WW Alloy vs Pure Lead - affect on Bullet velocity - same weight bullet & Powder ?

[DoctorBill]

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I am fireforming some reworked 50-110 -> .43 Spanish Cases.

A thought came to my mind (REALLY !) that maybe a pure lead Cast Boolit
might cause less chamber pressure in the rifle
versus the same boolit cast from WW Alloy.

i.e. - Due to it deforming much more easily with lead than WW.....and getting
started down the barrel faster & easier.

Any thoughts based on experimental data - no opinions (Please) ? Data found in
literature ?

I would PRESUME, however, that given the speed of the powder burning and the
Inertia of the Boolits being nearly identical, that the pressure peak would be the same
for both metal compositions. Velocity (fps) might vary, but would PEAK chamber pressure ?

But then, who am I to know squat about that ? I don't want any 'facts' to get in the way.....

DoctorBill

PS - Found THIS online after Googling:
https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/ubb/printthread/Board/34/main/601624/type/thread
Surprising answers ! Never "ASSume" !

[Soundguy]

Keep in mind that if you want to maintain the same weight, that the ww bullet will be larger.
Do you have the ability to make hb bullets?
Do you paper patch?

[charlie b]

If anyone knows it will be Gibson. I know he did some tests between jacketed and cast. IIRC, results were not consistent, ie, some jacketed had higher pressures and some had less.

[DoctorBill]

Yes I Paper Patch. I make Bullet Molds for PP'ing from Aluminum Blocks.
Here I used an 11mm Round Nose Milling Bit. I hone it with 'Flitz" polish until the bullet falls
or can be pushed out. I cast a Bullet with a nail or such in the back end and use THAT with polish
to hone the sides smooth. Works nice. Takes a lot of patience, however.
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The bullets are straight sided 296 gr RN for Paper Patching.

I have made a "D - bit" from Drill Rod Steel, but THAT is a lot of work....
If I make another for this, I will make it the "Postel" shape.

No, I don't have a Hollow Based mold - except for LEE's Mini Ball Mold.

I've made Aluminum PP Cast Molds for my Martini Henry and for my 45-70's.

Paper Patching (Paper Sabot) allows you to shoot any Metal down the barrel
that you want. If you could mold Carborundum you could shoot THAT !

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For the above Cast RN Bullet, I use four wraps of 10 lb Tissue Paper to achieve
.439". Don't have any .002" paper ! I collect paper whenever I find the right kind....

DoctorBill