Reloading question regarding .30-06 loads and .308 bullets

[stevied]

The higher pressure is not just from reduced case volume.
E=MC^2
Energy = Mass * Velocity squared.
A heavier bullet = increased mass.
So you need to reduce velocity so that the total energy output is the same due to the increased mass. Too much energy and you may create a bomb instead of a safe (for the gun and yourself) projectile.

The question was not what creates more energy but what is the effect of a longer bullet. And a heavier bullet inherently reduces velocity although charge must be reduced as well (e/m)=v. As mass goes down, so does velocity

[rdfact]

The question was not what creates more energy but what is the effect of a longer bullet. And a heavier bullet inherently reduces velocity although charge must be reduced as well (e/m)=v. As mass goes down, so does velocity

Right, but heavier bullets of the same diameter are generally longer, correct?

[vlady]

Right, but heavier bullets of the same diameter are generally longer, correct?

Yes they are

[stevied]

Right, but heavier bullets of the same diameter are generally longer, correct?

Yes, especially non-lead

[ducky_0811]

You have a good manual, read it, get another one, and then a third, and read those too. I'm assuming your in a condor zone or just getting ahead on the lead ban since your using a lead free bullet, if you're not reloading for hunting, a lead bullet is generally half the price of the ones you're using now. I would also second getting the barns reloading manual since their data will be for their bullets.

The increased length of a lead free bullet increases (generally speaking) the bearing surface in the bore as the bullet travels out the barrel, increasing friction and thus reducing velocity. This can create a unique challenge for reloaders without the proper load data from the bullet manufacture. Of course YMMV, just my. 02

[Mr Blu]

You have a good manual, read it, get another one, and then a third, and read those too. I'm assuming your in a condor zone or just getting ahead on the lead ban since your using a lead free bullet, if you're not reloading for hunting, a lead bullet is generally half the price of the ones you're using now. I would also second getting the barns reloading manual since their data will be for their bullets.

The increased length of a lead free bullet increases (generally speaking) the bearing surface in the bore as the bullet travels out the barrel, increasing friction and thus reducing velocity. This can create a unique challenge for reloaders without the proper load data from the bullet manufacture. Of course YMMV, just my. 02

I already have a Barnes reloading manual on the way in the mail. It will be the 4th reloading manual I have purchased.

[1859sharps]

Same reason why 7.62x54, 7.62x39, 7.62x25 are all 30 cal

I has been a really long time since I looked at reloading for any these, but I seem to remember that these particular 30 cal cartridges were .311 and not .308.

Can anyone who is more experienced confirm?

[emptybottle151]

I has been a really long time since I looked at reloading for any these, but I seem to remember that these particular 30 cal cartridges were .311 and not .308.

Can anyone who is more experienced confirm?

Yes, but still in the 30cal family.

[1859sharps]

Yes, but still in the 30cal family.

sorry, should have been more clear, I was looking at it from a safety issue and maybe a accuracy point of view. I realize they are both technically 30 cal.

[fallfornoone]

The higher pressure is not just from reduced case volume. When volume is the only variable that changed then yes it is
E=MC^2
Energy = Mass * Velocity squared.
A heavier bullet = increased mass.
So you need to reduce velocity so that the total energy output is the same due to the increased mass. Too much energy and you may create a bomb instead of a safe (for the gun and yourself) projectile.

not really correct

Keeping the charge the same and using a long bullet will result in a decrease in volume which will equate to an increase in pressure (of course we are assuming ideal conditions, constant temperature and so on).

The energy of a bullet is given by KE = 0.5MV^2

[Syntax Error]

The higher pressure is not just from reduced case volume.
E=MC^2
Energy = Mass * Velocity squared.
A heavier bullet = increased mass.
So you need to reduce velocity so that the total energy output is the same due to the increased mass. Too much energy and you may create a bomb instead of a safe (for the gun and yourself) projectile.

E=MC^2 isn't even the kinematic equation for calculating kinetic energy. The variable c is the speed of light.

KE=0.5MV^2 is probably what you were thinking of.

[JMP]

E=MC^2 isn't even the kinematic equation for calculating kinetic energy. The variable c is the speed of light.

KE=0.5MV^2 is probably what you were thinking of.

Maybe he's got uranium bullets.

[CSACANNONEER]

I already have a Barnes reloading manual on the way in the mail. It will be the 4th reloading manual I have purchased.

Congrats. It sounds like you're just starting your load data collection. I think I have about 4 boxes of reloading manuals. Even with all that, I called Barnes today and Ty emailed me some .270 win and 50BMG data. The 50 data was just for fun. It's the exact same data that's been published.