azrocks
Member
- Joined
- Jun 28, 2016
- Messages
- 659
It's also weight distribution, and consistency of the heel of the bullet that determines accuracy.
Sierra bullets are more accurate for a reason. Attention to details, quality materials, and near perfect execution of construction. Exactly why they're more expensive. You do get what you pay for.
Re: hollow points; By moving the mass of a bullet away from the center of axis, it improves the gyroscopic stability, and hence accuracy. Also by moving center of gravity rearward, it also enhances stability and therefore accuracy. It's the back of a bullet that steers it. If it wobbles, it'll veer off like a Greg Maddox curve ball. Only never the same way twice... Try playing with a child's top. Notice that it's wider towards the base (top). Small point on bottom to reduce contact surface drag... so it will spin longer, similar to hollow point rifle bullet, only also factoring in frontal drag from wind resistance.
Sierra has never pursued the pistol bullet self defense market, because thin jackets and soft lead cores make it easier to make an accurate bullet, but such tends to over expand and limit penetration. Not in vogue these days.
If I'm looking for an accurate jacketed pistol bullet, I use Sierra. Shot a couple of national records with them and won many matches.
For an accurate self defense load, controlled expansion; give me a Hornady XTP or Speer GoldDot.
I didn't imply that any of the characteristics of the 9mm bullets were unique to the 9mm. The .22lr does exactly the same thing. Ditto 7.62x51, only at dramatically longer distance. Just that it can happen before reaching a 50yd target with undesirable results.
When bullets go transonic, a multitude of things happen. Drag increases exponentially, also increasing wind drift, and instability. Meaning accuracy (actually precision, but also predictability of point of impact) becomes random or worse. And it's not just going transonic; witness the .38spl with 148gr wadcutters at 775fps m/v. Beyond 60yds, the bullets slow below the stability threshold for the typical 1/ 18-3/8" twist of a S&W revolver or 1/16" twist of a custom Douglas PPC match revolver barrel . Often even 50yd targets show wadcutters starting to "tip" or keyhole. By 85-100yds, the bullets are tumbling and won't reliably hit a silhouette target. But at 50yds, they'll shoot 24rds under 2".
Welcome to the wonderful and wacky world of pistol competition shooting.
Thanks for this great explanation, sir.