Damaged Polymer Tips

[JohnyRingo]

I just recently purchased a Browning X-Bolt Stainless Stalker in a 300 H&H Mag. After going through a box of ammo, I've noticed that the recoil from this gun is damaging the polymer tips on my Accubond bullets. I don't feel like the recoil is that much, but I can't be shooting damaged tips on bullets. Is this the result of a faulty removable magazine or is this common for this rifle in a magnum round?

 

[Colorado Cowboy]

I have the same problem on lead points, have had for years. I just take a knife and sharpen them.

 

[Musket Man]

is it affecting your accuracy very much?

 

[AKaviator]

I read an article a few years back in Hand-loader magazine by a writer who tested bullets with the tips damaged. As I recall, after a lot of testing, he determined that it had little or no effect on bullet performance.

I wouldn't worry too much about it or switch to a bullet type that gives a shorter overall length, non-tipped.

Just my thoughts.

 

[JohnyRingo]

A buddy of mine who shoots a 300 RUM says he seats his bullets long to fill up the magazine as much as possible so that the bullets can't come slamming forward on the recoil. He shoots ELD-X's.

I will experiment on P.O.I. with damaged and undamaged tips to see the difference. It's all about having confidence in your setup.

I guess I can also look into a muzzle brake even though I don't mind the recoil. My Tikka T3 243 doesn't damage the tips.

 

[scubohuntr]

The tips turn to goo before they clear the muzzle anyway.

 

[fackelberry]

I want to disagree with a few statements here, and hopefully give some advice. First you can try seating the bullets out to take up magazine space as long as it's still accurate and doesn't create undo pressures when fired. Or when loading them into the magazine, push them all the way forward where the tips just contact the magazine so they can't slam forward with recoil if it will still properly feed them into the chamber. I had a batch of component accubonds i loaded up a few years back and i noticed the tips were doing the same thing, i used them for practice or fouling rounds as i couldn't count on them to be accurate when the time came. I don't know if Nosler had a bad batch of them tips made or what, but i havn't run into that since then.


As far as the accuracy on the tips being damaged or missing. I don't know how far the writer shot his bullets with damaged tips, but me and a reloading buddy are always messing with stuff like that to see accuracy issues and what might happen if you were hunting and all your tips broke or were damaged. Maybe in his gun they didn't effect accuracy, And depending what he calls "damaged" tips. We cut the tip off completely on some damaged ones to see what would happen at different ranges.We would shoot a 3 shot group, 2 good bullets and 1 bullet with the tip cut off. What we found in OUR rifles is at 100yrds, no noticable difference, but at 200,300 and 400 yards the bullets with the tip cut off hit lower than the other non-damaged tips by a couple inches. The bullet failed to hit the 12"x12" target at 400 yards, it dropped below the whole paper We guessed it dropped over a foot from the other 2 rounds. So better to check your OWN gun with YOUR bullets and not assume it doesn't affect accuracy as some gun "writers" claim it doesn't.

I also don't buy into the melting tip "theory"! Maybe Hornady has had THEIR tips melt, but i have shot Nosler B-Tips since day 1 when they came out in the green and red boxes and Accubonds when they brought those out. Me and a few other hunters have found the tips in and on the hides of some of the animals we have shot. The ones that were intact were not melted at all. Some even looked like you could stuff them back in another bullet and shoot them again. If they were "melting" like Hornady says they are, people wouldn't be getting the benchrest accuracy out of them that they do! It's all about marketing strategies.

 

[scubohuntr]

I also don't buy into the melting tip "theory"! Maybe Hornady has had THEIR tips melt, but i have shot Nosler B-Tips since day 1 when they came out in the green and red boxes and Accubonds when they brought those out. Me and a few other hunters have found the tips in and on the hides of some of the animals we have shot. The ones that were intact were not melted at all. Some even looked like you could stuff them back in another bullet and shoot them again. If they were "melting" like Hornady says they are, people wouldn't be getting the benchrest accuracy out of them that they do! It's all about marketing strategies.

Actually, melting would probably be the best thing for accuracy. They make polymer tips with sharp points for marketing purposes. The most efficient form factor for a supersonic projectile is a parabola, not the ogive most bullets are made with. For subsonic bullets, an elliptical form is best. Neither one is sharply pointed. However, people associate blunt bullets with slow, "brush buster" cartridges, so the public perception is sharp points=accuracy. If you cut the polymer tip off entirely, you create a huge meplat, which sheds velocity very quickly. If the plastic tip melts partially, it will flow a bit (it will still be quite high in viscosity, even when melted) and assume a form dictated by drag, which will be very close to a narrow parabola.

As far as "benchrest accuracy", check around and see how many benchrest shooters are using Nosler Ballistic Tips or Hornady A-Max. I will agree, they are very accurate for a hunting bullet. So are Sierra, and even Speer. Shoot what works well in YOUR gun, and shoot enough to build confidence in your chosen load.

 

[Tim McCoy]

I have a buddy that shoots Nosler BT's, he finds the tips often enough to know they don't melt even to fairly long ranges, at least every time anyway.

As far as pointy shapes for bullets go, last I checked they did that to offer better BC's, both in match styles and hunting styles. Boat tails, and secant ogives are also often used. It's not all marketing hype, but a pointy tip, plastic or not, is a design feature to help the BC, which offers a number of advantages, velocity retention and less wind drift among them. Which is probably why fackleberry found the damaged tip test he did hit lower once ranges stretched out.

 

[shootbrownelk]

I've had damaged tips, lead & polymer in my old .35 Whelen and my .375 H&H. I never noticed any difference and neither did the critters. I wouldn't worry about it.

 

[rammont]

Actually, melting would probably be the best thing for accuracy. They make polymer tips with sharp points for marketing purposes. The most efficient form factor for a supersonic projectile is a parabola, not the ogive most bullets are made with. For subsonic bullets, an elliptical form is best. Neither one is sharply pointed. However, people associate blunt bullets with slow, "brush buster" cartridges, so the public perception is sharp points=accuracy. If you cut the polymer tip off entirely, you create a huge meplat, which sheds velocity very quickly. If the plastic tip melts partially, it will flow a bit (it will still be quite high in viscosity, even when melted) and assume a form dictated by drag, which will be very close to a narrow parabola.

As far as "benchrest accuracy", check around and see how many benchrest shooters are using Nosler Ballistic Tips or Hornady A-Max. I will agree, they are very accurate for a hunting bullet. So are Sierra, and even Speer. Shoot what works well in YOUR gun, and shoot enough to build confidence in your chosen load.

Could you provide a source proving you claims about form factor?

All bullets with a pointed tip have a parabolic form, that's not how form factor is defined.
The ogive is the curve of the bullet's surface from the shank to the tip.
A parabola is a curved line with a point to it.

All bullets with a pointed tip have a parabolic shape with a an ogive. The shape of the ogive will exist even if the point of the bullet is large and flat, as long as the bullet tapers toward the tip it has an ogive.

 

[fackelberry]

I've had damaged tips, lead & polymer in my old .35 Whelen and my .375 H&H. I never noticed any difference and neither did the critters. I wouldn't worry about it.

Not all guns will react the same with damaged tips. If it was a tip that was chipped or flattened a little it may not affect accuracy to any noticable amount. But i was showing what a bullet would do with the whole polymer tip cut off! I also think that the big slower guns you have shot Brownelk wouldn't show as erradic signs as my 25-06 or 7mag did shooting lighter bullets faster! And what they would do at longer ranges!

 

[AKaviator]

I want to disagree with a few statements here, and hopefully give some advice. First you can try seating the bullets out to take up magazine space as long as it's still accurate and doesn't create undo pressures when fired. Or when loading them into the magazine, push them all the way forward where the tips just contact the magazine so they can't slam forward with recoil if it will still properly feed them into the chamber. I had a batch of component accubonds i loaded up a few years back and i noticed the tips were doing the same thing, i used them for practice or fouling rounds as i couldn't count on them to be accurate when the time came. I don't know if Nosler had a bad batch of them tips made or what, but i havn't run into that since then.


As far as the accuracy on the tips being damaged or missing. I don't know how far the writer shot his bullets with damaged tips, but me and a reloading buddy are always messing with stuff like that to see accuracy issues and what might happen if you were hunting and all your tips broke or were damaged. Maybe in his gun they didn't effect accuracy, And depending what he calls "damaged" tips. We cut the tip off completely on some damaged ones to see what would happen at different ranges.We would shoot a 3 shot group, 2 good bullets and 1 bullet with the tip cut off. What we found in OUR rifles is at 100yrds, no noticable difference, but at 200,300 and 400 yards the bullets with the tip cut off hit lower than the other non-damaged tips by a couple inches. The bullet failed to hit the 12"x12" target at 400 yards, it dropped below the whole paper We guessed it dropped over a foot from the other 2 rounds. So better to check your OWN gun with YOUR bullets and not assume it doesn't affect accuracy as some gun "writers" claim it doesn't.

I also don't buy into the melting tip "theory"! Maybe Hornady has had THEIR tips melt, but i have shot Nosler B-Tips since day 1 when they came out in the green and red boxes and Accubonds when they brought those out. Me and a few other hunters have found the tips in and on the hides of some of the animals we have shot. The ones that were intact were not melted at all. Some even looked like you could stuff them back in another bullet and shoot them again. If they were "melting" like Hornady says they are, people wouldn't be getting the benchrest accuracy out of them that they do! It's all about marketing strategies.

I don't recall how far he was testing them out to. He found far more pronounced negative effects when he had a flaw on the base of the bullet. (he intentionally did that)
Although it might be fun to test the effects out to some distant range, I really don't worry about anything beyond 300 yards. I don't shoot any farther than that on game.

 

[fackelberry]

I don't recall how far he was testing them out to. He found far more pronounced negative effects when he had a flaw on the base of the bullet. (he intentionally did that)
Although it might be fun to test the effects out to some distant range, I really don't worry about anything beyond 300 yards. I don't shoot any farther than that on game.

Ya i would like to know the distance he was shooting. And i can see that he would see more effects on the base as the gases produced from firing will push on the base unevenly and cause erradic flight when it exits the muzzle. Kinda like when the crown of a gun has a nick or dent in it right at the opening, the gases escape differently and cause erradic flight. I know the ranges i shot without the tip it was obvious it had an effect. But its neat to try little tests like this under controlled conditions andf know what might happen instead of guessing what may happen in the field if one had to shoot a bullet like that!

 

[AKaviator]

That's why you're likely a better shot than I am!

 

[scubohuntr]

Could you provide a source proving you claims about form factor?

All bullets with a pointed tip have a parabolic form, that's not how form factor is defined.
The ogive is the curve of the bullet's surface from the shank to the tip.
A parabola is a curved line with a point to it.

All bullets with a pointed tip have a parabolic shape with a an ogive. The shape of the ogive will exist even if the point of the bullet is large and flat, as long as the bullet tapers toward the tip it has an ogive.

Mea culpa, I was careless in my terminology. I was referring to a power series curve which looks like a classic parabola, while a parabolic nose is actually only a portion of a parabola rotated about its axis. Most bullets have a tangent ogive nose profile (although it's generally not really an ogive, since it is not a spherical curve, but we'll call it an ogive because everyone else does), blunted to some degree for several reasons: 1. Heat dissipation- a sharp point produces much more friction heating at supersonic velocities than a point blunted to some extent. 2. Durability- pointed tips (particularly in exposed lead) are fragile. 3. Ease of manufacturing- It is virtually impossible to draw a really sharp point, even in a full metal jacket, without variations in concentricity that make it unacceptable for high precision shooting.

The ideal shape for supersonic flight is a Von Kármán curve, a specific instance of the Sears-Haack Series providing minimum drag for a given length and diameter. It looks like a power series curve but is subtly different. Of course, there are tradeoffs. A Von Kármán profile is less efficient at high transonic velocities (~M 1.4) than several other shapes. In the fully supersonic region, it is superior. Since it is not derived from simple geometric shapes, it is a bit more difficult (or was until modern CNC equipment came along) to design and produce.

All that being said, the actual ballistic differences between a really well-designed tangent ogive bullet and a true Von Kármán are very small.

Ashley and Landahl: Aerodynamics of Wings and Bodies, (Dover Publications Inc New York 1985)

Carlo Ferrari: Bodies of Revolution having Minimum Pressure Drag. In: Theory of Optimum Aerodynamic Shapes, ed by Angelo Miele (Academic Press Inc, New York 1965) pp 103–124

 

[AKaviator]

Wow, and I was just now getting a handle on the the differences between round-nose and pointy ones!!

 

[scubohuntr]

The difference at reasonable ranges is much less than trivia junkies like me would have you believe. Decades ago, I had a T/C Contender in .35 Remington that was an absolute tack driver. The best load I ever found for it, shooting MOA out to about 150 yards, was a Sierra 160 gr. FMJRN, seated backwards (base front) over H322. It made for a very accurate and pleasant to shoot (compared to the 250 gr at 2200 fps that would rattle your fillings loose) plinking load. For some reason, the same bullets seated correctly were never better than mediocre. I used to refer to them as boattailed wadcutters whenever someone asked me what I was shooting.