.500 caliber wildcat idea.

[Andrew Mason]

I have allways had the dream of developing my own wildcat,


I have been thinking recently,
what if I cut the shoulder off of a .300 RUM, or any rum for that matter, and then seat a .500'' diameter bullet,
lots of case capacity for these big, heavy bullets!


my thinking is to have it headspace off the case mouth, so in that case, im not sure how to design the throat for this cartridge.

what are your guys thoughts?

[EDG]

I have headspaced rifle cases - the 7.65 Argentine Mauser off of the case mouth because the Mauser chamber has a square corner at the end. To make sure this had the best chance of working (the shoulders were pushed back too far) I expanded the case mouths to a trumpet shape so there was no question that they would engage the end of the chamber very firmly.
When fired the first time the cases got shorter by about .007 as they expanded.

You idea might work if the chamber and FL die were very close in diameter so there is little expansion.
Otherwise you might have to fire form the cases with a very fast burning powder to stretch the case diameter so it does not shorten when fire formed.

[longbow]

Been done:

http://castboolits.gunloads.com/showthread.php?85616-50-Hushpuppy

Looks like a good idea though and your thoughts might be somewhat different as well.

I could never quite figure out the issue with head spacing off the case mouth as long as there is enough cartridge wall thickness and reasonable fit to chamber.

In fact the .444 rimless headspaces off the case mouth as do a few other wildcats and even some standard rounds like .30 carbine and .450 Bushmaster. So certainly doable.

Have at 'er and post photos!

longbow

[Andrew Mason]

plenty of info on his .50 hush puppy,

but NOTHING on the RUM .50 cartridge, I tried looking for his post, but I was unsuccessful.

[BK7saum]

Search 50 razorback. It is 0.510" bullets in a rum case cut to 2.375". I don't know of a rum case with 0.500" bullets, but someone somewhere has likely done it. I have a 0.510" barrel on my bench and an ultramag 700 action arriving Monday for a 50 razorback build.

Brad

[JFE]

It has been done commercially in several versions up to full length RUM cases. Win M70 CRF actions are used as a means of controlling headspace and there is a 500 version to suit WSSM, WSM and full length M70 actions. Here is a link to their website:

http://m.b-mriflesandcartridges.com

[Andrew Mason]

yea, I found that site the day after I posted this.
pretty cool rifles!!

a full length .500 RUM case! wow!

oh well, so much for my idea to be original.
ill have to keep looking.