Bullet tips melt! Now what?

[Engineering101]

I subscribe to Shooting Times. When I got the February issue I noted right on the cover this big picture of the new Hornady ELD-X and the words "Game-Changer". I read both articles carefully. Needless to say, afterword I was depressed when I looked over at my $5,000 stack of bullets and realized many of them have tips that are Delrin and will melt at some distance downrange depending on the ambient temp, altitude and velocity. For a while I talked myself into thinking that my Accubonds, AMAXs, Scirrocos, VMAXs and TTSXs would be OK somehow. Exactly how I wasn't sure. Unfortunately I have evidence that shows a tip that melts is a problem.

I have a target (a white piece of paper 5 feet X 1.5 feet) at which I fired 3-shot groups at 200, 300, 400 and 500 yards while aiming at the same spot at the top of the target and with no adjustment to the scope. The difference in vertical in the groups shot at 400 and 500 yards is where my suspicions started. At 400 yards the 3-shot group showed a 1 inch vertical dispersion and at 500 yards it was 3.5 inches. Two of the 3-shot group dropped 47.5 inches and were an inch apart horizontally. One of the shots printed with 44 inches of drop above the first two. This rifle is way too accurate for that to happen. Clearly the tips on the first two melted, degraded the BC and they dropped 3.5 inches more than they should have. The rifle is a Savage Model 12 LPV in 223 Rem, the bullet a 53 grain VMAX. Since this is a LRH forum and people tend to want to shoot game out past 500 yards on occasion, I'm saying this is a problem. How do you shoot accurately when you don't know if you are going to have a degraded BC or not? (Berger - count your lucky stars!)

Anyway, I've decided to use bullets where the tips don't melt, Bergers, Sierra Game Kings, ELD-Xs. To prove there is life after Delrin I grabbed some of my old Game Kings and stuck them in my 270 WSM. Not a bad group for an old out of fashion bullet. I've got some 160 grain Nosler Partitions that work pretty good too. Long live lead!

So what say you? Is this a problem for all bullets with Delrin tips?

 

[Buttermilk]

Lead tips might melt too.

Pure lead melts at lower temps than the delrin tips I believe.

 

[tbrice23]

101,
Why wouldn't the delrin tips not melt at the same rate?
How is your ES and SD on your load?

 

[Engineering101]

buttermilk

You are right and wrong. Delrin melts around 400 degrees F and lead at 621 degrees F. But, at velocities over 2,100 fps, stagnation temperatures at the bullet tip are above 700 degrees F. So, lead could melt too but it is better than Delrin by quite a bit. By comparison Hornady's new polymer used in the ELD-Xs melts at 700 degrees F and they say it won't have issues (melt) unless fired at velocities above 3,400 fps. All of that doesn't quite add up but that is what the articles in Shooting Times indicated. So who really knows what is going on here? Not me.

 

[Engineering101]

tbrice23

I figured that 500 yards was about the transition point in melted versus not melted based on what Hornady found and indicated in the Shooting Times article. Thus one of the bullets might have stayed together a little longer than the other two - especially if it was fired out of a cold bore and the others were a little warmer to start.

The last time I checked ES of my 223 load it was 19 fps. Don't know SD.

 

[Rancid Crabtree]

I just dug a hole and buried all of of my "old bullets". The local monument company is going to make me a tombstone.

"AMAX, a good friend. He will be missed. Burned his tip and went to hell".

In honor of my old friend, I've switched to Bergers and Sierra's. No Hornady bullet will ever touch my lands and grooves again.

 

[7mmShooter]

Maybe that's why Sierra went with Acetal Resin for their Tipped Match Kingsgun)

 

[Engineering101]

Acetal Resin is Delrin.

 

[Buttermilk]

buttermilk

You are right and wrong. Delrin melts around 400 degrees F and lead at 621 degrees F. But, at velocities over 2,100 fps, stagnation temperatures at the bullet tip are above 700 degrees F. So, lead could melt too but it is better than Delrin by quite a bit. By comparison Hornady's new polymer used in the ELD-Xs melts at 700 degrees F and they say it won't have issues (melt) unless fired at velocities above 3,400 fps. All of that doesn't quite add up but that is what the articles in Shooting Times indicated. So who really knows what is going on here? Not me.

Correct...

I confused the new tip melting point with the older tip melting point. Pure lead melts at 621.5 F but some of the lead in some bullets is likely to a lead alloy and thus have a higher melting point.

I recall Hornady's technician stating in one of their videos that the tip degradation was less than one pixel on their camera they were using to try to actually photo the tip deformation due to melting. So essentially, even Hornady can't produce video/photo proof of the tip melting in flight.

 

[7mmShooter]

Acetal Resin is Delrin.

Oops, learn something new every day

 

[Bravo 4]

I gotta ask and it's gonna sound smartass but it's to get you thinking: how did they shoot at that range before you read that article?
You may have just had a small flyer, if you even want to call it that as you're still well under moa. You say your velocity spread is 19, was that worst case scenario tested over a large number of rounds? Or just a small batch?

 

[Engineering101]

bravo 4

I appreciate your critical thinking in this instance but there are a couple of other factors I didn't mention which points to a guilty bullet.

1) The percentage amount of degradation in BC indicated on my target with the 53 grain VMAX is suspiciously similar to what Hornady found in the Doppler radar testing. Kind of odd that you would get a flyer that just happens to match the Hornady data.

2) I took that gun with the VMAXs after some prairie dogs last Spring and it was lights out until about 400 yards. Past that it got really inconsistent. This gun will put 10 into a 1 inch square at 200 yards so it was might suspicious that it would fall apart at 400+ ranges.

My nephew was using the same bullet and he experienced the same thing. We were both scratching our heads and never did figure out what was going on. But this new info on melting tips is one possible explanation. I've since added a 22-250 fast twist running 80 grain Match Kings (all metal) which according to the theory should not have issues past 400 yards so we will see what happens this Spring.

As to ES in velocity - common sense tells me that 19 fps (or twice or three time that) out of 3,000 fps is not going to make a significant difference in bullet tip heating so I don't look to ES as a factor.

 

[Bravo 4]

bravo 4
As to ES in velocity - common sense tells me that 19 fps (or twice or three time that) out of 3,000 fps is not going to make a significant difference in bullet tip heating so I don't look to ES as a factor.

You see, that's where you messed up. You threw common sense into it!

When I mentioned ES it had nothing to do with with difference in bullet tip heating or degradation from such phenomenon. I was refering to the difference in POI for different bullets with different velocities at extended ranges. I haven't run any numbers but I bet an ES for that errant rount (if it was errant at all) of around 40 could change the POI a couple of inches at 500 yards.
One group proves nothing, and like I stated previously- that's a good group! I would be happy with it, and sure wouldn't look at my $5,000 pile-o-bullets and frown upon them. I would just go shoot the crap out of them.

I may sound argumentative, and maybe I'm just playing the role of the 10th man. However, I have shot some light to medium weight for caliber Amax/SST/Ballistic tips way faster than 3,000 fps and never had a problem to some very far distances.
People have been doing it for decades. I'm not saying Hornady is right or wrong, or it's a conspiracy to sell more bullets. I'm saying that it hasn't been a problem and now all of a sudden it is!?
Maybe I'm just a little on the skeptical side. I'm liking their new bullets just for the fact that it seem like part of the evolution of performance, possible better external and terminal ballistics. So what's not to like about them? Those two probabilities alone would have me sold.

 

[KillerBee]

Anybody notice any melting with the Nosler Trophy Grade ABLR's?