Interesting BC testing

[libidilatimmy]

http://dtic.mil/dtic/tr/fulltext/u2/a554683.pdf

Here's a report that I found pretty interesting that covers advertised ballistic coefficients versus measured ones. Figured some folks on here would be interested in the info as well.

 

[Gr8bawana]

That is very interesting, but so many numbers make my head hurt.

 

[jf239]

I have read a few of litz's books and many of his posts, i have used his bc's for many bullets out to 1500yards and his measurement are very very accurate with the g7 standard. I would suggest no one assume bullet company advertised bc to be accurate. Get litz's bc (g1 or g7) and you will put bullets on target

 

[Retterath]

interesting, good read

 

[micropterus79]

Interesting but a key piece of information missing here, I think, is how much variability is expected coming off the factory line in the first place? In other words, just like in all other manufacturing processes, bullets have to made within a certain tolerance or range of dimensions, weights, etc...What if these companies are just merely reporting the upper end of that dispersion. Their numbers have to come from SOMEWHERE.

What if you randomly selected various calibers from these manufacturers off the shelf and were able to accurately and repeatably measure your own ballistic coefficient? Would the variation you observe really (meaning statistically significant) exceed whatever industry standard there is?

 

[libidilatimmy]

And not to mention the methods of testing used to determine BC differ for each manufacturer as well. I've always noticed that the advertised BC from Nosler has always been overstated in the testing I've done through trial and error to obtain accurate solutions. I am about to start playing around with the 150 gr 7mm Accubond LR and was searching the world wide web for some verification on their BC, which I've heard from reliable sources that this line of bullets advertised BC is inflated by a good margin.

 

[WapitiBob]

Litz tested the LRAB's and published his findings on longrangehunting. They were close to advertised.

 

[micropterus79]

And not to mention the methods of testing used to determine BC differ for each manufacturer as well. I've always noticed that the advertised BC from Nosler has always been overstated in the testing I've done through trial and error to obtain accurate solutions. I am about to start playing around with the 150 gr 7mm Accubond LR and was searching the world wide web for some verification on their BC, which I've heard from reliable sources that this line of bullets advertised BC is inflated by a good margin.

Yes! Methodology is always important when considering these types of things. Are these companies just using the method that will produce more favorable results? Not technically lying but fudging. This is why people tend to get a bad impression of statistics and science.

 

[libidilatimmy]

Litz tested the LRAB's and published his findings on longrangehunting. They were close to advertised.

I have read that on his testing, and the two guy's I've spoke with that reported having to decrease BC by 6-8% for solutions in the heavy 7mm offerings pretty much fell in line with some of his results based on the conventional twist's they were shooting.