Originally Posted by
Big Z
They seem to have a good rep on LRH. I would expect the BCs using the G1 standard projectile (short, flat based, spire point) to get more and more inaccurate the higher (for caliber) they were. Just seems like that's how it would be with the bullet becoming less and less similar to the G1SP. But the G7 standard projectile (long, boat tailed, spire point) being used as a comparison is a more accurate BC for bullets similar to this design. You can search online for G7 calculators. The higher BC bullets would always get my vote for long range shooting, cause it's always windy here
The longer bullets just need a faster twist to be stabilized correctly, which is why most rifles won't favor the heavier bullets, especially when they are long match bullets with high BCs. Right?
It's not a matter of just adding twist to stabilize the extra long bullets. If it was, ever 1000 yd BR competitor would be using bullets with the highest BCs they could find. They aren't. Most of those super long bullets don't shoot well--at least when you apply 1000 yd BR accuracy standards. The 7mm 180s and .308 240s are not the bullets that win matches, even in windy Tucson.
Further, the faster you spin a bullet, the more chance you have of seeing flight patch departures based on the lonitudinal axis not being in line with the rotational center of gravity. That's why target shooters tend to use the slowest twists that will properly stabilize the bullet.
I'm sure the G7 is a good tool for
predicting BC, IF the bullets aren't wobbling when they exit the muzzle. However, the actual BC of each bullet will vary based on the barrel it's shot from, and is often (mostly?) not based on what the paper calculations show.
Then again, you may need to be shooting 3-4" 5-shot groups at 1000 yds for this effect to be noticable. In a LR hunting rifle it probably doesn't matter as much.