I'm having the same debate ccamp200. going this weekend, I've had mine on my S&W M&P 15 sport2. works great! upgraded the IR light working on the scope height in profile settings once I get a caliper tomorrow. I like it on the low light white NV setting, I'm clear out to around 300yrds on high. Then new profile for Barnett Ghost 380. I think with a little practice out to 60yrds should be VERY comfortable with a 2" Schwacker as I'm hitting consistent bulls @ 80yrds now. I just cant find anything for "crossbow" but I'm gonna try 100gr with 380fps and ?? BC? @ 50yrds I'd like an update if ya figure it out.
Good hunting, Yancy
Should probably weigh the bolt. My guess is that the target tip alone weighs 100 grains. Total bolt weight is probably closer to 330~350 grains. Mine weigh in at 400 grains with target tip. I also use 100 gr. broadheads, so no gross changes from target to hunting.
Suggest using a G1 profile with a BC somewhere between .25 and .08. BC doesn't seem to affect bolt (or arrow) drop at these short ranges as much as it does a bullet at a couple hundred yards.
More important is adjusting for correct arrow speed.
Go to current profile and make some BC adjustments without changing muzzle velocity. Exit the profile and look at the ballistic calculations on the screen. BC will not make as much changes as you might assume at these relatively short distances.
We're talking the difference in arrow drop with a BC between 0.08 and 1.1 from 30 to 50 yards at a given muzzle velocity of 430fps is only a about 0.30~ 0.450". Think about that. The arrow is 5/16" dia. If you breath funny your arrow is off by 2" or more.
By the time you have worked out some B.C. close to your arrow drop, your string has relaxed, fps has slowed down, and the calculations are no longer relevant.
In archery, you're trying to hit a paper plate-sized sweet spot at 50 yards. If you set it up right, 3/4" groups at 50 yards are easily doable. Blood on the ground and meat in the freezer.
Crossbows show signs of string wear much faster than rifling does in a rifle barrel. Things can change in a hurry. You can wear a string out trying to zero it in. My Ravin string is only good for about 200 shots before things start to go south.
When you replace the strings, speed goes back up. Back to zeroing it in again.
If you don't have access to a chronograph, use the mfg specified arrow speed, a G1 profile, a BC of 0.25. Set your zero range to 30 yards and Dead nuts Zero your crossbow at 30 yards. Move the target out to exactly 50 or 60 yards. Reset your target input yardage to 50 yards (or 60 yards, whichever you chose) and take a shot. Do not re-zero the scope at this yardage. Only messes up the ballistics math. Windage adjustments are ok, just don't re-zero elevation. Only adjust your muzzle/arrow speed from this point.
If you POI is high in the target, go back into the current profile and increase the muzzle velocity by 10 fps or so. Limit the fps changes as the arrow approaches your POA. As arrow speed increases in the Ballistic calculator, this raises the POA/reticle. Realignment to target then lowers the crossbow, lowering your POI until the arrow drops into the bulls eye. Conversely, if the arrow falls short, decrease the muzzle/arrow velocity until your POI rises up to your POA.
This will adjust the ATN ballistics calculator to work at most of your crossbow ranges at the correct arrow speed out to about maybe 100 yards or so.
Or you can Zero it in at 50 yards and adjust your speed to hit bulls at 30. Either way works. Zero at 50 is probably easier to obtain more accurate windage adjustments.
Sight it in at 50 or 60 yards, and it will be a Tack driver for a crossbow.
My Ravin R-20 shoots .001 run-out match grade bolts at 430 fps and is sub-minute accurate from 30~135 yards with the ATN X-Sight II HD 5~20x on benchrest bags or with a bipod.
Do the same thing with any weapon. Make it as accurate as you can possibly make it. The rest is on you.
And it has NV. Yeah Buddy! Yotes gotta watch their 6 now.
Ravin R-20 crossbow with an ATN X-Sight II HD 5~20 and an 850 PRO IR is one Lethal Beast! Day or Nite.
Shoot Straight
