Pound Cast, a la Ian

Rockydoc

Rockydoc

Well-Known Member
Here is a photo of a pound cast done in the style of Ian of my Ruger #1 30-30 Winchester.
I haven't figured out how to add text to the photo yet so I will try to describe where the critical measurements are.

The section just above the case mouth is .3331" in diameter and .104" long.
The next section tapers rapidly over a length of 0.045" from .3331" to .3085" .
The rifling starts at full depth from that point at .3085".
The sharp dark lines in the middle of the section just above the case mouth and just above the start of the rifling are what is left of grease grooves on the pure lead bullet pounded into the chamber throat.

How do I use these measurements to order a mould?

What would be the diameter of the nose if I wanted a bore riding bullet?

What would be the diameter of the driving bands on that bore riding bullet?

If I wanted a tapered bullet such as the SAECO # 315, what would be the diametersof the drive bands?


IMG_0266.jpeg
 
Ian

Ian

Notorious member
What a nightmare of a throat! Based on my own trials I'm goint to say ou don't want a bore-riding bullet even though your rifle's throat is essentially two parallel diameters. Reason I say that is the narrow lands won't provide enough support to the front end of the bullet to keep it centered in the bore when the back end is crossing that giant cavern of space. Also, and this is very important, a bore-rider won't seal up the bore as soon or as well as a bullet with a smooth taper or ogival nose will unless the front driving band is tapered. To be successful with this shape of throat you have to use the case neck and the abrupt throat (at groove diameter, not bore diameter!) to support your bullet straight in line with the bore so the bullet is well-supported by the whole diameter of the the barrel as its base traverses that big, open gap between the case mouth and abrupt throat.

Order an Arsenal 311-170 RF mould, lubricate the space above the gas check and the groove above it, size the bullet as large as your chamber neck and case necks will allow and still give at least .001" total loaded neck clearance, and seat for firm engagement of the ogive with that abrupt throat (but not so hard it sticks).
 
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