Re: Ogive question.
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Among many other things BC is also a function of weight. I cant imagine a 42 gr .22 bullet approaching the BC of a normally shaped 168 grain .30 cal no matter how long the ogive is.
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BC is a number you can get from the formula sectional density times form factor.
Sectional density= bullet wt in pounds/diameter squared in inches.
if you used the .800 BC somebody was dreaming about, and used the same form factor as the 210bergervld(2.023765)...
it would be 2.023765X(139/7000/.224squared)=.800BC
Thats a 139gr bullet.
If you wanted the same BC as the 168SMK (.462) its possible, but you gotta drive up the weight a good bit to make it.
168SMK BC .462, Form factor1.82
80BergerVld BC .489, Form factor 2.147
75BergerVLD BC .448, Form factor 2.098
A 42gr, .462 BC .224caliber bullet is possible, the problem is that with a bullet that long, you need a super fast twist, and that super fast twist magnifies the inconsistancies in the bullet that make accuracy virtually impossible.
Now for a brief history lesson....
There were a few shooters that were experimenting with very high bc 30 caliber bullets back in the late 80s and early 90s. They only weighed 250gr, but had BCs of well.... really high.
Problem was, the only way to get workable bullets was to lathe turn them, then test them on a Juenke machine. With a high percentage of the bullets weeded out due to the fact that extreeeeemly low readings on the Juenke were nessicary to even hit paper due to the very high RPMs involved.It turned out to be cost prohibitive. From what i recall, rejection rates were about 80-85 per 100.
Thats right boys and girls, those expensive, custom, lathe turned bullets go into the trash at a rate of better than 80%
Like I said, its possible, just not really practical yet. Oh, then theres the custom barrel. No... really custom barrel, as in the tooling is custom. I think the barrel was a 30" 1:4.5..... something like that, memory kinda foggy.
One of these days we'll be able to buy bullets with those super high BCs, but they will have to be shipped in a shock absorbing container. Those pristine bullets that made it through the Junike with high scores(um.. technically low scores)... drop it on a hard surface from as little as 12" and its toast. What does the average package look like when the big brown truck drops it off?