Broadheads acting funny

[frassettor]

I shoot a BW PLX longbow 58@28 and am using tapered Hickorys (spined 80-85#) that are cut to 29 inches tipped with a 150 gr Magnus 1. I tried mounting them so they are in line with the string, and also tried the other way as well. I noticed that they are droping to the right and low at the last second. Should I try a different head?, The arrows fly great normally.

[robtattoo]

Sounds daft, but that (in target archery) would be the classic symptom of short drawing your bow.
You could be either creeping slightly (ask me how I know 'bout that one  :rolleyes: ) of are simply 'aware' that you're shooting broadheads & under-drawing sligtly.


Or it could be a tuning issue.

Do you have much offset/helical to your fletching?

[O.L. Adcock]

Broadheads don't cause arrows to fly funny. Poor tuning does. You can't "see" good tuning with field unless they are real bad. Try a heavier head, I assume you are right handed.....O.L.

[frassettor]

Originally posted by robtattoo:
Sounds daft, but that (in target archery) would be the classic symptom of short drawing your bow.
You could be either creeping slightly (ask me how I know 'bout that one   :rolleyes:  ) of are simply 'aware' that you're shooting broadheads & under-drawing sligtly.


Or it could be a tuning issue.

Do you have much offset/helical to your fletching?

Yes, I have a pretty strong helical. Ted at Raptor makes my arrows for my. It looks great till about 3 or so feet to the target then BAM low right. You can actually see it  :eek:

[Robert Honaker]

I don't shoot wood, but IMHO you need to shoot a heavier BH. Maybe 175-200'ish.
Robert

[Dave Bulla]

Do you shoot with your bow vertical or canted?  What is your nock height?

Point of impact to the right usually means underspined for a right handed shooter but lets see....try to follow...

Your bow is 58 pounds so 55-60 spine is the "starting point".  The old rule of thumb is add one spine group for each inch over 28 so that would put you at 60-65 with a 29 inch arrow.  Add another spine group for the heavy head so 65-70.  High performance string? add another one (maybe two) so 70-75 or 75-80.  High performance bow, add one again (or maybe two since it's a widow             ) so that's 75-80 or up to 85-90 depending on if you added one increment or two on the high perf string.  Is your draw actually 28 inches or do you pull the head almost to the back of the bow with your 29" arrow?  If you are pulling closer to 29 than 28 you might have to go up one more group yet or 90-95.  Whew!  we're getting up there eh?

So, maybe you are a tad light on spine.  I'd try two things.  First I'd check the nock hight.  Shooting split finger, the bottom of your string nock should most likely be between 1/2" and 3/4" above the shelf.  I've personally had problems trying to shoot 3/8" nock hight with broadheads and had them dive into the ground at about 20 yards.  Raised the nock and it all went away. Or in a pinch, nock over instead of under just to try it without moving the nock.

Next, if that doesn't help or even if it does help, try cutting a piece of leather like a boot lace and taping it over the side plate directly above the deepest point of the handle and shoot again.  If you are overspined, this should compensate by decreasing the amount of center shot and allowing an underspined arrow to fly properly.

If the nock change fixes things you won't have to change your arrows.  If building out the side plate does the trick, you need to either shorten your arrows as much as you have room for or go to a lighter head unless you don't mind leaving the strike plate built out.  If you are going to leave it built out, get rid of the tape and insert the piece under the existing side plate.  If the strike plate makes it even worse, go the other way and remove the added piece and try a 125 grain head.

[Dave Bulla]

Had any luck yet?

[donw]

i think i'd try a lighter b'head...

[O.L. Adcock]

"So, maybe you are a tad light on spine."

I'm guessing he's over spined and the tail end is hitting the bow/shelf. He'll know going to a lighter head if things don't change or gets worse....O.L.

[Jeff Strubberg]

I'd guess underspined, myself.  BW's are notorious for requiring a lot of spine.  Dunno why.

[George D. Stout]

I think overspined with that setup.  The spine is definitely off or it would not "dive", which means the broadhead wants to take over the arrow.
Black Widows shouldn't require a super heavy spine any more than another bow with the same centershot/draw weight/length and string material.  You could probably drop ten pounds in spine for that setup.

[Jeff Strubberg]

"shouldn't", but living in BW county I can tell you that there are very few widow owners shooting less than 80# spines...

[wingnut]

One thing that I think we all assume is that the head is on straight.  Spin check them and make sure they spin true.

Nothing screws up a good tune like crooked broadheads.

BTW I'm with Jeff, when James was in business he had a chart to match arrow spine to bow.  BW was +18 if I remember correctly.

Mike

[Jeff Strubberg]

One thing that I think we all assume is that the head is on straight. Spin check them and make sure they spin true.

Nothing screws up a good tune like crooked broadheads.

Dangit Mike, it's bad enough having my wife catching me missing the simple stuff....

[longbow1]

You are overspined, a broadhead will show tuning problems right away. Retune your bow, try barshafting.

[Dave Bulla]

Well, looks like I stirred the pot with my underspined theory.....

I still believe it's a possibility (as stated) but like I said above, first thing I'd check is nock hight.

And Mike, I'm with Jeff.  Maybe you heard my hand smacking my forehead a moment ago?

[robtattoo]

I still say he's shortdrawing....