Cast vs copper psi

[charger 1]

I'm going to go out on a limb here and say that I think the pressure required to drive a properly lubed cast bullet at the same speed,same gun,etc etc would be less than the identical weight and speed in copper clad. Would this be the general exeptance....Without all the variable deviations yada yada. I'm just asking if that would be a generally excepted principal

[Bass Ackward]

I'm going to go out on a limb here and say that I think the pressure required to drive a properly lubed cast bullet at the same speed,same gun,etc etc would be less than the identical weight and speed in copper clad.


Charger,

Brahuhuh! Brahuhuh!

Sorry. Give me a minute. My chain saw won't start.

[arkypete]

Charger
I used this theory when I first started loading for my 375 Whelen, except I added one other aspect. Loading data for the 375 was rare to nonexistant when I got my rifle. I had the rifle made specifically for cast bullets, to tinker around with.
OK
I went to loading manuals got loading data for the 35 Whelen, recently reintroduced, using jacketed bullets. I used the same data, powder charges, for jacketed bullets, substituting cast bullets of equal or slightly less weight.
My SWAG, Scientific Wild Ass Guess, was the larger the bore with lead alloy bullets would generate less pressure.
It worked out nicely.
Jim

[Char-Gar]

Humm... I asked that same question on the old Shooters.com about 99. It is going to be interesting to watch this thread and see how things shake out seven years later. I probably learned more from my 99 question, than any other post I have ever tacked on this board.

Let's just say, I started with the same assumption, but the answer is not very simple. The "yada, yada, yada" was what made the thread so interesting.

[charger 1]

Charger,

Brahuhuh! Brahuhuh!

Sorry. Give me a minute. My chain saw won't start.

Not sure I get it. Do I wanta get it????

[44man]

Very true, You can generally use more powder with cast. Lead can expand and contract easier in the bore plus it has some lubricity for less friction. Then the lube also helps.
There are exceptions so you should still be careful and work up. For instance in my .475, one lead boolit shows a lot more pressure then the same weight jacketed with the same load.
Proper loading procedures should always be followed.

[snowman]

Dont forget that your powder charge has to develop pressure to swage the copper clad bullet into the rifling.