What effect would deep seating a bullet have on speed? Seems like its a lot further from rifling than a standard bullet so it would get up to speed better before hitting rifling I tried a few round of cast flat nose round point in the sks, need to chrony it when the weather improves.
Seating deep
- Thread starter bandit86
- Start date
The Weatherby freebore exists because of that theory.
The problem with seating deep is it would increase chamber pressure because you decreased the case capacity. As stated above the longer throat on Weatherby rifles allowed them to attain higher velocities, "BUT" the longer throats on the Weatherby did nothing for accuracy because of the longer bullet jump.
Seating deep and giving the bullet a running start at the rifling isn't going to make it faster, but seating long and adding powder will make the bullet faster. "BUT" it is a balancing act between seating depth, the distance to the throat and throat length as you can read below.
Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) – Part 1
http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-1/
Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) – Part 2
http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-2/
As an example the .223 and 5.56 NATO are loaded to the same exact same chamber pressure of 55,000 psi but the throats are different between the two cartridges.
And to add more confusion the throat on my Savage .223 with a 1 in 9 twist is longer than both my AR15 rifles. The shorter throat you see above is found in rifles with 1 in 12 or 1 in 14 twist rifles for lighter bullets.
Seating deep and giving the bullet a running start at the rifling isn't going to make it faster, but seating long and adding powder will make the bullet faster. "BUT" it is a balancing act between seating depth, the distance to the throat and throat length as you can read below.
Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) – Part 1
http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-1/
Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) – Part 2
http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-2/
As an example the .223 and 5.56 NATO are loaded to the same exact same chamber pressure of 55,000 psi but the throats are different between the two cartridges.
And to add more confusion the throat on my Savage .223 with a 1 in 9 twist is longer than both my AR15 rifles. The shorter throat you see above is found in rifles with 1 in 12 or 1 in 14 twist rifles for lighter bullets.
No, the Weatherby freebore exists to reduce pressure for a given powder charge in a round. The longer the freebore the lower the pressure will spike at, same idea as the 5.56mm NATO chamber.
The problem with seating deep is it would increase chamber pressure because you decreased the case capacity. As stated above the longer throat on Weatherby rifles allowed them to attain higher velocities, "BUT" the longer throats on the Weatherby did nothing for accuracy because of the longer bullet jump.
Seating deep and giving the bullet a running start at the rifling isn't going to make it faster, but seating long and adding powder will make the bullet faster. "BUT" it is a balancing act between seating depth, the distance to the throat and throat length as you can read below.
Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) – Part 1
http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-1/
Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) – Part 2
http://www.bergerbullets.com/effects-of-cartridge-over-all-length-coal-and-cartridge-base-to-ogive-cbto-part-2/
As an example the .223 and 5.56 NATO are loaded to the same exact same chamber pressure of 55,000 psi but the throats are different between the two cartridges.
And to add more confusion the throat on my Savage .223 with a 1 in 9 twist is longer than both my AR15 rifles. The shorter throat you see above is found in rifles with 1 in 12 or 1 in 14 twist rifles for lighter bullets.
Seating deep may actually increase the velocity slightly, because the case volume is smaller therefore the pressures higher and the velocity would increase, though this difference would be minute in practice and, for most shooters, would be completely drowned out by the other variables that affect muzzle velocity extreme spread.
But you're right that seating long and adding more powder would also increase the velocity, this time in a more effective way because you are increasing the amount of gas produce by the powder, therefore the energy the bullet is accelerated with.
