What Effects Arrow POI? - FPs vs BHs

[nchunterkw]

Been seeing a lot of posts about changing POI etc and thought it would be a good idea to start a thread to gather a lot of info into one area.
Please post your thoughts /ideas on how to get your hunting arrows ready.

I'll start with BH Planing
When you put a fixed blade BH on the front of an arrow you essentially put wings on the front. Those wings have some ability to steer the arrow. Their ability to steer needs to be overcome by the ability of the fletching to steer the arrow from the rear - as they do when you have a FP on the front. Ways to do this are to use longer fletching, or fletchings put on with lots of helical.

This is also why mechanical heads have achieved good popularity. They fly "like FPs" because they do not have large flat surfaces lie a fixed head.

My experience with Planing is that instead of flying in a very tight spiral to the target, the BH causes the spiral flight to "open up", and you see completely different POIs at different distances. (at 20 yds maybe high and right, but at 30 yds low left). Is this your experience, or do you just see the POI shift, and remain consistent at different distances?

[bob1961]

insert weight also has a lot to do with how good a arrow will fly....I used a straight fletch using blazers and had my slick tricks flying to the same spot my target tips were going out to 50 yards with 550gr 2117 alum arrows with 160gr brass inserts....I now have my arrows down to 500gr with 110gr brass inserts and use a 2 degree right offset EZ fletch jig with the same POI out to 50 yards still....IMO bout expendable's are they help to eliminate bad shots due to not having a good arrow set up to fly where one aims them to hit with fixed heads....I have never had any troubles using fixed broad heads ever from the start of using my 210fps compound back in 1980 with 2117 alum arrows with bear razor heads ....

[fuzzy]

...

[galamb]

I have horsed around with numerous different arrows and broadheads.

I have a 25 yard range in my back yard and lot's of time.

The basic conclusion I have drawn is as follows:

If you keep your shots under 35 yards you can select any combination on the market today - whatever bolts, with whatever vanes, with any nock or insert and any broadhead and with very very very few exceptions you can regularly hit the target within a 3" group.

I have even shot bare shafts from 25 yards with broadheads and got sub 4" groups - no problem at all.

Where I see issues arising are - shooting minimal weight bolts/arrows, with tiny little vanes and a fixed head.

And from all my "non-scientific" testing I have CONSISTENTLY found that the best/tightest groupings have been with extreme weight forward arrows (90-110 grain inserts giving you an FOC of 18% or more - personally shoot 22%) on heavy shafts with minimally 4" vanes, with 5" vanes being better, coupled with an expandable broadhead.

No, this will not get you anywhere near the "advertised speed" capability of the bow.

However, most guys/gals don't want to shoot a 450 grain set-up with a 5" vane - they feel the need to shoot 351 grains with 2" blazers and then go with a fixed head because "they don't trust the mechanicals".

The only time that speed truly kills a deer is when it get's hit by your vehicle going to/from your stand.

If you want truly "tack driving" accuracy in "all" wind/weather conditions you need to go with heavier bolts, extreme FOC, "massive" vanes and a mechanical head - and I have a garage full of bolts/broadheads from all the major mfg's, plus an assortment of custom bolts to back up my conclusions - after shooting them all, those are the facts I have personally found.

You are always trading off when you choose anything. The most accurate is "slower", the "fastest" has the most propensity to fly wild (and probably when the Buck of a lifetime is in front of you). Somewhere in the middle is what most of us can live with....

If you want to shoot fixed broadheads you should probably be shooting above 400 grains with longer/higher vanes.

[Boo]

My experience with Planing is that instead of flying in a very tight spiral to the target, the BH causes the spiral flight to "open up", and you see completely different POIs at different distances. (at 20 yds maybe high and right, but at 30 yds low left). Is this your experience, or do you just see the POI shift, and remain consistent at different distances?

A broadhead out of alignment or a shaft that is not very straight or one that is dramatically underspined can cause a lot of yaw. Basically anything that makes the arrow assembly uneven or not uniform.
Basically the point travels in a circle and some part of the shaft will remain in the middle. It is, as you indicated, allowed to happen with broadheads because the blades provide a "bite" in the air and but to a very small degree target points because they are round and do not allow any "bite".
I believe that is the phenomena you are seeing.

[paulaboutform]

I agree with just about everything galamb stated with one exception. I believe you don't need a longer vein if you have a higher profile shorter vein such as the much loved blazer.I think the first order of business is to start with a straight shaft. Second is to square both ends of the shaft. Third is to square your flat nocks and inserts when they're in the shaft. Third is to have a heavy insert. Depending on your setup i like 92gr or 110gr worth of inserts for me. 92gr brass inserts and 100gr broadheads fly great with 8 gr plastic nocks on my 18" Zombies but when I use 28gr Luminoks they change my foc enough to not group as tightly. I'm talking about 3 1/2" groups at 65yards which is good but I'd like to see sub 2" groups at 65yards with broadheads. For this reason I'm going to 110 grain brass inserts and 100gr broadheads for my hunting setup. And last but certainly not least, i like the 2"blazers set with an extreme offset using the bolt ez fletcher or something equivalent. The shorter veins seem to be less affected by wind and the heavy front end combined with the extreme offset veins seems to give the most stability and forgiveness. That's just my setup and my opinion. I'm sure there are many setups that work great, this is just what I've found works for me.

[Masboy]

Th easy way that works for me is I shoot bare shafts an sort out arrows that shoot great groups with fieldpoints an same poi at 30 yds. then fletch them an put on a good spinning broadhead an shoot them an in my quiver they go. for my best arrows I shoot bare shafts at 50yds. an get 2 inch groups from them an then fletch an shoot broadheads an works for me saving lots of time.

[nchunterkw]

Th easy way that works for me is I shoot bare shafts an sort out arrows that shoot great groups with fieldpoints an same poi at 30 yds. then fletch them an put on a good spinning broadhead an shoot them an in my quiver they go. for my best arrows I shoot bare shafts at 50yds. an get 2 inch groups from them an then fletch an shoot broadheads an works for me saving lots of time.

I think I'll give the bare shaft thing a try. Although I'm not having any troubles at the moment.

[nchunterkw]

I agree with just about everything galamb stated with one exception. I believe you don't need a longer vein if you have a higher profile shorter vein such as the much loved blazer.I think the first order of business is to start with a straight shaft. Second is to square both ends of the shaft. Third is to square your flat nocks and inserts when they're in the shaft. Third is to have a heavy insert. Depending on your setup i like 92gr or 110gr worth of inserts for me. 92gr brass inserts and 100gr broadheads fly great with 8 gr plastic nocks on my 18" Zombies but when I use 28gr Luminoks they change my foc enough to not group as tightly. I'm talking about 3 1/2" groups at 65yards which is good but I'd like to see sub 2" groups at 65yards with broadheads. For this reason I'm going to 110 grain brass inserts and 100gr broadheads for my hunting setup. And last but certainly not least, i like the 2"blazers set with an extreme offset using the bolt ez fletcher or something equivalent. The shorter veins seem to be less affected by wind and the heavy front end combined with the extreme offset veins seems to give the most stability and forgiveness. That's just my setup and my opinion. I'm sure there are many setups that work great, this is just what I've found works for me.

I agree with this 100%, and I am using about the same exact setup. 110gr brass inserts, 20" Zombies, 2" Rayzrs (feather), 8gr flat nocks.

I can only shoot 40yds comfortably in my backyard, so my yardstick is sub 2" groups at that yardage with fixed blade heads.

[nchunterkw]

Thanks for the posts....I hope this helps some of the "new to crossbows" guys trying to achieve good BH flight.

As you can see, really good accuracy is achievable using fixed blade heads at long distances (compared to hunting distances) by paying attention to all the small details and understanding some basic flight characteristics.