# Ballistic Question



## elkaddict11 (Jun 16, 2014)

I have a .50 T/C Encore. I'm shooting 130 grains of Pyrodex Powder Pellets and Hornady 300 grain SST. I am currently sighted in at 3" at 100yds getting 1 1/2" groups. I have been searching the internet for some kind of ballistic chart and have come up empty handed. I did find some ballistic calculators but without have a chroni to figure out my muzzle velocity, they didn't do me much good. 
I was wondering if anyone knew of a web site you could send me too or any information. It would be greatly appreciated!


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## DallanC (Jan 13, 2009)

You would need the height at two different distances to compute all the rest of the variables.

I kinda know a whole lot about ballistics 


-DallanC


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## elkaddict11 (Jun 16, 2014)

At 25yds I am right on. Or do you need a longer distance?


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## massmanute (Apr 23, 2012)

elkaddict11 said:


> At 25yds I am right on. Or do you need a longer distance?


If you knew the perfect, error-free result at 25 yd it would be useful information, but as a practical matter, due to the amplification of small errors in a calculation, the 25yd result would not be very useful.


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## DallanC (Jan 13, 2009)

That 25 yard zero seems bogus, like massmanute said shorter distances have greater errors.

That said, the 300grn SST has a BC of .250, not knowing your barrel length and muzzle velocity, I guesstimated it at 1850fps. Assuming those variables, I came up with this, zero'd at 156 yards:










-DallanC


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## elkaddict11 (Jun 16, 2014)

What would be an ideal second distance? I have a 26" barrel on it if that helps at all. I'm very naive when it comes to ballistics, please excuse my stupidity.


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## DallanC (Jan 13, 2009)

elkaddict11 said:


> What would be an ideal second distance? I have a 26" barrel on it if that helps at all. I'm very naive when it comes to ballistics, please excuse my stupidity.


Not at all "stupid", in fact your questions are some of the better ones on this site lately :mrgreen:

Don't adjust the scope, shoot a target at 75 and maybe 125. Just as a FYI, I'm the author of a very popular PC ballistics program called PointBlank, its completely free and available at HuntingNut.com. I also wrote an "online" version for fast computations, that is what the above picture is from.

"BC" stands for ballistic coefficent and is a measurement of how well the bullet moves through the air. 1 is perfect, your SST is around .250 according to Hornady (all mfg values are suspect however). Some uber long range rifle bullets are getting near to having a BC of .6 which is remarkable. Anything over .4 is a pretty streamline bullet. Pistol bullets are just to wide and short to ever have much of a SD.

-DallanC


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## elkaddict11 (Jun 16, 2014)

I will have to look into that! Thank you for all the information!


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