I give up!!

[Kurt]

No I wont give up my slow ROT .44's they shoot quite well with the original bullet profiles.

[Frank Savage]

Seems to me that the Money nose shape is somewhat strange. Overtempted by continuously reading about how good to superior a bullet it is, I tried three aproximates of this shape in my current Kropatschek project-and very similar results, albeit it has about 10" twist for 32 cal-have to measure it accurately. But accuracy is proven from this barrel for 247 grs or 1 1/4" long bullets, mine versions were around 1 3/16" @ 237 grs, so should have been OK. But-no consistent accuracy, even 2x2 ft @ 60 yds namely when the PP has contact with the rifling-the more, the worse. Most of the holes oval, or with a "shade", with no concistency regarding the shade position. Made two other nosepunches for mold last weekend, still have to try them-no luck with trigger time during the week. Seems to me that the velocity may be too slow for this nose profile and in my case probably too soft alloy-tested it 1:30 max yet. But even with soft alloy, these patterns must have other reason. And round nose bullets were definitely better.
My guestimation is that for some dia-(ROT)-velocity combos it has too slim nose and meplat/endball, so the point of max. pressure is not as much on the tip of the bullet, but somewhere on the nose, which in combination with diameter too small and too slow rpm may result in inconsistent laminar-to-turbulent flow transfer, which moves up and down on the nose disballancing the bullet. Any slightest imperfection of shape consistency has then an exponential value.
Man, these heavy bullet 44 and 45-hell, almost all BP cartridges in general, are just around the edge of validity of known formulas. Too low Reynolds, too much mass, too long. Much like my folding motorboat-5,2 meter long, 0,8 m wide, 0,14 m draft. No problem to make 8 knots with 70% revs meaning about 3,1 HP of almost museal engine. If you take usual formulas, no way it can go this fast with such limp powaplant. But the classic formulas are OK from draft 30 cm (1 ft) and more...

[Dave Roelle]

Hi Frank:

While not the student of bullet design like Kurt or Don i do find that the faster i push the "Money Bullet" the better it performs ------------(this is a grease groove BACO mold)-----------certainly the Money Bullet as a Paper Patched slug would have different flight characteristics.---------i cast the Money Bullet at about 11 Brinell---results to 800 Yards are as good as i can see and hold.

Dave

Dave

[Don McDowell]

There is one thing that cannot be overlooked on the money bullet, when you get it to shooting well it shoots extremely well, and the match results are there to prove it..

[knobsmt]

Kurt maybe should re barrel to a 38-55 they shoot great in MT

mark m

[Frank Savage]

Yes, I see I was not all that clear-seems to me that Money and similar nose shapes realy needs the speed higher to get somehow controlable flow. Still I have no real world based personal opinion and experience with Brent´s prolates-just a feeling that they may perform better with slow velocities, due to better graduation of the nose shape. (a math stuff here-if you make a derivation of the curve of the Money, you´ll see a hump there for sure, which is not present in prolate. BTW, anyone have coordinates of Money nose for performing this on real data?). And PP slug of Money shape will need even more speed than GG design to get well-defined point of laminar tear-off and consistant turbulent flow establishing, since beside the GG it has no delaminators.

I´m no way a bullet design researcher, less than a mathematician, but spent some years as an avid aero modeler, with some focus on "WTH it flies/does not fly a heck". At one period I was able to mathematically guestimate a polar of a model along with aprox of flight&manoeuvre envelope in less than 5 hrs with pencil, triangle and compass, with no significant differences from reality. No calculator. No way to perform it now, but sth rest in me and pokes me to use it

[Dave Roelle]

Hi Frank-------------the flow dynamics insights left my engineering mind years ago---Theoretical and Applied Mechanics was much more fun but that too had sadly been replaced with managerial duties--------------still got your sliderule

Dave

[Don McDowell]

Kurt maybe should re barrel to a 38-55 they shoot great in MT

mark m

Most especially if you're a blonde haired teenage girl.

[rdnck]

That lets Kurt out...

[Kurt]

There is one thing that cannot be overlooked on the money bullet, when you get it to shooting well it shoots extremely well, and the match results are there to prove it..

Yes they do Don, but you have to remember they are shot from a .45 with a 1/18 or faster ROT. and some of the higher scores are shot with a 1/16 ROT from what I read on the list.
Below are the two bullets I wrote about. #2 is the .44 Brooks Postell, #3 is the .44 PJ MB. you can see the difference in the nose profile.
#4 is the BA .45 MB and it shoots pretty good in the .45-90 but not as good as the #5 BA MB that has a longer shank before the ogive starts than #4 has.
#1 is a .44 elliptical cast with a KAL mould and it is deadly to the .500 mtr line but it starts shooting erratically in the 1/19 twist around the 700 yard line. It has a shank longer than the nose. This is the bullet I use in the .44-100 st. with a 1/17 ROT and I have no rifle that will out shoot it at the 1K.

Mark I might get a .38 when I get old