 160 gn)and an insert of appropriate weight to get to your goal.

[flatlander37]

I'm with Bjorn.  Move back farther to really see what you're working with, and personally I put more weight in the point, with weighted STOS's up front.  Just my $.02.  Mark

[FrankM]

Initial estimates were to add 100 grains. I added 50. Now, it looks like I need to go back for the other 50. Stu's calculator and the guys in this post and other posts said 100. It's amazing how they're in sync.

This would require me to get about a 150 gr. broadhead to go with the extra 50 gr. weight.

I think I can squeak 20 yards out of my suburban backyard. I'll give it a go tomorrow and see if anything changes.

[FrankM]

I just shot the bow at 17-18 yards. I noticed that the 200 gr. points started to veer to the left. The 250 gr. points still shot like bullets. I also noticed the 200 gr. point arrows fishtailed a bit, while the 250 gr. arrows flew straight. Do you think I should go with adding 250 grains in point and weights? What weight point would sound good?  

P.S. My FOC with 250 gr. pts would be 26.6

[JimB]

Frank,the Woodsman Elite/VPA Terminator from 2Rivers comes in a 250 gr screw in.I've heard nothing but good about these.

Another option with more versatility is to use steel adaptors which come in 75,100,125 grs and then combine the broadhead of your choice to come up with the weight you need.The adaptors have a hollow cavity and you can easily add 12-16 grs of lead shot in there to fine tune the weight.

[Bjorn]

If 200 grains fishtailed and 250 flew straight the answer is 250. 100 gn insert and a 145 gn BH.

[FrankM]

I went to the pro shop and here's what I found out:
    http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=1;t=088071    

He went through a tuning process with me and we found that 175 gr. points made them lasers. He did adjust my nock 1/16" and he worked with my form. All of a sudden, the 200's and 250's became unnecessary. I've been schooled.

Here's what my arrows look like for a 51# draw:
28" Gold Tip XT Hunter 5575, 150 gr. point, 105 grains weight including insert, 9.9 gpp, FOC = 22.9 %, Dynamic Spine = 65.0, Total  weight = 503 gr.

Course I won't mind tweeking them a little later once I'm way more experienced.