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Is there a ballistic calculator that can................
- Thread starter justinp61
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PddPdd
Well-Known Member
I think most calculators would allow you to tweak muzzle velocity until you are seeing the drop that matches your drop data for a given range.
FrogFire7
Well-Known Member
Right... Should be able to input your zero distance, then adjust velocity until your drop data is accurate. I would strongly advise more than one drop data point but you will likely be close.
If you have the "actual" velocity of your load combination out of your rifle, most ballistic calculator will calculate the bullet drop at range Xs. As others noted, you can tweak them accordingly.
MallardAddict
Well-Known Member
I'm guessing the OP doesn't have access to a chronograph and is curious if they can extrapolate their velocity simply by inputting projectile weight and known drops.
The OP can of course come close by guessing at velocity and then tweaking it until the drops on the chart line up to actual drops in the field. That said it will only get you close as the app can't account for SD and ES variations.
Agreed! That's why I noted "actual" velocity because I did not want to assume anything.
Sniper hide has a bunch of good videos that explain how to use the math and apps. I think they call it weaponized math. Check it out.
I'm gonna presume you don't have access to a chronograph or a LabRadar. Since those are the best means of determining bullet velocity.
The answer is no. Not based solely on bullet drop and bullet weight. You at least need to know the bullet BC value on order to back calculate a bullet velocity with a ballistics program. And you'll need to know the air density at the time and location where you measured your bullet drops.
Even using a bullet's advertised BC value, understand that some bullets today are still marketed with incorrect bullet BC values. Some BC values error by more than 35% from their true value.
Also, determining MV by measured bullet drops using a ballistics program, even if you did have an accurate BC value for the bullet, is still fraught with potential for significant error. This has been documented. Because some of the bullets with the largest error in manufacturer BC value have based their BC values on measured bullet drops.
My suggestion. Find someone with a chronograpgh or LabRadar. See if they'll record a couple of bullet velocities for you.
Thanks guys. I have a chronograph that I use for my air guns but have never really put any emphasis on my centerfire velocity. My goal has always been accuracy within the load range for a particular powder and bullet.
Last year I screwed together a couple LH Savages, a 260 and a 22-250, both with Shilen barrels. The load development was done, and the rifles zeroed, the 22-250 was zeroed at 200 yards and the 260 at 100. Neither rifle had been shot past 200, so yesterday I shot the 260 at 100, 200 and 300, the 22-250 was shot at 200, 300 and 400 yards. I wanted to get the actual drops.
After shooting them is when the idea came that there may be a calculator that would backwards engineer the velocity. I honestly didn't think about adjusting the velocity in a ballistic calculator to make the drops match the actual drop. Sometimes I can't see the forest for the trees, LOL. I now have a number using the advertised BC's, bullet weights and my drops. After I load some more rounds for each, I'll set up the chronograph and see how close the numbers are.
Justin
Last year I screwed together a couple LH Savages, a 260 and a 22-250, both with Shilen barrels. The load development was done, and the rifles zeroed, the 22-250 was zeroed at 200 yards and the 260 at 100. Neither rifle had been shot past 200, so yesterday I shot the 260 at 100, 200 and 300, the 22-250 was shot at 200, 300 and 400 yards. I wanted to get the actual drops.
After shooting them is when the idea came that there may be a calculator that would backwards engineer the velocity. I honestly didn't think about adjusting the velocity in a ballistic calculator to make the drops match the actual drop. Sometimes I can't see the forest for the trees, LOL. I now have a number using the advertised BC's, bullet weights and my drops. After I load some more rounds for each, I'll set up the chronograph and see how close the numbers are.
Justin
