I have been playing with some muzzy 115grn four blade broad heads. they group right with my feild points 100grn with very little adjustment. Now that I have them both hitting the same spot the field points are still grouping good (5arrows 21/2in circle at 20 yrd) but they are fishtailing slightly, should I just leave well enough alone, or is a sign of some tuning issue that I'm just not seeing?

I don't think they should be fishtailing. I know that my arrows look the same whether I am shooting broadheads or field points. I would try shooting @ 30 yards, and see what is going on there.
Was it calm when you were shooting? If you get a little bit of crosswind, the arrows will fishtail a bit, even when they are tuned well.

Avoid the inevitable until it is absolutely unavoidable!

it was indoors. dont have 30 yrds there will have to wait for a less windy day to try 30 yards in the back yard.

Bo
Whenever I get fishtailing or poor arrow flight, I paper tune my bow to get things back in order and then, resight my bow. Regardless of how tight your groups are the poor arrow flight you are getting will definitely affect penetration.


TB

I shot the exact same broadheads this weekend. I compared the 90grn 4 blade to the 115grn 4 blade. At 30 yds, the broadheds shot an amazing group. Ruining 3 out of 6 brand new 3-49 ACC arrows. Anyway, I noticed that the alignment has to be just about perfect otherwise I can get a slight fishtail. Just in the begining and then it cleans up. If you were to go back further, it would still group given the fact that it has more time to recover. I would check nock alignment and then shoot thru paper as suggested. You may have more than one culprit. But I know these broadheads can fly my groups no kidding were at 30 yds, 6 arrows all touching and sliced carbon off of 3 out of the six. I did this test on purpose and now have to purchase new shafts. I needed to know if I was going to be using the 90's or the 115's this season.

Good luck!

You can group shoot without wrecking arrows, it is just a long walk!

Or multiple spots!

<img src=icon_smile_wink.gif border=0 align=middle>

Avoid the inevitable until it is absolutely unavoidable!

I dont notice the fishtailing with the muzzy's only the field points three are straight into the target two are leaning slightly to the left. I have spun all the arrows and they are fine. I will re tune wed and try it all agian. thanx for the suggestions!

Have you tried 115 gr. field points? Could be a FOS thing that the tune is better with the 115 gr. points. Just a thought.

Winger