Truing your Muzzle Velocity (MV) and Ballistic Coefficient (BC) - What is it and why do we do it?

Horus is here to answer all your long range shooting questions. Why do we need to True? You have a good chronograph know your BC and have a good muzzle velocity, do you still need to true?
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[@7thRecce]

Ahhh Sniper Jesus....keep the content coming!

[@CallumHepworth-Smith]

Well that was clear as mud!! LOL. Can you explain how to adjust the BC if the speed data we get from the chrono is correct.... - increase the BC will make the bullet impact do what? (drop or raise?) - decreasing the BC will make the impact do what? (drop or raise)

[@sfoxakafoxy]

Learned so much from watching content made by Todd at Accuracy 1st. I’d love to meet the guy one day to thank him personally.

[@schoocg]

Love your stuff, more more more please!

[@HorusVision]

We'll be releasing a new video weekly! Let us know if you have a topic you'd like covered.

[@discogodfather22]

I find myself being driven crazy by my past efforts with Truing. I use the AB software, and I have gotten lost a bit. I first compared results based on hits at 250 yard increments, trying to see where my data lined up. If I was short at 450 and on at 700, I would adjust the value, etc. The AB software only allows for 3 different ranges and drops for the compensation algorithm to run, right? My problem with that is that it is dependent on the longest distance, so if you want to shoot at 3500 yards it requires the first range to be at 1500, 3000, and 3500 respectively. Pretty difficult to pull off! Is there a way to do a video where it goes into the actual process? I find myself blindly fiddling with BC.........

[@HorusVision]

Absolutely. That's a great suggestion. We'll be filming a second set of videos this winter and I've added your topic to the list. Thanks!

[@Remsy-wo7th]

You must also true your rifle’s scope! Verify any scope by doing a tall target scope target!

[@HorusVision]

Absolutely, that's why we offer our CATS Targest www.horusvision.com/cats

[@rodneydockter7380]

Ok, so if i am 7 inches low at 850 yards do i add or subtract 7 inches to the trajectory validation in the inches setting on the ballistic calculator??

[@HorusVision]

I'm not sure what program your using where you can input inches but you'll need to do whichever lowers your Muzzle Velocity until it gives you an elevation solution that gives you the correct elevation hold at 850 yards. If you need more clarification feel free to call us at [phone] and we can walk you through it!

[@RangerCaptain11A]

you always move the point of impact to the point of aim. so you have to come up 7". just fake example numbers here but let's say you dialed 21 MOA and your impact is 7" low. that is 3/4 MOA low (7/8.5 = 0.82 round to 3/4. the 8.5 is 1 MOA at 850 yds ) if you dial 21.75 your impact should be good.

[@RangerCaptain11A]

thank you for trying to explain this. the MV is a fixed number, the BC is a best guess, and the track of the bullet is a fact (that can vary due to weather and altitude), so to get the model (whatever ballistic solver you use) to fit the bullet track, we tweak the inputs MV and BC. I understand the velocity changes/decreases, but why are we acting like the BC changes?

[@HorusVision]

It's not that the BC changes, but that the BC is not neccsarily the same as the box says due to lot deviation, possible barrel distortions, etc. and this shows up more as the bullet slows down as the BC has a higher influence on the trajectory at lower velocities. Where at closer distance the MV has larger influence on the trajectory, sort of overcoming the BC to some extent.

[@RangerCaptain11A]

@@HorusVision thank you, i just finished a class about this. the app and the kestrel were off from my groups at 800 yds and i wanted to true the curve with my actual drop, but my instructor said not to unless you're within 10% of transonic (@ 1000 yds). so now i will fiddle with the BC. hornady gave the BC as .580 G-1 so my G-7 number is probably a best guess.

[@2bfrank657]

If your BC is off, why would you adjust muzzle velocity in your calculations? Surely you'd want to use your actual muzzle velocity and actual drops to work out your actual BC, then use that from thereon.

[@HorusVision]

Truing is used when you don't have any way to precisely measure your BC/MV. If you know your exact BC/MV it's easy, use them and it will give you a good output. If you don't for sure truing is a way to account for the error you're seeing. You true MV or BC based on being in super or subsonic as in super MV is a more dominant variable in the calculations and in sub BC is so it's more accurate. Not as good as having the instruments to accurately measure MV/BC but most folks don't have those so this is an alternatives that works well.