I am having some 475 cal. banded solids made and I am wondering what the "best" diamiator for the meplat is recommended by the group? I am looking at one about .340 wide and the weight to be 450 grains.
Thoughts?

I am also working to have Barnes 425 TS made up. The meplat on those should be about .300 so they will work with put problems in a lever gun.

75% of caliber is "huge" .. should have a slight radius (r.0625) on the front corner, shoulder, think keith bullet style, should be .005 smaller than main diameter, should have the LEAST and CONSISTANT bearing surfaces possible.

length should be the thing to watch. 1.2" long, max

if you have 425gr TSX made up, this is easily possible by "deducting" the long shank on the rear.. if the groove and band were the same, all the way down, and ENDED you wind up with about 400 gr... which works great

jeffe

Doug,

I am doing a run of .475" x 475 Grain banded solids for the "Ususal Suspects" here on the big bore forum this week. You are welcome to join them. I will be shipping them out on friday.

I would like to but, the length of the bullet from the crimp groove to the nose/meplat needs to be about .500+- and the meplat to be +- .350 to feed in the Win 86. The total weight will end up about 420 grains.
Doug

quote:

Originally posted by Doug Turnbull:
I would like to but, the length of the bullet from the crimp groove to the nose/meplat needs to be about .500+- and the meplat to be +- .350 to feed in the Win 86. The total weight will end up about 420 grains.
Doug

Doug,
It sounds like you have it figured out.

The ultimate FN solid design is that of GSC in monometal copper.

The .475/500-grain FN by GSC has a meplat that is about .400" if left square on the corners. It is not, however, as it has a radius of about .050" on the corners of the nose. After this rounding of the sharp edge for feeding purposes, the remaining flat on the nose of the bullet is only .300" in diameter, by my eyeball-and-caliper.

The truncated cone of this GSC FN is about 5.5 degrees angle at each side, or about 11-degree cone angle with the tip cut off to make the FN.
The nose portion ahead of the first band is about .680" long, about .700" if crimped behind the first tiny band. The overall bullet length is about 1.395".

Using your design parameters, you will have to use a greater cone angle to do it with such a short nose, and short overall bullet length.

You will need to put a .025" radius on the edge of that .350" meplat of your bullet. That will leave a .300" diameter flat remaining on the nose of the bullet.

That should work fine.

Doug,
Please have a driving band centered on .820 from the nose, and this will allow "everyone" to be able to crimp and set at "normal" length for other rounds

thanks
jeffe

Jeffe,
Good thought.
If that .475 Turnbull bullet is a multi-cannelured/grooved bullet like a Barnes or a banded bullet like the GSC, it will certainly be useable in many other .475-caliber rifles.

Not sure how this observation relates to rifle solids, but in the big bore revolvers 475 and up a meplat of 78% flat point has shown to out penetrate smaller meplats...All hardcast flat points....

i might not have been clear...
there needs to be a GROOVE .040 wide, centered on -0.820 from the nose, which allows this to be used in the 470mbogo, 470 capstick, and 470 AR
jeffe

Right Jeffe, clear as mud first time around. Groove (or band-interspace) location for perfect crimping in those other cartridges: Ahem!

The shorter bullet would be especially helpful in the 470 Capstick with its limited case capacity.

That means the center of a groove should be (3.6" -2.85") = 0.75" from the nose flat, not 0.820".

Same location as 375 HH & 375 Ruger.

Ooooops!! Same location as the .475" banded solids we're doing this week. WHAT! a coincidence.........

Universal snout size geometry I'd say!

quote:

Originally posted by Macifej:

Universal snout size geometry I'd say!

Nope..
.416, .458, and .510 are generally .820 back... hornady moved the .416 shorter and screwed it up for alot of 416s.

Think about it..
2.85" long case + .800= 3.65, the standard length of HH cases... so, a grove, on -.820 is perfect ... 375HH, 416 rem, 458 lott, 470 capstick, and 500 jeffe .. and, of course, 416, 458, 470, and 500 AR

jeffe

Going to the original question, the perfect .475" solid already exists. Go to www.gscustom.co.za and your quest will be at an end.