Re: Berger Bullets' Move To The G7 Standard BC By Bryan Litz
Do have to take exception to one portion of this piece; the comment about the industry utilizing the G1 drag model simply because it results in the highest numerical values. In other words, a marketing ploy. As long as we have every one's attention here, I'd like to reaffirm the fact that the universal use of the G1 drag model is one of expediancy (okay, laziness) , not a marketing strategy. Until relatively recently, very few shooters had any concept or underestanding of BC. Sadly, based on the Shooting Times comments about the BCs being based the .50 BMG round, many gunwriters still don't. It was nothing more than a quick and lazy way for manufacturers to compare a diverse spectrum of bullets with the minimal amount of work. What is called for here is that each bullet be used with the proper drag model appropriate to that bullet, be it a G1, G2, G5, GL or the G7 or any of several others. As you know (and others should understand), the G1 is not an appropriate drag model for the .30 cal 170 FN for a .30-30. Neither is a G7. I don't have Lowery's text in front of me here, but there is a drag model specific to flat-based, flat (or blunt) nosed projectiles. That's what should be used, but for a 75 yard shot from an iron sighted M94, does it really make a huge difference? Most of the Lyman pistol designs should properly use the GL model, but like the M94 example, we're talking about some pretty finely split hairs here.
Berger has an advantage in this field, in that the vast majority of the line is appropriate to the G7 model. A bit more difficult for a company that produces a range of round noses, flat noses, hollow point pistol bullets, etc.. In that respect, Berger is the perfect company to step up to this particular plate, and I'm truly glad to see you do it here. The time is right; we now have the range of computer programs that make this subject more accessable to a wider range of shooters than ever before. Forums like this allow for a great exchange of info between (frankly) a more advanced group of shooters, than presented by the mainstream gun rags and their more generalized audiences.
I think even with the aforementioned ballistics programs, we're still a long ways off from listing and using the correct drag model/table for each type of bullet. Still, the thorough explanation of the G7, and its applicability to the streamlined BT bullets used in Long Range competition is a major step forward in this regard, and I applaud you and Berger for daring to enter the fray. It's a start, and a damned good one.
Keep it up, Bryan, you're performing a real service here!