Dynamic spine question

[PriceTA13]

Hello, I have a general understanding about dynamic spine, but was just wanting to clarify this one part. As the dynamic spine gets too weak, my understanding is your groups will start to expand. My question is if this will be exaggerated once broadheads are put in, or if it's all about the weight, and the blades won't affect that aspect of it. Thanks,

 

[MattB]

The affect of the condition tends to be exaggerated with BH's as compared to field points.

 

[PriceTA13]

Mattb that's kind of what I was figuring. So even if my arrows seem to group acceptably well with field points, they might expand with broadheads. That means I should really almost start with broadheads until I know they're spined right, and then go back to field points.

 

[Jimbob]

Mattb that's kind of what I was figuring. So even if my arrows seem to group acceptably well with field points, they might expand with broadheads. That means I should really almost start with broadheads until I know they're spined right, and then go back to field points.

Not really.

Use a software program to set up an arrow that matches the exact specs of your bow. Then build your arrows and start tuning. If the bow won't tune with that arrow set-up then it might be a bow issue or a spine issue. If you use a software program it should pretty much guarantee an acceptable spine though.

MANY different ways to tune a bow, paper tune, bare shaft tune, broadhead tune, walk balk tune. Most people use a combination of all of those. You will certainly shoot field points when tuning though.

 

[Billy Goat]

It's a little complicated in my experience. A "weaker" spine will shoot slightly better from what I have seen with field points. I suspect it's a bit more forgiving. Throw a broadhead on those same arrows and you're in trouble. I think the programs take this into account, they have a target and a hunting setting from what I have read, I don't use them.


Broadheads also amplify any problems.

 

[RosinBag]

Billy Goat is spot on, weaker spine is equal to better groups especially at long range.

The worlds best shoots a 520 spine arrow with 60 pounds and 120 grains up front. On paper this is super weak, but in reality, they are more forgiving and group the best.

This is purely field points though. I wouldn’t go weaker either a fixed blade BH.