Why Are Hollow Point Bullets More Accurate?

...variations in jacket thickness of .0004 inch--AMAZING!

Edit: Sorry thought this was gd

Article is spot on.  Consistency is the key, and the bases of fmj's can be very sloppy.

Yea, it's how they are manufactured. Technically they aren't hollow point though as they aren't designed specifically to expand. Open top doesn't equal hollow point.

Thanks for the info. I had no idea.  That's why I  come on here for the useful info.

Out to 200 yards the most accurate match-target bullets have flat bases, not boat tails.  Its easier to maintain absolute precision and tightest tolerances with a flat base match fine hollow point design.

For .223/5.56 think Berger 52 grain FB Target.  Probably the most accurate 100-200 yard match target production bullet on the planet.

I always understood hollow point as just a construction term that has nothing to do with performance. Sierra lists the Matchking as a BTHP because that's exactly what it is even though expansion is not a criteria of its design.

Nobody ever gets this right. The hollow point doesn't make them more accurate. They're more accurate for a whole bunch of reasons. The hollow point itself just shifts the center of mass rearward which has stabilizing effects. The reason you find them on target bullets is basically down to manufacturing. If you do a cup and core bullet with an exposed base then you have a big bunch of lead exposed at the base (not great) and the core has to be pointed to begin with to properly fill the cup but those aren't likely to be identically shaped so you get voids and you end up with less consistent projectiles than you could by doing it the other way. If you form the jacket with the tip open and the base closed then you don't have lead exposed at the base and you don't have to use a pointed core or even start with a boat tail jacket so you can just cut lead wire more or less into cylinders and press it in. You can press the core in hard enough to swage the boat tail in to shape too which helps keep the lead touching the jacket. Since the core is just a cylinder of lead, for your trouble you end up with a hollow space in the nose of the bullet which shifts the CG rearward improving flight stability.

The base of the bullet is more important than the point when it comes to accuracy. While this may seem counterintuitive anything traveling at Mach 2 or 3 has a lot of pressure effects that don't seem obvious at first glance.

Open base bullets are by far the worst.

My father has some older .308 hollowpoint hunting ammunition with the lead tip exposed, and a dimple or hole swaged in to promote expansion.

“Open tip” is a more accurate description than “hollow point,” especially when most people think of “hollow point” as an expanding bullet.

It all has to do with how the core goes into the jacket.  A closed tip bullet has the core inserted from the rear, requiring the jacket to be formed around the base of the core.  The punches that do this have to accommodate variations in cores and jackets - and these bases are never identical.

An open tip bullet is made in the opposite way; the core is inserted from the front, then the bullet’s ogive is formed, shaping the core in the process.  Variations in cores and jackets are easier to manage with this method of forming.

Since they start with a jacket that already has the base formed, these “front loaded” bullets have much more consistent bases.  They may not be “identical”, but they are always a lot closer to identical than with “rear loaded” bullets.