quote:

Originally posted by RIP:
Doc M,
Yep, workable, thanks.
Will play with the 375-grainer next, or just save it for 50 B&M AK.

Jim,
With the 49-10, there is no sweat for case capacity with the longer, boat-tailed W350 ESP Raptor at 2900 fps,
but those flat-based 365-grainers with 10-grain tip added would come in at 375 grains ...
And I have samples of those to try too, thanks to Doc M, bless his heart.
They look brand new too, not even rolled on.

Jim
"Life's hard; it's harder if you're stupid"
John Wayne

quote:

Originally posted by michael458:
As most of you know, Alasken-Oz came down for a visit a few weeks ago, and Brent also was here one day during that visit. Oz has a 50 B&M built on a Ruger Alaskan. Here it is, we have shown it previously.



Now the one thing that intrigued me from the beginning about this rifle is it's 3.4 inch magazine. What this means is that Oz can load any .500 caliber BBW#13 NonCon, add the new Talon Tips, and they work slick as can be in the magazine. Pretty neat! And if I were not such a hard headed bastard over a Winchester M70, I would have myself one of these! But, I am just that hard headed, so this has been bugging me since Oz was here, until this morning I could not contain myself any longer!

My first thoughts were that I could take one of my coveted long action RUM Winchesters, the ones that the 500 MDM are built on, and just build myself a short 50 B&M on that long 3.6 inch magazine action! Easy! I already tried running 50 B&M through a 500 MDM and they feed and function perfectly, retain, the works, zero issues.

Then I started thinking, maybe I can seat the BBW#13 NonCons out further, to that first groove, crimp them in and increase case capacity this way. So I made up some dummy rounds.


Worked through a 500 MDM like butter, slick and easy. OK then I decided, why not make up some live rounds, and go ahead and shoot them in the 500 MDM and see what happens? I suspected the LONG bullet jump from a 2.25 inch 50 B&M to the 2.8 inch 500 MDM chamber might cause an accuracy issue, but let's try and see what happens.

So I did just that this morning. I started with the same exact loads high end for the 500 BBW#13 Solid and the 450 BBW#13 NOnCon, only seated out long like you see above. I new that velocity would have to drop on these because of the added case capacity, along with pressures as well. I used the tips throughout this test as well.

With 70/H-4198 (gives 2250 fps in standard 18 inch 50 B&M) gave me 2200 fps in the 500 MDM. 66/H-4198 gives me 2150 fps in the 18 inch 50 B&Ms, and seated out further gave me 2050 fps in the 500 MDM. Accuracy was very good--I am most likely responsible for the 500 gr SOlid being hi and slightly right here. 3 rds each.



OK--Encouraged by this accuracy which I did not expect, I loaded everything up two grains. Tried again. This time, the 500 Solid increased to 2100, and the 450 NonCon to 2250. Accuracy on the Solid held rather well--but the 450 was not so good, and POI between the solid and NonCon appeared to be more drastic?



OK, so I dropped the solid at this point out of the tests, as I was pretty sure as I increased velocity my accuracy was going to hell. I might have been shearing bands for all I know, with that much added bullet jump, over a 1/2 inch. So I went back, 2 more grains in the 450 to 74/H-4198. This should take it over 2300, and it did to 2307 fps. Accuracy still an issue.



So at this point I gave up on actually using the 500 MDM and shooting 50 B&M ammo through it. I figured that accuracy was going to be an issue, as I have done this before shooting 50 B&M Super Short in the 50 B&M rifles. Accuracy was poor there as well.

So then I got to thinking about that extra magazine length I had in the Win M70 RUM rifles, and decided that a 2.5 inch .500 caliber case would work out really nicely, and be able to use any of the standard NonCons available in .500 caliber, put the Talon Tips in, and it would work through the magazine just dandy. So I made a few dummy rounds up a little while ago, and I think there is going to be yet another .500 caliber cartridge available-- let me introduce you to the;

500 B&M

2.5 Inch RUM Case 450 BBW#13 NonCon with W-Talon Tip Added COL---3.50 Inches, room to spare in the magazine. Matching 500 BBW#13 Solid works, feeds slick as can be.



I figure 19 Inch Barrel here on this one. 450 BBW#13 NonCons at 2400 fps easy, followed with the 500 BBW#13 Solids at 2250-2300 easy. More than enough, and maintain a fairly small package. Will use a smaller contour barrel than comes on the 500 MDM to reduce weight as well. Same barrel contour as the 50 B&M.

I think I will put a reamer in the works Monday!

Just FYI
Ya'll have a good weekend!

Michael

Jim
"Life's hard; it's harder if you're stupid"
John Wayne