What does this mean? Little grey swirls by my bullet holes on target.

[JRS]

Based on a 24" barrel, a bullet traveling at 3000 fps is in the barrel for roughly 1/5000th of a second. Not nearly long enough to melt the lead tip.

 

[LHSmith]

Does this mean I will see red swirls from V-max's, orange, purple, blue, red, green swirls from Ballistic Tips? :

 

[JRS]

Does this mean I will see red swirls from V-max's, orange, purple, blue, red, green swirls from Ballistic Tips? :

Probably ;D After all, polycarbonate melts at half the temperature of lead :

 

[jpretle]

Will you see red, if you wear 'rose colored glasses to?'

 

[243winxb]

Failures have several causes. The most common is produced by the core melting. The core melts because it gets too hot. The core gets too hot because of the FRICTION between the rifling and bearing surface. This has been proven to be the hottest part of the bullet as it moves through the barrel. This area has been shown in high speed, infared images reaching tempuratures at the melting point of lead.

Post #9

We know that the lead melt and that once it does no jacket can take the pressure from a material as dense as lead spinning freely as a liquid at 250,000 RPMs. The key to our solution is to keep the core from melting in the first place. But what about the bullet that has only a slight softening of the core material.

Could a core melt slightly enough that the bullet could hit the target but not where you thought it would? I believe the answer to this question is yes it can.

I know it can. From post # 39 from link. Remember the barrels are not in perfect condition or are very hot and dirty with fouling. http://benchrest.com/showthread.php?49336-Berger-bullet-failure-test/page3

Good Luck.

 

[M14AMU]

Does this mean I will see red swirls from V-max's, orange, purple, blue, red, green swirls from Ballistic Tips? :

No necessarily....but you may not see squat on the target AT ALL if you wind them up too tight! Guys had trouble years ago trying to shoot .30 caliber Sierra 250 gr. HPBT with 1-9" twist! I've seen them totally explode in flight due to structural disintegration of the jacket! :-[ ???

 

[243winxb]

The nose of bullets do not melt...

ok. If you say so.

 

[CatShooter]

The nose of bullets do not melt...

ok. If you say so.

Think about it - if noses melted, no two bullets would have the same BC cuz each would melt differently.... and high velocity cartridges like the 220 Swift, the 22-250, the 264 mag, would be so inaccurate as to be taken off the market before they ever started.

 

[Brians356]

Does this mean I will see red swirls from V-max's, orange, purple, blue, red, green swirls from Ballistic Tips? :

No necessarily....but you may not see squat on the target AT ALL if you wind them up too tight! Guys had trouble years ago trying to shoot .30 caliber Sierra 250 gr. HPBT with 1-9" twist! I've seen them totally explode in flight due to structural disintegration of the jacket! :-[ ???

What you had there was a shotgun. Might work pretty well on Chukar at long range. Hmmm ...

 

[Ackman]

Re: Little grey swirls by my bullet holes on target.

Blowby from a larger than normal groove diameter may let hot gas past the bullet. Powder burns near 5000 F degrees. As the nose of the bullet melts, the air friction will have lead coming off the tip of a spitzer bullet as it goes down range. With this condition, look for a rifle that needs about 10 fouling shots to start grouping. In 243 win. the 85gr didnt keyhole, but some 70gr match bullets did, hitting the 100 yard target side ways. The NRA at the time confirmed this with another shooter having the same problem as i. Rifle was a 1965 vintage Win. M70 heavy barrel i picked up used.

The nose of bullets do not melt...

Even dumber than the nose melting....... Years back on a thread about the radial star pattern seen occasionally around bullet holes. One "expert" claimed it was the lead core melting, then going forward and out through the hollowpoint onto the target. This guy's ah engu-neer with a big overblown website that people actually reference.

 

[dedogs]

Re: Little grey swirls by my bullet holes on target.

Blowby from a larger than normal groove diameter may let hot gas past the bullet. Powder burns near 5000 F degrees. As the nose of the bullet melts, the air friction will have lead coming off the tip of a spitzer bullet as it goes down range. With this condition, look for a rifle that needs about 10 fouling shots to start grouping. In 243 win. the 85gr didnt keyhole, but some 70gr match bullets did, hitting the 100 yard target side ways. The NRA at the time confirmed this with another shooter having the same problem as i. Rifle was a 1965 vintage Win. M70 heavy barrel i picked up used.

The nose of bullets do not melt...

Even dumber than the nose melting....... Years back on a thread about the radial star pattern seen occasionally around bullet holes. One "expert" claimed it was the lead core melting, then going forward and out through the hollowpoint onto the target. This guy's ah engu-neer with a big overblown website that people actually reference.

Many of the "Engineers" that I know don't have any common sense AT ALL.

 

[LHSmith]

Re: Little grey swirls by my bullet holes on target.

Even dumber than the nose melting....... Years back on a thread about the radial star pattern seen occasionally around bullet holes. One "expert" claimed it was the lead core melting, then going forward and out through the hollowpoint onto the target. This guy's ah engu-neer with a big overblown website that people actually reference.

I take it you don't agree with Eric Stecker's analysis in the link referenced in post # 24 above?.....or was this an attempt at sarcasm?

 

[Berger.Fan222]

Based on a 24" barrel, a bullet traveling at 3000 fps is in the barrel for roughly 1/5000th of a second. Not nearly long enough to melt the lead tip.

2 ft divided by 3000 ft/s = 2/3000 seconds = 0.667 milliseconds.

This is a lot longer than 0.2 milliseconds (1/5000th of a second).

Further, the bullet is not travelling at the muzzle velocity down the whole length of the barrel, since it starts at 0 ft/s. In real life, a bullet with a muzzle velocity of 3000 ft/s will spend close to 1 millisecond in a 24" barrel.

 

[Ledd Slinger]

I think deep groove depth, roughness of bore, excessive fouling, tighter than needed twist rates creating high RPM are all major contributors to excessive heat causing jacket failure.

Of course bullet speed plays a part in all that as well. The faster metals grind together, the faster it produces heat.

And you can melt the tip alright. Well maybe not "just" the tip. But I've melted entire bullets "including" the tip.....really sucks when that happens while shooting through a new chronograph... :-[

 

[Ackman]

Re: Little grey swirls by my bullet holes on target.

Even dumber than the nose melting....... Years back on a thread about the radial star pattern seen occasionally around bullet holes. One "expert" claimed it was the lead core melting, then going forward and out through the hollowpoint onto the target. This guy's ah engu-neer with a big overblown website that people actually reference.

I take it you don't agree with Eric Stecker's analysis in the link referenced in post # 24 above?.....or was this an attempt at sarcasm?

Well, I don't believe something just because it's posted on a forum. And when people need to reference what someone else says, it means they have no idea. And in fact...... Mr. Stecker never mentions the bullet tip. There was no attempt at sarcasm.

 

[LHSmith]

No argument about the lead tip, but on page 1 of that linked thread he concludes his testing confirmed that core melting was in fact the cause of bullet failure.

 

[lazyMlazyK]

I know this is an OLD thread, but just reading through it reminded me of a video I saw the other day. Skip to about the 6:20 mark in the video and you'll see the comet tails starting to appear on target. Interesting read, guys, thanks!