On the topic of finding BC's. My take is that for average LRH ranges say 0-700 yards, the 2 chrony method works rather well most of the time. When you exceed that, it can still work decently but you cannot get a drag model from the typical 2 chrony method. The drop test (IMHO) is better for determining a drag model versus a BC.
Twice last year I ran different bullets over 2 seperate chronies. After gathering the data and examining the numbers I was able to set up at 700 yards and both times make first round hits in the center of the X ring. When I say the center of the X ring I meen the center of the X ring. 2 different bullets, two different months at 2 different locations. One bullet was off by .015 from published and the other was .009 from published. It was simple, easy and obviously VERY effective. Sight in, double chrony, verify zero, shoot 700 yards, life is good.
It should be noted that both chronies were fired over together at 100 yards lined up with eachother perfectly. One is 32 FPS faster than the other. Several bullets were fired over both several different times at 100 yards and close up. The verdict was always 32-33 FPS. I simply would fire over both (600 feet apart CL to CL) and would deduct 32 FPS from the faster chrony. At times when the lighting, wind and mirage cooperate, I will set them up 900' apart. Most of the time however, 600' (200 yards) has to do.
Is doppler rader the best way? I think so. Are double chronies effective? Absolutely. I have worked in the past with pressure transducers and a high speed clock for time of flight and it is a royal pain in the *** as well as expensive with all the hardware, software, cables etc..... I dont mess with it any more due to the simplicity of the double chrony method. It may not give you first round 1000 yard X's but sure will get you on paper.
Wow Paul, you really have gone off the deep end here. But I'll play along so that it may benefit others.
Can you not read? I'll speak slowly for you. Yes, the BC claims made by LV are total, complete and utter BS. Fantasy. Was that clear enough for you?
This does not mean the bullets have low BC's or are bad bullets. In fact, I'm sure they have very good BC's and enough people have had good luck with them accuracy and terminal performance wise to conclude they are good bullets. As mentioned I bought a bunch of them and if my barrel had liked them better I would have used them with whatever BC I measured--which I'm sure would have been quite good.
But that, or even if you assume for the sake of argument they're the best bullets in the world does not justify furthering the BC fantasy that has been presented. That benefits nobody. In fact, it harms readers by misinforming them.
An effort to help people. I come from a family of teachers, I guess it's in my nature. I want to help people understand. Long range enthusiasts reading this will buy a ton of bullets over the years. Helping them understand the hows and the whys of what bullets do what they do so they can understand the subject matter better and make good choices in the future is something you can try an demonize if you want, I guess, but I don't think it's very helpful to anybody here.
You can tell from the posts here there is still a great many people who think that longer bullet = higher BC! A large percentage of HAT bullet buyers likely use that as a reason to believe the BC's because that's what LV has told them. This bullet is X long compared with a 300 SMK therefore its BC must be Y! The sooner these people understand what gives a bullet BC, the better off they'll be.
The overwhelming majority of the drag on a bullet happens at its nose and its tail. When you have a nose and a tail shape that are not much different than many other bullets out there, you simply can't get a form factor radically different from those other bullets either.
So when you're stuck with a certain level of form factor, you can only realistically expect so much BC for a certain sectional density. There is no trick. There is no magic way around it. You can increase the aluminum percentage in the bullet and make it longer, and longer, and longer....but unless you change the shape of the nose or the tail or make the bullet HEAVIER, you will not increase the BC.
These are simple facts of exterior ballistics. Hunters and LR shooters are often very resistant to accepting them because getting something for nothing always sounds like more fun--a light bullet that still works through your magazine (same nose length) but has the BC of a much heavier bullet but you can launch it much faster! Doesn't that sound great?
The sooner people understand how things work and recognize what aspects of bullet design do and which ones don't increase BC the sooner they'll be able to make choices that suit them best and spend their money wisely and the more they'll demand from bullet makers bullets that work better for their application.
Now if that is a purpose you feel deserves continued attack; a purpose you feel is somehow for the sake of my own personal gain (what on earth would that be?), I feel sorry for you. The only thing you're shining a light on is yourself.
If I started sending you bills for my time in providing these consultations at my hourly rate, then you might have a case I was attempting to exact some sort of personal gain.
SNIP.
I've played with Patagonia Ballistics LoadBase ballistics software (a commercially sold ballistics program) and I was quite certain inputting a longer bullet increased BC. Is there no affect, or are you simply saying there is very real limit to the benefit of a longer bullet?
Jon,
Now this rings of teaching. Present the information for digestion, consideration, understanding, and the benefit of others. This fits right in line with the vast majority of the posts you've contributed on this Forum. Why did you save the teaching until now?
I don't have access to my LoadBase ballistics program, but I was under the impression that BC increased with bullet length - all other bullet parameters remaining constant. I'm a registered engineer with a decent understanding of mathematics. I have not specialized in the field of exterior ballistics, but when I read the theory I have some capability of understanding. I've played with Patagonia Ballistics LoadBase ballistics software (a commercially sold ballistics program) and I was quite certain inputting a longer bullet increased BC. Is there no affect, or are you simply saying there is very real limit to the benefit of a longer bullet?
Two things:Then I'd have asked you for the correct BC for this bullet. Logic here would dictate absolute knowledge of the "correct" BC with associated limits of precision. Haven't heard that yet unless you concluded that Bryan's BC is the correct BC with the same conviction you dismiss LVs - and failed to mention it.
You were under a false impression. The BC does not change significantly. It can even go down a tiny bit due to increased skin drag.I was under the impression that BC increased with bullet length - all other bullet parameters remaining constant.
Two things:
1) Yes, I have complete faith in Bryan's testing. Any bullet he tests is one I don't have to because I know he will do a better job than I can.
2) Your premise that one needs to know an exact value before he can know another specific value is incorrect is a false one. If I tell you I am 12 feet tall, you can feel pretty secure in saying I'm full of crap without knowing my exact height.
You were under a false impression. The BC does not change significantly. It can even go down a tiny bit due to increased skin drag.
This illustrates my point very well. The claims made only seemed credible enough to you that you'd attack anybody questioning them due to your lack of knowledge of the subject matter. Your time may be better spent doing less attacking and more learning.