Yes. The test data was 5 round averages. the difference is big enough not to be noise.
Lead vs Plated Bullets
- Thread starter Ganderite
- Start date
Yes. The test data was 5 round averages. the difference is big enough not to be noise.
I tested identical loads, one w cast bullet and one w plated bullet and the plated one was faster. Makes me think the extra friction of the plated projectile allows more pressure to build up as the powder is burning which results in more velocity.
I was shooting a lever action so no cylinder gap
Yep, that was not the result I was expecting to see.
what caliber and what was your load?
How large a factor is the coefficient of friction of the bullet in relation to the effort required to accelerate its mass through the bore? In fact it's very small in relation to the energy required to accelerate a bullet from zero to its MV (e.g. 1000 fps) in 3-4 inches. The same applies in a rifle.
Where the "hardness" of a bullet (be it a solid of lead or copper, or a jacketed bullet) significantly affects resistance, is at the moment when the rifling engages with the bullet, i.e. the first 1/2" or so as pressure builds to its peak. Once the bullet is engraved, it's surprising how little resistance it offers as it passes through the bore.
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Rifle was Rossi R96, which has not been cleaned in prob 400 rounds.
38 Special: 158gr commercial cast / lubricated 3.8gr Bullseye = 960 fps
158gr Berry's plated 3.8gr Bullseye = 980 fps
One caveat to the data above is that those velocities came from 3 to 5rd shot strings. I say 3-5 because there were some chronograph errors and I don't remember which loads had the errors and missed a round. Maybe, just maybe, if I did more testing the numbers would reverse but I wouldn't hold my breath on that.
No. Don't care.
I also didn't weigh them to ensure they actually weight 158gr, because ..... I don't care.
We believe or perceive that the bullet, once moving, slides down the bore smoothly. Years ago I read an article that suggested the bullets actually jump forward then slow down before being shoved forward again, multiple times before exiting the bore. I have no idea if this is true but its an interesting assertion
The primer alone can generate 10,000 psi if there is powder in there, taking up room. This can push the bullet into the throat, waiting for the powder to ignite. If it does not, the bullet is stuck in the throat - hopefully blocking the next round from chambering.
If you forgot to put the powder in the case, the empty space takes up the pressure and there is a good chance the bullet will stay stuck in the case.
If you forgot to put the powder in the case, the empty space takes up the pressure and there is a good chance the bullet will stay stuck in the case.
