Cold temp affecting terminal performance of plastic tipped bullets

[WildRose]

no I haven't but I do know the melting points of metal and from the video they presented, their claims (to me) from what I've found are false.

Why have you been to 3000fps?? is it hot?? did you melt? or do you just believe everything you read on the internet. I see where they are coming from but the ammout of time spent at the temp that melts lead from "their" video.... not gunna happen. If it was sooooooo bad why are all there bullets not made that way? why would they sell cheap inferior bullets that melt away to nothing when we shoot them and like I said in the beginning "I personally"

Lead melts at about 620, zinc around 790 so even if we're talking about a lead/zinc alloy the tips will most certainly be exposed to enough heat in flight to melt.

The plastics that have traditionally been used for ballistic tips melt at about half of that.

Hornady did extensive research to see why the BC's of the ELD's were dropping faster than predicted and determined it was the tips heating up to the point that they were quickly eroding in flight. They also followed the same process with lead tipped bullets and of course got the same results only to a lesser degree.

It should be no surprise to anyone that high temps and extreme friction will quickly erode away and/or melt away soft metals like lead and plastics not specifically formulated to withstand temp's in excess of 800 degrees.

Note, while I've been a lifelong fan of Hornady I was terribly disappointed in the ELD-X when I learned they chose not to make it as a bonded bullet and quit shooting them pretty quickly after first trying them due to bullet separations.

 

[WildRose]

Pretty cool video

1 million FPS? Has to be frames per second rather than velocity. Cool video.

 

[WildRose]

https://www.ballisticstudies.com/Knowledgebase/SST+and+Interbond+annealing+tutorial.html

found it

I could see the benefit of annealing the Amax, Interlock and SST but not the interbond.

The bonding process used in making the interbond involves heating the jacket to the point that it essentially solders the core to the jacket which is the same thing that would be accomplished by annealing.

 

[Capt RB]

I could see the benefit of annealing the Amax, Interlock and SST but not the interbond.

The bonding process used in making the interbond involves heating the jacket to the point that it essentially solders the core to the jacket which is the same thing that would be accomplished by annealing.

I was of the understanding that annealing was done to get a better expansion at longer distance/lower velocities. The bonding agent used for bullets could be heat activated from firing. Similar to what is used for nail guns for specific applications in coastal hurricane prone areas.
Some of the heat activated adhesives and other agents are amazing. Applications at the nano level with mind boggling mechanical properties.

 

[WildRose]

I was of the understanding that annealing was done to get a better expansion at longer distance/lower velocities. The bonding agent used for bullets could be heat activated from firing. Similar to what is used for nail guns for specific applications in coastal hurricane prone areas.
Some of the heat activated adhesives and other agents are amazing. Applications at the nano level with mind boggling mechanical properties.

That was my understanding as well with the goal being to soften the copper from tip to ogive to give that result. That would take some real talent with the plastic tipped bullets to avoid melting it in the process

 

[RockyMtnMT]

Interesting thread. We were just having this discussion the other day. We have not tried to test it yet and I also have nothing other than a feeling that we are seeing variance in terminal performance based on air temp. My suspicion is just speculative at this point but I think the OP is onto something. When I get a chance I am going to just do a simple test by shooting cold and hot bullets into media and see if I can observe a difference in bullet deformation. We have tested bullets on hot summer days vs winter and I think we see better results when it is hot. Have not paid specific attention to it but as I recall back on test sessions I think there is something to it.

Steve

 

[Canhunter35]

Interesting thread. We were just having this discussion the other day. We have not tried to test it yet and I also have nothing other than a feeling that we are seeing variance in terminal performance based on air temp. My suspicion is just speculative at this point but I think the OP is onto something. When I get a chance I am going to just do a simple test by shooting cold and hot bullets into media and see if I can observe a difference in bullet deformation. We have tested bullets on hot summer days vs winter and I think we see better results when it is hot. Have not paid specific attention to it but as I recall back on test sessions I think there is something to it.

Steve

That's exactly what I've observed. If you do a test, I would like to hear the results.

 

[4xforfun]

For those of you saying lead doesn't melt when fired out of a rifle. Riddle me this why do alot of my bullets go "poof" after 25 yards?. If the lead core wasn't actually melted, the core would keep going and impact somewhere around the target at 100 yards. A large percentage of the time while prairie dog hunting nothing makes it a hundred yards.

 

[bpcrshooter]

https://www.hornady.com/assets/site/hornady/files/resources/ELD-X_ELD-Match_Technical_Details.pdf

https://www.ballisticstudies.com/Knowledgebase/Berger+VLD+annealing+tutorial.html
a couple more

"Lead melts at about 620, zinc around 790"-Wildrose
I dont want to start a ****ing match, Im just here to learn, if we read the story from Hornady the say that the "new" heat shield tip is made at a temp of 700F, lead/tin 20-1 melts @ approx 720F, so would the poly tip having a melting/flow point of 700 change as much as lead??? does Hornady use straight lead?? if so, is the 80deg (620-700) going to make that big of a difference??

 

[Pdvdh]

I could see the benefit of annealing the Amax, Interlock and SST but not the interbond.

The only bullets that are suitable for annealing after manufacture are the Berger style bullets with the hollow copper jacket tips.
It's impossible to anneal copper jackets in direct contact with lead or plastic, without melting the lead/plastic.
Annealing Berger-style bullets is an effort to help enable expansion at reduced/lower impact velocities, whenever I've read about it.

 

[Howland]

For those of you saying lead doesn't melt when fired out of a rifle. Riddle me this why do alot of my bullets go "poof" after 25 yards?. If the lead core wasn't actually melted, the core would keep going and impact somewhere around the target at 100 yards. A large percentage of the time while prairie dog hunting nothing makes it a hundred yards.

I know that when I was developing a load for my 788 in .22-250, some loading manuals said that light hollow points pushed close to 4,000 fps can expand as soon as they leave the muzzle on contact with air. That could explain what you've observed.

You said prairie dogs so I'm assuming a varmint cartridge. What type of bullet and do you know what the muzzle velocity is?

 

[WildRose]

I know that when I was developing a load for my 788 in .22-250, some loading manuals said that light hollow points pushed close to 4,000 fps can expand as soon as they leave the muzzle on contact with air. That could explain what you've observed.

You said prairie dogs so I'm assuming a varmint cartridge. What type of bullet and do you know what the muzzle velocity is?

We had just that problem with our first 17 rem and my .220 Swifts when pushed at warp 9.

You'd see one puff of smoke at about 25-50yds as the jacket shucked, then another at 50-75yds when the lead just disintegrated.

We went to the original Barnes X to solve the problem in the 17 and I just backed off of the Swift a bit so I could keep shooting conventional bullets as that was all that was available locally at the time.

 

[4xforfun]

I know that when I was developing a load for my 788 in .22-250, some loading manuals said that light hollow points pushed close to 4,000 fps can expand as soon as they leave the muzzle on contact with air. That could explain what you've observed.

You said prairie dogs so I'm assuming a varmint cartridge. What type of bullet and do you know what the muzzle velocity is?

Actually no...it was my 6-47L with an 8 twist trying to shoot the 87, 75, 65, and 58 grain V-MAX. The tube has about 1500 rounds with the 105/108 Bergers @ 3150. NONE of the 87 grain and under VMAX bullets made it to target during load development. MOST of the 70 grn Balistic tips make the trip. ALL of the 105 class bullets make the trip in ALL of my 8 twist 6mm's.

I didn't try them, but I am sure that one of my 8 twist Dashers with around 2200 rounds of 105 class bullets at around 3050 would explode everything under 87 grains also.

I am sure that something with a thicker jacket would help.

Also, there is a reason the Berger came up with an entire new line of TARGET bullets...to help with bullets comming apart.

Tod

 

[Varmiter71]

The RPM's of the bullet makes a big difference on blowups and they blowup from the base.
Reading this article has made me wonder about bonded bullets with the heating in flight. Does this affect the bonding properties