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Post by steve46511 on Oct 18, 2014 7:30:31 GMT -5
While reading posts the past few years it became obvious to me that others did not share the same opinion on how useful, or not really useful, the ballistic coefficient value stated by companies is for a big game rifle projectile. I won't bother with my own opinion. Opinions vary in this as in all factors of our sport but I came across a pdf file of an article posted by John Barsness and it debunks a lot of "beliefs" about such and I thought I would share it. Regardless if you personally feel it's worth going to extremes to get the caliber and bullet with the highest BC listed or if you feel it's just another thing to half pay attention to, there is information here I'm willing to wager few knew. Hopefully some will find the article informative and useful to help them when considering a caliber or projectile alone for future hunts. Even if you think you have a good grasp on what BC is......take a few minutes and read this when you have time to spare. God Bless Steve www.bergerbullets.com/articles/john-barsness-ballistic-coefficient.pdf |
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Post by esshup on Oct 18, 2014 14:11:46 GMT -5
If attention is paid when reading the article, what you'll see is that for most big game hunting the bc doesn't mean a thing.
But, I agree 110% with the article on the whole BC thing. If you are anal about accuracy, and putting a bullet precisely where you want it to go, then BC means a LOT.
I've found that BC figures are inflated by the majority of bullet makers, and that like the article says, velocity also matters. Case in point. That 7mm 175g Sierra Matchking bullet that they talk about? I called sierra and talked to their techs about it. It was the second phone call that I made to the same tech when what I was saying finally sunk in. His comment was "Wait a minute. HOW FAST did you say you were pushing that bullet??? When I told him it had a MV of 3475 fps his comment was "You're in uncharted territory, we've never pushed it that fast. What the he.. are you shooting??" In my testing at this elevation, I found that a G1 BC of .776 worked out pretty durn close from 300 yds to 1,000 yds.
But like the article says, anything under 300 yds, bc really doesn't figure into the equasion for most big game hunting scenarios, and that yardage figure, depending on muzzle velocity, could be pushed out a couple hundred yards further.
BUT, nothing compares to having actually shot that bullet at that velocity, at the temp and elevation that you will be hunting at. Even if you have a good ballistic program, portable weather station and a good laser rangefinder, you HAVE TO shoot it at the distances you will be hunting with it at to verify your drop chart. If not, it's about the same as going out without having even sighted in the rifle.
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Post by RoadKill on Oct 19, 2014 10:23:30 GMT -5
Good article, thanks for sharing. For most applications, a BC to the third decimal means nothing. To make use of that precision, requires accuracy that most don't have. In other words, why worry about a bullet impacting 2-4 inches higher when the group size at that range in 8-10 inches?
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Post by steve46511 on Oct 19, 2014 11:02:50 GMT -5
Good article, thanks for sharing. For most applications, a BC to the third decimal means nothing. To make use of that precision, requires accuracy that most don't have. In other words, why worry about a bullet impacting 2-4 inches higher when the group size at that range in 8-10 inches? Agreed but such a distance with such would be WAY past what I look much at but it IS at the very long ranges that a BC (actual one, not advertised one) is beneficial, or should I say NOTICABLY beneficial. Some may feel 300 yards is "normal range" but, IMO, it's on the brink of "LONG" by my definition, especially if only considering ranges we would shoot most times here (but refer back to the article on the distances Mr. Barsness recorded for shots the past 40 years as well). With 300 yards as a chosen comparison point here are two examples to compare. Both are .277 bullets, both are 130 grain, both leaving the barrel at 3100 fps.
The zero on both is 175 yards and also for both the "point blank range" is +/- 3 inches in trajectory. The first is a "real" bullet with a BC of .460 and the second is an imaginary bullet with a BC of .600, again, all other factors are identical. The only .277 bullet I am aware of having .600 or more BC at this time is the 150 grain Nosler long range accubond. No such beast exists in a 130 grain, .277 bore bullet with a BC as high as .600. The difference in BC from .460 to .600 is HUGE and is purposely RADICALLY different and WAY beyond what the (advertised) BC is available on any 130 grain .277 bullet. EVEN IF I could find a 130 grain .277 bullet with an advertised BC of .600.....this is how much "difference" there would be ON PAPER, out to 300 yards. I repeat. A 130 grain .277 bullet with the .600 BC in the second chart is IMAGINARY and not even available in one rated that high. The .460 BC bullet  and The imaginary .600 BC bullet  Again, just info. God Bless |
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