I was just trying to remember if anyone had ever come up with a 50 cal cartridge that fit in a 3.4 magazine box? If anyone knows of one, please chime in and list them here.

Thanks
Joe

the 500 a.r.

https://forums.accuratereloading.com/eve/forums/a/tpc/f/4711043/m/681106016

500 jeffrey, 50 alaskan

Has anyone ever heard of or worked with the 500 Van Horn Express. Its right along the lines of what I have been looking for but it is still a bottle neck round. Idealy I would use the 404 case, cut off at 2.5 and tapered with no shoulder to .510 diameter. Would that require a new follower on a typical 98 Mauser?

I think the 450 Howell simply necked up is what I have been looking for. 2.5 long, .544 case head, tapered to .510 at the case mouth. Should be close to 120 grs of water capacity.

You are on the wrong track thinking a .510 caliber bullet can be used with a .404 Jeffery case head or even a RUM case head unless you are planning to headspace on the case mouth like a .45ACP.

Are you forgetting the neck thickness of brass you need to hold the bullet, and the body taper you need for proper function?

Gil Van Horn, was still alive early this year when I talked to a friend of his. To say he is a bit of a recluse is an understatement.

He did a bunch of stuff way back when.
I am still trying to pin down some dates.

He turned the belts off of .460 Wby cases when he did not have a ready supply of .416 Rigby cases, so the .500 Van Horn Express (2.5") is a few thou smaller at the base than jeffeosso's .500 AR. Here is page 414 from Ken Howell's Designing and Forming Custom Cartridges. You will notice also the mythical .500 Weatherby Magnum using a .512" diameter bullet, which is not the work of Gil Van Horn, IMHO:

Rip,

If I'm reading that drawing right, the rim diameter is .5790. That would require the bolt of a normal 98 or Mark X to be opened up. If the RUM case were used, this would simply be a re-barrel job for any long action Mauser. There would be a loss of capacity over Van Horn's round, but the questions are these: Would it have enough power to be effective given the reduction in case capacity and would it feed without altering the magazine follower?

You are getting the cart ahead of the burro!

First, will it go "BANG" everytime you pull the trigger?

First you have to make sure it is a physical possibility to support a bullet in the neck and a primer in the base, with enough taper and shoulder in between to function reliably, not just sometimes.

Of course it would be powerful enough for any game animal on the planet.

Altering of the box, follower, feed rails and ramp would be needed for sure if you are starting with an action set up for an H&H case head.

The difference in rim diameter between the H&H and the RUM is .002. I'm by no means a machinist but would that be somewhat tough to do accurately on the interior surface of the bolt face? The belt diameter of the H&H compared to the body diameter of the RUM is .020 larger in favor of the RUM. I can see the difficulties of using the larger Rigby case for this round, but would the smaller Jeffery/RUM present much of an obstacle? With a radius difference of just .010 between the belt and body diameter of the two parent cases, the follower would need little if any modifications. I took a friends 375 RUM and compared the follower to Mine, I can see almost no difference. I guess the easiest way to find out is go and create the round.

When I asked about enough power, I was referring to the belief that there needs to be a velocity of 2200-2400 to be effective. I personally don't buy into that but most seem to follow it.

O.K., the follower will probably work as is.

What about all the more important stuff?

Gotta get the burro hitched to the front of the cart.

., Gotta get the donkeys figured out.,. A 416 Rigby shortened to 2.5 " and necked up with a 20 deg. shoulder and a caliber length neck would work just hunky dory ., Or neck up 460 Short A-Square brass., That would probably be the fastest and easiest and undoubtedly the most reliable as it has a good belt to make things work every time ...Or just spend the $ and have AHR build you a 500 AHR or A-Square.. .,

You're right RIP, lets look at case tension and bearing surface. Will this round hold up after being bashed into the front of the magazine box under recoil. The 458 Lott seems to have the respect of most here so lets use that as a basis of comparison. It is a straight walled, tapered case designed to work in all situations. The case tapers from .513 at the base to .480 at the case mouth. That is a difference of .033 over the length of the case. The Rum cut at 2.5 will taper from .550 at the base to .532 at the case mouth. Thats a difference of .018 over the length of the case. So the RUM case tapers .015 less than the H&H case. That would increase the tension on the bullet once seated, but would it be to minimal to facilitate reliable feeding.

The taper on the round in question is .00782 per inch of case.

The 500 Nitro Express is .01433R per inch of case.

The 458 Lott is .01279 taper per inch of case.

The 577 Nitro Express is .019 taper per inch of case.

the 470 Capstick is .00456 taper per inch of case.

So, My new round would be straighter than the old Nitro rounds but less than the Capstick.

Gumboot, There's no doubt that the 460 A-Square short or the 460 Van Horn would be easier. The brass and dies are already out there waiting to be bought. My only intention here was to use the cheap RUM brass with a minimum modification to produce a rifle capable of going anywhere and hunting anything. No matter hunting the Selous of the Tok highlands. I have this thing about spending money and time hunting, not making brass or searching endlessly for components. If I could figure out a way to make a .510 caliber cartridge on the RUM case head, and not have it break the bank to be built or to feed, I would consider this a success.

Joe,
How are you going to set the headspace? Off the case mouth? .510 bullet - .532 neck = .022 /2 is .011 brass thickness. No belt?

No belt was the idea, mainly to save room in the magazine box, however, you make a good point. Head spacing on the case mouth is less positive than a belt and prohibits crimping the bullets if there is a desire to do so.

Any good smith can open up your bolt to Rigby size. 500 AR anyone?

Oh well, so much for a simple barrel job. The 500 AR looks better and better all the time.

Just out of curiosity, is there a belted case in between the .582 Weatherby and the .532 H&H case?

H&H case has a .513 base, and for in between
I just made one for Boomstick, belt .546",
base .532", from 375 Rum brass. Going to
be a .500 diameter bullet. That gives enough taper to extract ok at high pressures.
Look at the long thread on the
wildcat forum. Boom may is working to
get Quality to make slightly larger base/belt version for 510 diameter so as to have a
taper for good extraction.Ed

https://forums.accuratereloading.com/eve/forums/a/tpc/f/6521043/m/972108966

right now if you want to do belted rum brass the .500 is the best but we are working on getting the belted 510 and 505...you can do the 510 if you dont mind paying a premium for brass about $2.25 a a piece minimum 300. the 500 can be done today without the custom brass order.

well if someone wants to do the 510 max and have a custom small run of brass to get the gun up and going to do load development and have fun with it ed will do it but the cases will be about $3 a piece. the brass lasts a long time since there is no shoulder and it is pretty straight. so if you want to do the barrel swap thing on a rum or h+h gun...its doable. the brass will end up costing about the same as regular brass since you will get more firings per case.

How many cases for the initial run?

quote:

Originally posted by Joe Miller:
I was just trying to remember if anyone had ever come up with a 50 cal cartridge that fit in a 3.4 magazine box? If anyone knows of one, please chime in and list them here.

Thanks
Joe

Joe,
I have



the largest case with headspace you can do on a RUM case is .475

Jeffe, I have several actions setting here waiting for something to do. Most 98 Mausers of one sort or another and an Enfield of two. Both Enfield's are Eddystones that have had the barrels removed and then the actions x-rayed for cracks. How would you feel about an Eddystone 1917 taking on this round?

Joe,
I am doing a W enfield for the first one... and I built 2 500s on Eddytone enfields.. no problem. do a search in gunsmithing where i showed some pics of safely removing enfield barrels, that will let you use E's.

they turn out okay!!

Jeffe, is that rifle done in some sort of silver finish or is the metal still in the white?

quote:

Originally posted by Joe Miller:
How many cases for the initial run?

if you are having ed do them it will be however many you want...50 cases would last you a long time and you could do all the load development and have a lot of fun with it and then if desired qual cart will do 300 min order and there will be a headstamped case and he will absorb the tooling costs for future runs to sell to the public. cost per would be about $2.25 or $2.50 each. he is still figuring out how much labor it would cost so that is a ough estimate.

one of the philosophies of this gun is to get 500 nitro express power on a barrel swap and still get 3 down with minimal smithing and costs required. the custom brass is outsidethe total costs goals but like i said the amount of firings per case in increased through the design of the case.

this is like the 470 lott scaled up to 500...

welcome back el jeffe!

Joe,
it's a WIP.. sorry, i had mentioned it before here, but it's not the biggest thing in the world..

i'll bump the 500AR thread

i had my wisdom teeth out, and can't shoot, so I haven't been doing ALOT..

Boomy,
thanks!!

Joe, it generally takes 5000 pieces to do a custom run of brass

As I recall, Jack Belk made a interesting wildcat by shortening a 416 Rigby case, blowing out the shoulder (perhaps) and necking it up to a 50 cal. or so it seems.

quote:

Originally posted by Atkinson:
As I recall, Jack Belk made a interesting wildcat by shortening a 416 Rigby case, blowing out the shoulder (perhaps) and necking it up to a 50 cal. or so it seems.

buhmiller was the first it seems to do this on a full size but to see how much belk shortened it would be interesting. can you find out or get ahold of him???

i emailed him from his site and am waiting for a reply.

Ray,
iirc, Jack mentioned the vanhorn,, he DID shorten the 416 to 2.5 and it stayed a 416, and i tried to buy the reamer, but he couldn't find it. he did a 7 and a 416 2.5" rigby. He didn't do the 510