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Daekar
03-30-2021, 03:32 PM
I have been mulling over a number of different ideas about boolit designs and I was wondering about how you might maximize usable case capacity for a given bullet weight in the context of a single-shot gun - well, you just move the mass outside the case. But there are a few details....
1) Determine the minimum amount of bullet that must be seated in the case to guarantee acceptable hold and coaxiality, then design for that seating depth.
2) Use as much of the throat as is practical, with as much of the bullet at bore diameter as possible.
3) If additional weight is desired, neck down the bullet and extend it into the bore.

In my CAD tinkering, this results in something that looks like of like a SWC with a long nose on it that doesn't taper much. Surely I'm not the first person to think along these lines, so there must be a reason I haven't seen bullets like this around. Does anybody know what goes wrong if you try something like this?

EDIT: See Post #6 for drawing of a boolit designed with these ideas in mind.

gwpercle
03-30-2021, 06:12 PM
Post you drawing ... lets see what you have in mind .
I have always been a mould / cast boolit enthusiast ... don't know why ... but buy , beg , borrow , steal any mould in handgun calibers .
Studied Elmer Keith's writings on his boolit designs ... he was way ahead of his time and have talked to Al "Swede" Nelson of NOE about boolit design . Al Knows a lot about design , what works and what doesn't work , too .
A good many of his NOE mould designs can be downloaded and printed ... not only interesting but they look cool on the wall !
Lets see what you came up with .
Gary

Cosmic_Charlie
03-30-2021, 07:07 PM
I have been seating my boolits out far in my Henry single shot .44. Having the boolit contacting the lands promotes concentricity and improved accuracy greatly.

44MAG#1
03-30-2021, 07:13 PM
My belief is if Accurate Molds doesn't have it listed then it probably isn't needed although I have had him change a measurement or two on his existing designs and he did.

Mk42gunner
03-30-2021, 10:02 PM
Sounds to me like you will run into the same problem cast spire points have-- unsupported nose weight, allowing the nose to slump unevenly; therefore throwing balance and accuracy out the window.

I could be wrong, but you don't see a lot of cast spire point molds anymore and I think this is the reason.

Robert

Daekar
03-31-2021, 07:10 AM
Post you drawing ... lets see what you have in mind .
I have always been a mould / cast boolit enthusiast ... don't know why ... but buy , beg , borrow , steal any mould in handgun calibers .
Studied Elmer Keith's writings on his boolit designs ... he was way ahead of his time and have talked to Al "Swede" Nelson of NOE about boolit design . Al Knows a lot about design , what works and what doesn't work , too .
A good many of his NOE mould designs can be downloaded and printed ... not only interesting but they look cool on the wall !
Lets see what you came up with .
Gary

Here's a drawing of the kind of thing I was imagining in NLG form for a 357 Magnum. The bottom section below the crimp groove is seated in the case, the groove-diameter section above that takes up as much throat space as possible, and the necked-down portion protrudes into the bore. It's possible the groove-diameter area is too long and the necked portion will need to start a bit earlier, but that might depend on the gun.
280586

A render of the boolit:
280587

BTW, credit to the Accurate folks for providing such a comprehensive library of design details as examples, it was much easier to determine "normal" dimensions for things like the crimp groove and amount seated in the case thanks to them.

EDIT: Here's another take on the same kind of thing, this time with a bore-riding section. I did the math on this one, and without the bore segment it should be around 150gr. With the bore segment, it climbs to around 230gr. If it works, you would have a boolit the weight of a long wadcutter but with the available case capacity you'd expect of a boolit 80-100gr lighter.
280596
280597

JonB_in_Glencoe
03-31-2021, 08:35 AM
I have a real old 4 cavity Hensley mold (circa 1930s) that is stamped 38-150. It is a Long nose WC.
It is .358 150gr boolit with a long straight sided nose with a .350 meplat.
Basically it's a WC that is designed to seat long in 38 Spl. This long nose WC is kind of a bore-rider, but better put, a throat rider. I see it as "opposite thinking" of a typical WC, that is designed to take up extra case capacity in the 38 Spl case.