https://www.youtube.com/watch?v=KEJr54GJob4


http://www.hornady.com/support/heat-shield/

So, it seems the tip melts and changes the BC as the bullet flies.

Inderdasting.

I'd be interested to hear what Bryan Litz or Nosler has to say about this melting thing.

Certainly, this must have been considered and this possibly tested by the initial "plastic tip" bullet makers.

This is also a potential problem with lead-tip bullets, but so far as I know, the lead tips do not melt in flight.

I guess that's why the matchking hollow points were always more consistent than the A-Max on the 1,000 yard range.

The problem with this "revolutionary" product is that it's only a meaningful improvement for about 2% of the shooting public, experienced shooters specializing in long range marksmanship. For all I know it's as good or better than claimed, but let's not kid ourselves about it being a meaningful improvement for the 98%.

Every once in a while when shooting 22 spire lead tip bullets from a 9 twist barrel I get lead gray comet tails on paper. The holes are round enough but dust comet tails appear. All the holes from that loading are the same. I always felt that the bullet temperature, centrifugal force and impact energy release were the culprits. Has anyone else had this happen? and what conclusions, if any, did you come up with? roger

Hornady is pushing this as the next big thing?

It sounds like they had a problem, that they knew about, and took all these years to come up with a fix for it.

quote:

Originally posted by Lapidary:
Hornady is pushing this as the next big thing?

It sounds like they had a problem, that they knew about, and took all these years to come up with a fix for it.

My first thought as well, but they claim everybody else's polymer tips melt as well.

Sounds like Remington had the right idea with "Bronze Points" way back when.

At what velocity does friction melt polymer?

quote:

Originally posted by wildcat junkie:
Sounds like Remington had the right idea with "Bronze Points" way back when.

At what velocity does friction melt polymer?

I shot a lot of bronze points at one time in my life never did notice and melting of the tip during flight.

Never noticed these signs of melting,just plastic tips breaking/galling apart in the magazine (Nosler Accubond).

Hornady tells us they were using plastic tips that would melt from air friction at high velocity. The obvious fix is to use a substance with a higher melting point. Duh. But instead of saying they have corrected a design error, Hornady tells us they have invented some sort of wonder Heat Shield tip. How Hollywood is that?

I was eating some breakfast sausage made from a deer shot with a Ballistic Tip. I chomped down on something hard, spit it out thinking the processor got some bone in the mix. It was a weird looking piece of green plastic. Took me awhile to realize it was the tip of the bullet, must have gone thru a grinder, hence the funny shape.

Friends-

This is an interesting concept but, as has been pointed out the thesis has some interesting implications. For example, everyone who made bullets with poly-carbonate tips failed to heat test their bullets, Hornady included and these have been around for what, 20 plus years?

Another, an old sage shooter once told me that tip deformation on lead tipped spitzers was a lot of hooey because, the lead tips melted in flight (goes to figure, Barsche's lead comets).

And, hollow point bullets would be more accurate at long range due to lack of tip deformation and a more aerodynamic profile.

quote:

Originally posted by bartsche:
Every once in a while when shooting 22 spire lead tip bullets from a 9 twist barrel I get lead gray comet tails on paper. The holes are round enough but dust comet tails appear. All the holes from that loading are the same. I always felt that the bullet temperature, centrifugal force and impact energy release were the culprits. Has anyone else had this happen? and what conclusions, if any, did you come up with? roger

With my 26" barreled 222 model 722 I can push Hornadys 50gr sxsp to 3400fps (1 in 14 twist)
3400x720 / 14 = 174,857 bullet rpm

With my 223 Model 700 HB I can see a gray streak all the way to the woodchuck at 3300 fps (1 in 12 twist)
3300x720 / 12 = 198,000 bullet rpm

With my 26" 223 Model 70 Winchester the bullet will come apart at 3300 (1 in 9 twist)
3300x720 / 9 = 264,000 bullet rpm

I wrote a letter to Hornady about 20 years ago and I think they said the sxsp was at its best around 180,000 rpms. The bullet was meant for the 222 14 twist.

I have a Model 700 22-250 14 twist, the sxsp comes apart at 3900fps
3900x720 / 14 = 200,571 bullet rpm

Hornady's sxsp and Sierra's blitz projectiles were developed for 222 velocities with a 14 twist (Blitz projectiles, not the tipped blitzkings)

quote:

Originally posted by wildcat junkie:
Sounds like Remington had the right idea with "Bronze Points" way back when.

At what velocity does friction melt polymer?

It would depend on the twist...on or before 307,440 rpm's

Bartsche should try pushing a 25-06 as hard as it will go with light varmint bullets...

Blue grey contrails are one thing, bullets turning into airborne puff balls 50feet from the muzzle are a possibility...

quote:

Originally posted by Allan DeGroot:
Bartsche should try pushing a 25-06 as hard as it will go with light varmint bullets...

Blue grey contrails are one thing, bullets turning into airborne puff balls 50feet from the muzzle are a possibility...

Allan, In 1966 I built a 6.5 X .284 on an Arasaka with a high chromium content barrel, fast twist. With a near full case of 4831 Mil. surp. Every 140 grain bullet ( probably Speer and Sierra )showed up on paper at 10 yards as though I were shooting # 12 shoot or finer.
roger

I was reading today that the "tip melting" (according to Hornady) was restricted to very high BC long range bullets (6.5 mm caliber or greater) and only after 350 to 400 yds.

This seems weird to me.

I checked Litz's G7 BC data and I didn't detect a consistent drop in G7 BC's from higher to lower velocities for either plastic tipped or non-plastic tipped bullets.

If Litz is calculating G7 BC at various points along the bullet path as the bullets travel down range beyond 350 yds and slow down, then - if the tips are melting - the G7 BC should be declining as the bullets grow more blunt tipped and less aerodynamic.

I'd like to hear what Litz thinks of this new tip technology and what other manufacturers are saying.

I think litz is/was measuring BC with a few microphones. This gives you discrete time/distance points that you can try to fit up to a trajectory and back out a BC. It seems the breakthrough has come with the radar rigs, where the velocity can be measured for the whole trajectory. In this case they noticed that a single BC didn't seem to match up with what they were seeing, but a bullet that started with one BC and changed to a different BC would.

http://www.hornady.com/assets/...echnical_Details.pdf

Interesting they tested Nosler/Berger/Barnes bullets as well...

Hornady has done a pretty good job of making very good game bullets for quite a long time,and they have all been accurate as far as I know, as are most of today bullets, and the bullet companies today do test their bullets with a lot of sophisticated equipment and even on game prior to production..

I think I will just try the bullets on targets and game before I make any comments on something I've not tried as opposed to basing my opine on guess and by gosh, which is what I'm hearing??

As to the Bronze Point mentioned and for what its worth to those that may have a few of them stashed away. I used them for awhile on game, but they were not particularly accurate and were either chicken or guts and feathers on deer size game, and worthless on elk...They either killed deer like s lightening strike because they exploded like a bomb inside the ribcage or they blew a crater the size of plate on the shoulder and you either got lucky and recovered the deer or you lost it. At any rate they don't make them anymore and they are not missed. Today with bonding and/or partitions they would be About like a Accubond and work just fine.

Until other manufacturers and Bryan Litz comments and/or replicates these results, I remain neutral and uncommitted regarding the veracity of Hornady's findings.

Please note - regarding the link posted above - that Dave Emary is Chief Ballistic Scientist at Hornady® Manufacturing and clearly has bias toward his company's products.