Actually, the use of the G1 drag model IS an attempt to standardize BCs within the industry. As Bryan has so aptly described, it's far from the ideal for most of the bullets we use. It is, however, something that everyone can relate to; you can check a Hornady against a Speer against a Sierra against a Berger, and they're all speaking the same language. This became normal practice way back in the late 40s early 50s when ED Lowery developed the G series of drag models. At that time, about the only folks discussing BCs were ballisticians. Stop and think back about the blank stare you'd have gotten even 10-15 years ago trying to discuss it with fellow shooters. Since they went "mainstream" the adherence to the G1 is merely an attempt to keep it simple, if you will.
As far as determining BCs, there's another kettle of fish. Problem is, many manufacturers don't have the facilities for determining an accurate BC. Over the years, you'd be flabbergasted to learn how someof those BCs were derived. Ever heard of the Coxe/Beuglass tables? They're listed in Hatcher's Notebook, if you want to see them and read about how they're used. Essentially, it involves visually holding a bullet up against an increasing series of ogival outlines and figuring out which "matched." From there, you had the values for a series of equations for the ogive, the meplat diameter, the boat tail, etc., that would give you a "BC" as gthe end result. Needless to say, the results could be off substantially. Hate to tell you how recently that method wasused by even some big industry names. Doing actual Time of Flight firing, or Doppler Radar testing are the only real way to determine the values, and that takes time, effort and money. The industry is getting there, more by the increasing sophistication of today's shooters than anything else. It's still a long road, but we've come a long way.
i dont agree with your blank stare comment regarding bullet bc 10 or 15 years ago. many of us understood the significence of bc long before that.
at least in pa. where im from, that was certainly the case among the long range shooting/hunting community.
i think it would be more accurate to say that due to the rather recent snowballing of those activities, more people are becoming aware of those terms.
certainly more interest is being shown due to increased numbers of participents.
frankly most hunters i know never hung their hat on any advertised statistics. those might cause the sale of a box for testing on the range and mountainside. finally on actual performance on game.
i could be wrong, but it appears to me the newer generation is more statisticly oriented. decisions seem to be made, based on computer generated facts.
now were finding not all those facts were facts at all?
weve all heard the expression sex sells.
could it be bc sells also?
30 cal is good when wind is blowing I have I 308 3006 and 300wm
I favor 185gr lapua for longrange with 300wm my 3006 is my only rifle
shooting 3 168 match king making 1 hole at 100 yards but nowdays
with cost goin up it is good to have 6mmbr low recoil and low cost reloding
ultra accurate best so far is half inch at 300 yards trued rem action 1/8 tvist
kriger 27 inch barrel jevell trigger nightforce 8x32 br scope
Jesus Christ the same yesterday, and to day, and for ever.
Our Lord Jesus said that as it was in the days of Noah and
also as it was in the days of Lot so it shall be in the days...
It's happening again!!! God sent to us His prophet, and His Word
to this generation and we once more are rejecting it as was prophesied!!! ---> As promised, God Sent His Prophet to us!
My question is why compare a 7mm VLD against two 30 cal non VLDs? That is not apples to apples, kind of indy car to mac truck. Big inherent advantage to the 7mm right off the bat.
Plus I have not heard of anyone getting any better barrel life out of the 7mms especially compared against the mag 30s. Throw the 300 WSM in the mix with 210 VLDs and whole new game especially on barrel life. 28-30" barrel and 2850 is the low end and 3000+ is the upper depending on your chamber and barrel and well over 2000 rds is the norm and 4000 rds with IBS winning gun in 2008, which as you know is 2-3x over many of the 7mms.
Recoil, OK, more mass on the bullet the higher the recoil. However, that is only a factor if shooting if shooting NRA LR or Fclass with high number of shots in short period. Non factor in LR hunting.
How does the 7mm VLD compare against say the JLK 210 LBT with its much higher BC (.680/690 BC?), especially at the higher MV of the big 30s?
Part of what I'm illustrating is that there are few very efficient designs in .30 cal (similar to the smaller caliber VLD's). The heavy .30 cal bullets (Sierra and Berger) are made with the same length ogive as the 155's, which is relatively short for a 200+ grain bullet.
One exception is the 208 Amax, which is has a much different (longer) ogive and boat tail than the lighter weight Amax's.
You have a good point about barrel life. It's usually better with the larger calibers, even the magnums when compared to smaller calibers. My point was that to achieve the velocity required to match ballistic performance of the heavy 7mm's, you need to load the .30's real hot (because the bullets aren't as good in .30 cal). Loading anything real hot will reduce barrel life, but it's being reduced from very long, to just acceptably long.
To be self-critical...
The biggest problem with my article being on this site is that kinetic energy, momentum, or any measure of lethality is not mentioned. The article was originally written for Precision Shooting Magazine, an audience primarily composed of target shooters. I didn't really give any thought to hunting applications where bullet weight and energy are important. This IS where the .30 caliber shines. Despite having less-than-optimal bullets, the big .30 caliber magnums carry a lot of energy and momentum due to their mass. It takes a very long distance for the external ballistic efficiency of something like a 7mm 180 VLD to 'catch up' to the energy of a .30 cal 210 VLD.