Free Ballistic Software

[PegLeg45]

For the record, this is not in any way bashing ballistic software.


I guess I'm like Clint Smith....old fashioned.......

I just shoot the rifle and see where the bullet hits and then correct for that.   

I understand the tables and such are a good indicator and starting point (and will get you in the ball park), but they don't always add up. I've seen too many people swear on them as gospel for shooting and IMHO, that is a slippery slope.


**As a side note, and funny story (shades of FQ here  ).....
I had a similar incident happen at our range that Clint wrote about in a past article. A guy had sighted in his rifle at 100yds and then when he went out to 300, after setting the scope to the pre-determined BS dope, the bullet was still hitting about an inch and a half low. And this guy just kept bangin' away at the target and wondering why it was hitting low....and it wasn't his shooting, because he was clustering a nice grouping...just consistently low. So I asked him why he just didn't adjust his come-up number and bring it up about a half-minute.......you would have thought I had just slapped his wife on the rump...... I just left him scratching his head. 


As I said, this is not a snark at the software....just an observation. 

[Solus]

For the record, this is not in any way bashing ballistic software.


I guess I'm like Clint Smith....old fashioned.......

I just shoot the rifle and see where the bullet hits and then correct for that.   

I understand the tables and such are a good indicator and starting point (and will get you in the ball park), but they don't always add up. I've seen too many people swear on them as gospel for shooting and IMHO, that is a slippery slope.


**As a side note, and funny story (shades of FQ here  ).....
I had a similar incident happen at our range that Clint wrote about in a past article. A guy had sighted in his rifle at 100yds and then when he went out to 300, after setting the scope to the pre-determined BS dope, the bullet was still hitting about an inch and a half low. And this guy just kept bangin' away at the target and wondering why it was hitting low....and it wasn't his shooting, because he was clustering a nice grouping...just consistently low. So I asked him why he just didn't adjust his come-up number and bring it up about a half-minute.......you would have thought I had just slapped his wife on the rump...... I just left him scratching his head. 


As I said, this is not a snark at the software....just an observation. 

Anyone who uses the calculators without checking their rounds with a chronograph can expect big discrepancies.

Using the manufacturers published velocity isn't reliable because they usually use a 10" test barrel for handgun cartridges and that is not going to be close to what is on  your hip unless your last name is Earp and you are toting a gift from your friend Ned. (which is likely a 'myth')

Rifle barrels will vary from what was used to product the published velocities also.

Next you need to know the ballistic coefficient of the bullet used in the round.  This won't make a lot of difference at short ranges for the cartridge under consideration, but it will make big differences at the longer ranges.  All that drag adds up.

All those other parameters won't make much difference at SD handgun ranges.  Shooting into a 40mph head wind is going to affect your 300yd shot particularly if you are shooting a bullet with a poor ballistic coefficient, like a round nose.

But you aren't going to know the wind velocity and direction unless  you are target shooting and doing your calculations at the bench....or are using the scope described in Stephen Hunter's novel, I, Sniper.

Again, the speed and ballistic coefficient are the most important parameters.  You will notice that this software asks the distance from the muzzle to the chrono.  This is because it expects the velocity entered to be at the chrono and it need to calculate the the muzzle velocity using the ballistic coefficient.  That they do this shows how critical a correct velocity is to the calculations.

[Solus]

Sorry, you're talking 50 yards.  I see that now...

Ahhh...

When I first played with this, it was to see what to expect from a .45 ACP round used for SD.  I figured if the range was greater than 50 yds you should have better options than shooting available for awhile.

What I was going for was a zero that would give +/- 2" from point blank to 50 yds.   I believe I found a 33ft zero did that.  I did not, however, verify that with actually fire.  Without a machine rest, holding 2" at 50 yds was beyond my capability.

I was surprised that the big and slow .45 ACP required no aim point considerations at these SD ranges, even if zeroed at a more 'usual' range.

[Timothy]

Nothing too scientific for me...

We put an IDPA target out at 25 and 50.  Center mass hits at 25 and aim at or about the collar bone to get similar results at 50 yards.  Obviously the spread was wider but it provided the information we were looking for!  It very well could have been +/- 2 or 3" but I can't shoot a 2" group at 25 yards offhand because I don't shoot enough.