MGH_PA

Well I had posted earlier about my bow shooting erratically with broadheads on (68lbs, 30", 30" 2217 Eastons XX75s w 100gr broadheads). I was told the spine was way too weak, so I went with some Easton 2413s with the same 100gr broadheads. Well my broadheads are still all over the place. I know it needs tuned because of the change of arrows, but I should still be getting groups should I not? I know I read that it's necessary to have a helical or offset with fix blade broadheads to help the spin, but I can't because I have a simple two prong rest, and any type of helical or offset will cause fletch contact. So, I also noticed the blades of the broadheads don't match the fletching as well, and I have heard this causing the arrows to fly erratically. Where do I even begin with this mess?

DaveC

How big are the 100 grain heads you are trying to shoot?

I had good results with muzzy 100's & straight fletch the one & only time I tried to steer a BH with straight fletched arrows.

The other issue I see is you changed arrow diameter which would now place your arrow higher in the rest than it used to sit. That may be a moot point as I haven't fooled with aluminums in quiet a while.

Have you achieved decent groups with field points yet?

JOE PA

Matt: With 2413 and a prong rest, you have plenty of room between your prongs of the rest to use at least offset fletching, if not helical. Since you switched from 2117 to 2413, as Dave said, your arrow diameter is larger, you should lower your rest some, or adjust the prongs to give more gap between the prongs. That will also allow the arrow to sit a little lower and more securely for a hunting situation. I would think currently just switching arrows, your nock pt. is probably too low for these new arrows and the old rest height. Do the broadheads tend to shoot in any particular direction compared to the field points? If they are just erratic, then it could be broadhead aligment with the shaft. I know many people claim that lining the fletching up with the broadhead blades makes a difference, but I've never found it to be very important with most bows. I remember aligning the one broadhead blade straight up when I used to shoot older single cams that had horrible nock travel, but I pay no attention to it at all now, and broadheads fly nicely out to 40 yards. Have you tried paper tuning the bow? It is hard to figure out what the problem is, but time to get it straightened out.

slee

I would agree with Joe, you should have plenty of room between the forks to get at least offset fletching. I also haven't found any need to align broadhead blades with fletching. How can you align a 4 or 2 blade head with 3 vanes? I would go back to the basics. Paper tune it, then start trying to get FP and BH shooting the same using the "walk back" method. I'd also give the bow a thorough inspection for string problems, worn cambearings, etc that might explain the irratic flight. Also, have someone watch you shoot if possible to make sure it's not shooter malfunction. We are all prone to that from time to time. It sounds like you need to start from scratch and see if you can get it solved.

Rob/PA Bowyer

Also, there is no need to align the blades/fletch...I've never done this and like above, with Muzzy's had pinpoint percision.

I didn't notice anyone mention tuning your arrows to make sure there is no broadhead wobble. Misalignment with your inserts/broadheads will cause the broadheads to plane differently. That is why your probably not getting groups as well as a mistuned bow. The blades of a broadhead will steer the arrow. If the arrows are coming off the bow oddly, the broadheads will steer the arrow all over the place.

It's really not rocket science, well sorta but if the bow is tuned, the arrow is tuned, the broadheads will group. Perhaps not exact POI as field points but either a minor sight adjustment, or minor rest adjustment and your ready to go hunting with broadheads.

I also recommend at least a slight offset as mentioned above too. With 2413's and a prong/shoot through rest, you should have ample spreadage to use an offset.

ijimmy

Why would you buy new arrows , without checking what spine arrow to get ?
You are still underspined .

here are some close arrows
2415
2219
acc360

slee

He is actually "close" with his 2413s. If he has to drop draw weight a few pounds, he'll be fine. That's assuming he needs to. They may fly just fine. There are more variables involved than a shaft selection chart can cover.

MGH_PA

I did check, that was also a size recommended by several people. I'm slowly getting these grouped better now that I have them fletched slightly offset. I need to play with some things, but I'm getting it. I'm very new to all of the tuning issues. The pro shop I go to has all but shut down their business, so I'm left to do most of this on my own, or Gander Mountain, whom I really don't have a lot of faith in. Not sure if that's justified, I'm sure Rob would know.

DaveC

If you find yourself not getting very far on your ownI would call Gander mnt.and ask who their most experienced bow tech on staff is and then ask when he will be in next (shift). Try to catch him when they are'nt so busy and hope he/she is a nice person. Maybe they could lead you in the right direction.

ijimmy

Sorry if I came off snotty sounding , you are still way underspined , and I know the kind of fits that has given myself and others in the past . The charts are used for a reason , and I have found its better to error on the stiff side , you are way on the week side .

Run your settup thru the program on bowjacksons website , he has alot of other great info there allso.

www.bowjackson.com