Mountain Molds

from the old forum:

I was asked about a Ross-style 510 gr. GC bullet for the 500 S&W.

John Ross really likes the long nose design because it frees up more powder space. It makes sense for the very heavy bullets. However, the 510 gr. version as shown below has very little full diameter bearing length and carries little lube. Some people have good luck with them, but I have to ask, what is the point, since the big case has gobs of powder capacity?


If it were me, I'd think about shortening the nose to give 100% loading density with H110/WW296. That would increase the bearing length, lube capacity, and give up almost no velocity. Here's one example:


As for load data, I have had good luck using Quickload for wheelgun cartridges and H110/WW296, and of course, using a chronograph for a sanity check.

Here some examples of QL predictions for H110 at 50 ksi:

Ross design with 0.700" long nose: 44.5 gr., 1594 fps, 87% load density

0.500" long nose shown above: 39.0 gr, 1534 fps, 93% load density

I guess it depends on how badly you want that extra 50 fps;

As you know I have many of your SW 500 and 475 moulds and I prefer 2 lube grooves ,3 would be even better especially at the pressure generated by the SW 500 and 475 Linebaugh and 475 Maximums.Leading begins when I have 2 small grooves or less.

I have a 495gr mould noselength .389,and I have a 515gr mould noselength .550,max velocity is for all practical purposes the same 1540 fps,so the noselength did not increase max velocity even though powder capacity was increased.

Sean

There are several 50 caliber Whispers tossing slugs up to 750 grains suppressed and they work well. We have a 45-70 and have shot up to near 600 grains suppressed but the 520-550 range were more accurate and quite impressive.


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