High at 50 yards?

[ELLIS]

I am shooting 3D targets at tournaments only, I am not a hunter.

I am shooting Excalibur's carbon Firebolts with 100 grain bullet field points and Blazer X2 vanes helical offset.  They weigh in at exactly 350 grains.  My bow is a 2011 Eqiunox with a Boo 40 strand string and a DLX Twilight scope.

This weekend I was sighting in the scope shooting from a bench.  There was no wind at all during the day. Everything was fine at ten, twenty, thirty and forty yards. The cross hairs and chevrons matched up to the distances. At fifty yards the arrows went consistently high (four to five inches). The target I am shooting at is a Bulldog Doghouse XP whose target faces are covered with one inch black dots.

Does anyone have any idea what is going on at fifty yards with the scope? Prior to this I was shooting factory carbon Firebolts (with 100 grain bullet field points and four inch vanes) weighting 370 grains and the scope was dead on.

[wabi]

Did you re-check accuracy at the shorter ranges?

[ELLIS]

I did and they are dead on.......

[wabi]

Only guess I have is that the reticle in the scope is off.
I'd call Excalibur and tell them what is happening.

[Bones]

Yep!! what Wabi said, A friend of mine his Twilight did the same thing. Our camp in 6 years have gone through 3 Vari zones, 3 lumizones, 1 shadow and 1 twilight? 6 out of 8 shoot excal's. My vari zone died this year.
Bones

[shafferm]

You decreased your weight from 370 to 350, depending on your change in FOC the arrows may not be nose diving hard enough at the 50 yard mark.

I would try 125 and 150 grain field tips and see if you are able to get either of those combinations to get all of the scope chevrons to match. If changing field tip weights does not show much of an improvement then I would give Excalibur a call.

[sumner4991]

Aim one inch low at 50 yards . . .as long as it's consistant, no problem, right?

[Ibex]

I am using a Vortex 3x crossbow scope on my Ibex shooting at 290 fps. 20, 30 and 40 yards are dead on but 50 yards is 5" to 6" high. My foc is 23%.

Fran

[ELLIS]

Before altering my set up I was using factory Excalibur carbon Firebolts with 100 grain bullet field points (weighed 370 grains). The crosshairs and all of chevrons of the Twilight scope were dead on from 10 to 50 yards.

I then shaved the factory vanes off and put on Blazer X2 vanes helical offset. This removed ~20 grains from the arrow’s backend because of the much lighter vanes. This made the front end heavier than that of the factory arrow dynamics but also made them fly faster. I assume that the FOCs of the altered arrows would be better that that of the factory ones. Am I right or wrong about this? I did notice that these vanes did give me much tighter groups.

This weekend I am thinking about re-sighting in the scope but this time experiment by increasing the scope’s speed ring a little more. Maybe this will tighten up all distances. If it doesn’t, I will set things up as well as I can get and will have to aim lower at 50 yards to compensate for this abnormality.

Thanks for the replies!

[Boo]

Bill, did you set up your scope with a plumb bob and level? It won't take much to raise your point of impact at 50.

[ELLIS]

That was the first thing I did when the scope was installed. I then added a anti-cant level to the scope housing. This level is checked before taking every a shot.

Thanks for the thought Don.

[DuckHunt]

Ellis,
I've has a somewhat similar issue. When my Exomax was dead on at 20, it would be a bit high at longer ranges. I had my speed ring set at max (350). I think mine must have been clocking a little over 350. I checked everything and noticed my brace height was on or in front of the front notch. I added a few twists to the string to bring it closer to the back notch. That took 1/2" or so off the stroke so it slows it down a few FPS. It was enough to cure my problem.

Of course it was only a problem in target practice cause that is the only place I ever toss an arrow more than 40 yards.

DuckHunt