30 06 - 130 gr bullet

[Treeman]

I got into a argument with a farmer - "this is how we do it done it and its the best way"
The guy hunts kudu with a .243 and argues that caliber does not matter, only shot placement. This guy also hunts with a 30 06 using 130 gr bullets because it shoots flatter.
To what range would a 130 gr bullet beat a 165 gr bullet and then at that range would that 130 gr bullet still have enough energy ?

[Tripodmvr]

 

[Tripodmvr]

Thre is 2 inches in the two bullets above. The momentum at range is what I would look at.

[Ds J]

How does that accord with Gerrie Schultz's doctrine that lighter bullets do better?

[Treeman]

How does that accord with Gerrie Schultz's doctrine that lighter bullets do better?

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Lot faster bullets.
I think energy is velocity x weight = kinetic energy ? So if the bullet gets to have a higher velocity gained by reduced weight then it can equal or exceed the slower heavier bullets energy. Its all a trade off.

Gerry's main thing was propriety coatings that reduced barrel friction, which reduced start up pressures on firing. By lowering or sometimes almost removing resistance on ignition,the first few millimeters, the pressure spike that blows chambers up was flattened out and loads could be increased which then cheated a bit on the velocity gains achieved by the lighter bullets, making them even faster. This higher than uncoated bullets velocities then delivered even flatter shooting bullets with a slight gain in energy over uncoated bullets.
It is believed that the reduced barrel time and reduced chamber flame, pressure time also reduced throat burn out.
 

[Treeman]

Thank you Oom Drie, not much gained or lost out to 300 yards it would appear. I wonder how much  bullet penetration would differ when measured in actual media, a lot more than what it does in flight I am guessing.

[Tripodmvr]

Energy = 1/2m(v squared). The higher speed is thus exaggerated by the speed squared. This is not what kills, but mostly explodes the area hit by a bullet at high speed

Momentum = mv Gives an idea of penetration potential. Heavier bullet makes the product bigger, whilst speed also plays a role

SD = bullet weight in pounds divided by diameter squared. Longer bullet per fixed diameter is heavier and thus helps penetration

The fact that a monometal bullet does not break up, is longer due to the lower specific mass of copper and can then be driven faster ensures adequate penetration and damage to the internal organs.

[janfred]

Also, the monometal bullets needed a higher impact velocity for adequate expansion.

The coatings may help in reducing the inbore friction but this then reduced velocity, requiring more powder to offset the loss of velocity. I.e. to get the speed you need pressure; coating reduce the pressure therby the temperature; less pressure gives less speed; you need to add more powder to increase the pressure; higher pressure give higher speed but also higher temperature. Zero sum game at the end of the day.

In practice there is no evidence that barrels lasted longer when using GS Custom bullets as opposed to normal jacketed bullets.

[Treeman]

In practice there is no evidence that barrels lasted longer when using GS Custom bullets as opposed to normal jacketed bullets.

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Simply because reduced pressure = reduced delivery, therefore pressure needs to be upped to gain the potential velocity available which then takes you back to same pressures, but for higher velocities.
To be fair Gerrie does quiet openly admit to this and states somewhere, " or you can just shoot these bullets at standard velocity and gain / save barrel life"
No free lunch's were ever implied by the man.

[janfred]

Gerrie might not have implied it, but most people giving advice on how to load them did.

That said. The main reason people are advised to go one weight class down when changing from lead core to monometal is that some rifle barrels do not have a fast enough twist rate to stabilise the longer bullets. Also as mentioned previously you need a higher impact velocity for adequate expansion when shooting the GSCustoms. This is where Gerrie's "faster is better" comes from.

The molycoating was necessary to reduce the copper fouling caused by his patented "micro grooving". The other results were just side effects.

On a side note. Using coated bullets does save the throat a bit from advancing, but does not reduce the damage (fire cracking) caused by heat.

[Treeman]

Gerrie might not have implied it, but most people giving advice on how to load them did.

That said. The main reason people are advised to go one weight class down when changing from lead core to monometal is that some rifle barrels do not have a fast enough twist rate to stabilise the longer bullets. Also as mentioned previously you need a higher impact velocity for adequate expansion when shooting the GSCustoms. This is where Gerrie's "faster is better" comes from.

The molycoating was necessary to reduce the copper fouling caused by his patented "micro grooving". The other results were just side effects.

On a side note. Using coated bullets does save the throat a bit from advancing, but does not reduce the damage (fire cracking) caused by heat.

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see you know your shit ey !