Are bullets the wrong shape?

[johnmventers398]

i have been looking into aerodynamics a little.. it would apear that external balistics wise we shoot bullets backwards...
i understand safty concerns with split cases n such but what about short teardrop shaped light weight varmint rounds that would take the presure relitavly evenly accros the tail.

john

 

[Berger.Fan222]

I've loaded bullets backward from time to time. BCs are horrible. Brush deflection is much reduced. You can also use a center drill in the exposed lead back side of an FMJ and make a bullet that will expand at subsonic velocities. Also works when you have a bunch of pointy bullets and need to shoot a 30-30.

Any way you slice it, it's a short range proposition.

 

[Sniper338]

Pretty sure bullet manufacturers are way ahead of the game vs your thought haha.

 

[SheepDog]

A double ended spitzer or spire point would be the "most" aerodynamic but it is hard to load and shoot accurately unless you added a bearing surface to the middle. It would have to use a very tight twist and so the construction would have to be stronger.

 

[Catfur]

i have been looking into aerodynamics a little.. it would apear that external balistics wise we shoot bullets backwards...
i understand safty concerns with split cases n such but what about short teardrop shaped light weight varmint rounds that would take the presure relitavly evenly accros the tail.

john

Look more, the most aerodynamic shape at supersonic velocities is the Sears-Haack body, which is long and pointy (on both ends). Low drag bullets mimic this shape to the extent possible (a point on the back is not really practical for a bullet).

 

[snert]

If I load a bullet pointed on both ends, does that mean that I can begin to measure to the lands from the land bearing point on both ends and double my accuracy?

 

[Ned Ludd]

Look more, the most aerodynamic shape at supersonic velocities is the Sears-Haack body, which is long and pointy (on both ends). Low drag bullets mimic this shape to the extent possible (a point on the back is not really practical for a bullet).

I understand what you're saying here, but it actually might be practical if some kind of a flat-ended sabot was used that could accommodate the rearward point and provide a flat base while in the barrel, and fall off after leaving the muzzle.

 

[spclark]

I don't see anybody supergluing two flat-base 55 grain 6mm's doing better than the 105's I shoot....

 

[Catfur]

I understand what you're saying here, but it actually might be practical if some kind of a flat-ended sabot was used that could accommodate the rearward point and provide a flat base while in the barrel, and fall off after leaving the muzzle.

It's more a stability issue, as noted above, people do load bullets pointy end backwards. The longer a bullet is, the less stable it is, thus the faster it must be spun.

 

[dcali]

Short answer: No, they're the right shape for a lot of reasons.

 

[johnmventers398]

Very intersting replys. it seems to me, that some double ended bulles have been tested but they clearly were a failure as its not the norm today.. I have a good understanding of why bullets are the shape they are for the reasons I first pointed out in the O.P ammong many others. Just think thogh.. if someone did come up with a practical way to load these, the long range game would change! Think of the max effectav ranges!!
I feel somewhat of a new obsession coming on.. I have already been playing with some shapes in a wind tunnel and have some ideas that i might try and turn in the future.

john

 

[DOGCAPPER]

Someone else loaded bullets backward. Kilmanjaro Bell. (sic) Killed a bunch of elephants with a 7mm Mauser.

 

[johnmventers398]

Someone else loaded bullets backward. Kilmanjaro Bell. (sic) Killed a bunch of elephants with a 7mm Mauser.[/QUOTe

I beliv the NAZI's used to fire bullets backwards but had issues of split cases. There is a youtube video doing this and it shows all backward fired rounds split case necks. However, they where very effectave in the destrucktave side.

john

 

[Berger.Fan222]

I beliv the NAZI's used to fire bullets backwards but had issues of split cases. There is a youtube video doing this and it shows all backward fired rounds split case necks. However, they where very effectave in the destrucktave side.

I never saw a split case neck when doing this, but I took care not to push the pressure. I was concerned that the bullet base engaging the rifling might cause pressure to spike, so I kept the powder charges a couple grains below max.

Ball powders work better for charges that nearly fill the case. The bullet point will push ball powders to the side out of the way more easily as the bullet is seated and the point extends down into the powder. Cylinder powders tend to get crushed.

The wad cutter on paper targets is nice. I doubt many would find the accuracy acceptable for match purposes, but it is fine for plinking or hunting to 100 yards.

 

[Berger.Fan222]

Very intersting replys. it seems to me, that some double ended bulles have been tested but they clearly were a failure as its not the norm today.. I have a good understanding of why bullets are the shape they are for the reasons I first pointed out in the O.P ammong many others. Just think thogh.. if someone did come up with a practical way to load these, the long range game would change! Think of the max effectav ranges!!
I feel somewhat of a new obsession coming on.. I have already been playing with some shapes in a wind tunnel and have some ideas that i might try and turn in the future.

john

Interesting stuff. Keep us informed.

I don't take the absence of a product on the market as a technical failure of the idea. Bullet companies exist to make money, and the manufacturing costs of a bullet pointed at both ends are likely much higher than current designs. Large markets willing to pay higher prices for large volumes of lower drag bullets are a relatively recent phenomenon.

The business question is not whether the bullet pointed at both ends will reduce drag and fly straight, but whether it will reduce drag enough to warrant the higher costs and sell in volume at the higher cost.

Of the nose drag, skin drag, and base drag that make up most of the total drag of modern long range bullets, is there really that much to be gained by further reductions in base drag?

 

[Barlow]

A Canadian scientist named Gerald Bull invented a bullet for cannons called a "Base Bleed Bullet". The base of the projectile was hollowed out and a material packed into the base that burned in flight reducing drag on the bullet and greatly enhancing its range. Iirc it was named the "Kalahari Ferrari". Not the same as two points but interesting. He was the inventor of the Super cannon, which eventually got him killed. Barlow

 

[dskogman]

That's where boat tail bullets came from. A long tail has negative effects as well so cutting it off to a boat tail gives most of the benefit and reduces the negatives.

 

[mikecr]

A long base isn't a problem, but less than optimum angle increases drag. So this is easy enough to overcome.
For the increase in base area, and clean muzzle release, some muzzle pressure held lower or bled off just prior to release would solve this. Not a muzzle brake, but an EDM ported bore. Stability with a backwards bullet could actually be so much higher as to eliminate any need for rifling(smooth bore), provided CG is kept before CP(which this design permits potential for).
And bullets themselves do not cause split necks.

 

[spclark]

...some muzzle pressure held lower or bled off just prior to release would solve this.

Maybe why rebated boattails show up every so often?

 

[GerryM]

all bullet shapes are a compromise IT depends on Distance you are shooting.
Bt bullets are good for long range {past 300 yds.
The actual ogive is a different story. for short range 50 to 100 yds blunt bullets seem to shoot very well
Long bearing surfaces are good for rifles with longer throats The sharper point,s need more velocity to become stable.
so you have o choose The ideal shape at the end would be round. But still a choice.
so you pick your shape and be Happy.