It's not that I can't build the bullet here, it's just that the software could be a bit more forthcoming. I've been doing or managing software projects for the last 25 years or thereabouts and I am perhaps a little sensitive to these things. I only spent a couple of hours measuring my chamber cast and modifying my design in your system and obviously not all of that time was wasted. But let's say just your text in the "Recommendations" section were in Red
instead of Blue
. Just that small change would have caused me to make a more serious examination of it's contents and perhaps read more on the Forum before going farther along in the design tool. Sometime it's just the little things like that which can make a difference for the user of a piece of software. Even a wording change such as "too long, unsupported ogive" would have given me pause. My mind would have immediately associated that "too long" with "too long to make".
In any case ...
My bullet was to be for the less than ubiquitous .450 Alaskan which chambers in my Winchester 71. I've yet to find a mold for a bullet that takes full advantage of this cartridge. I figure it's time to stop looking and just have it built. My typical hunting load uses the Swift A-frame .458 FN in the 400 grain incarnation. This runs about 2150 fps from my gun and it's to what my express sights are regulated. I also have a substantially less expensive plinking load using the Speer #2478, their 350 grain JFP. At about $0.50 the Speer is 1/3 the cost of the Swift A-frame. I've also tried the .458-400 NorthFork. It's a bit long for it's weight obviously. And it's a tiny bit more pointy than I like.
As you're probably aware, most commercial bullets in .45 caliber for rifles are shaped for use in the 45-70 or the 458 Win. Mag. Those for the 45-70 take up far too much powder space in the Alaskan when seated appropriately for crimping. To get that back I'd have to go lighter than I'd like. The bullets for the Win Mag are extra heavy or extra pointy. Since this is a tube fed lever action, I'm staying away from the "pointy" end of the spectrum.
Measuring the Swift A-frame, the nose length is 0.700", followed by a 0.045" crimp groove, ending in a 0.400" rear section for an OAL of 1.145". The FP on this bullet comes to 0.250" by my caliper. The FP is an exceedingly short section of exposed soft lead perhaps 0.025" in height. This is about the optimal bullet that I've found for the Alaskan. The relatively narrow FP allows me to run an OAL that feeds well in my rifle (but would not in a Marlin so chambered) and also takes up less powder space in the case. The neck section on a .450 Alaskan is a relatively short 0.350" when the case is trimmed to the common 2.145" length. For reference ...
My fired case capacity measures 92.5 grains of water. I believe the fellow that generated the graphic calculated it at 88.1 grains for the drawing. For those shooting the Alaskan in an un-tweaked Marlin, the relatively short nosed 45-70 type of bullets (Hornady #4503) are ideal as the max OAL in the Marlin is about 2.55". In the 1886/71 there's quite a bit more breathing room.
The bullet I had done on your site was as follows ... 400 grain, .459", 0.070" front band, 65% meplat, 91/3/6 alloy, secant ogive, no crimp groove. I used the 0.425" step shank, 0.120" shank length, 0.9 groove-to-band, and the 55 degree groove angle. I selected the 2 band / 2 groove design. This left all three bands approximately 0.070" and an OAL of 1.089". A bit over 1.1" with the gas check seated I figure.
I debated about going .460" in this alloy. I figured the mold would then do the lower alloys at least .459". But since your specs are -0.000/+0.002" I left it at .459".
I know the 65% meplat is bigger than what's on the Swift's FP which is about 55%. I would likely have to load a little shorter than what I load the Swift. But it's not meant to be the same bullet, just something in the ballpark that will hit hard at 50 yards. This is just a starting point. In my estimation, I'm probably 4 or 5 molds away from what works well in my gun ... but you have to start somewhere.
The reason I've been thinking about a mold like this is really to have a backup to the jacketed stuff as well as something more economical to shoot. I've seen too many jacketed bullets vanish from the catalogs these days. The latest being the Nosler .458 300 grain Partition. Since my cartridge suffers from limited availability / appropriateness already, I feel a custom mold is something I should have on hand.
In any case, I do appreciate you taking the time to respond. In case you're wondering, I came here after reading Craig's (6pt-sika) post over on the lever guns forum. He's what I would consider pretty experienced in casting for large caliber lever actions. Marlin mostly but we forgive him for that.