Here's my advice, for what it's worth

i have a 500 jeffery (jeffe) that weighs 10.5... i have been shooting, of late, till it broke the SECOND stock, 535 woodleighs at 2350...

the recoil is AMAZING for the first 100 shots... then you start to get used to it... shoot 5, 10, 10, 10, 15 or so an outting (that's 5 once, then another time 10)

mine is accurate as hell, and I've yet to see a big bore, in good shape, that wont

so, the advice part

have the stock built for you.. LOP and CAST

make sure it weighs AT LEAST 11#

weight should be slightly forward of the front screw

mercury tubes are an option

pachmyer f990 pad

and HOLD ON

jeffe

The 510 Wells is the Gibbs necked up .005", right?
Jeffe, you've said if you did it again, you'd go A-Square. Can you tell me about some of the troubles you had with the Jeffery?

.510 Wells is a 460 Weatherby necked up. It has slightly less capacity than the 500 A-Square, due to taper and shoulder, a miniscule difference.



Here is the chronological lineage of the 50's based on the 460 Weatherby, John Buhmiller was first, in the 1950's:



50 Buhmiller (.510" caliber bullets)

.505 Barnes Supreme (.505" caliber)

.510 Wells (.510")

500 A-Square and .495 A-Square (both .510", the .495 shorter and straight with no shoulder, like an overgrown .458 Lott)

.510 JAB (.510)

50 Peacekeeper (.510)

First,
the brass is about 1/4 the price, and of higher quality than 1/2 of yoru choices

second the jeffery is a rebatted rim, and requires lots of thinking/planning/working to get to feed RIGHT

third, other than the cool name, they can be loaded just about the same (this is not 100% accurate, but close enough)

forth, ANY .510 is cool!!
jeffe

hi Nate; i done some work on a 510 for Daan Pedersen acouple yrs. ago and useing the 570gr. barnes it was a peach to handle,at the time one of my sons was 13 yrs. old weight in at 110 lbs, but he gave it a go,it was three steps back every shot but not painful,the gun was bedded in a mcmilan,2 reducers in the butt,an intergral break that had 2 ports one on each side of the front sight,muzzle rise was slight considering the size of the cannon,i have some video of it but he won't let me put it on the web,he is pretty shy and one shot back him out of the camras field of view,I may never get to the land of the giants to hunt but i would want one if i did,i only took four or five shots my self and found it very nice compaired to some of the rigbys and other big bores. i realy dont recall but i think it was about a 110 grain load of powder and i think that would do anything that roams the earth,a while back some fellow from MO. was on her useing the name 510wells,he gave me a call and said he had fell in love with his, he had taken 3 or 4 trees numerus 5 gal. bucketts of water,and a couple of toyota engines and had fired it about 100 times,so the 510 can be enjoyed.

Ok, so what's the name of the cartridge I'm thinking of, the 505 necked up?

505/510 gibbs...

the 510 wells and 500 asquare are weatherby based.. so is the shorter 495 aasquare

the gibbs is HUGE

jeffe

The Brits might use Jeffe's terminology.

Most Yanks would say ".510/.505 Gibbs" using our convention for naming wildcats.

Some have mistakenly chambered .510 barrels with a .505 Gibbs reamer, like Phil Shoemaker's gunsmith. Then a .510 throat and neck reamer should be applied as a follow-on, for .510 caliber bullets in .505 Gibbs brass.

The .408 Chey Tac necked up to .510 would be a little shorter in overall length, but great brass (thicker web for higher pressures than the .505 Gibbs), and probably easier to come by than the excellent Horneber .505 Gibbs brass.

That would be a ".510/.408 Chey Tac" by Yank convention.

500 Grains,

Thanks for your thoughts.

What materials do you recommend for testing bullets ?

That is, in the absence of 100 buffalos per cartridge/bullet combination....

Hammer

Hammer,



Spaced pine boards (or plywood with board costs these days) and contained sand have been used with more predictable results. For rifles, ballistic gelatin is not really practical since it takes such a huge amount of it.



One of our fellow forumites did some fairly extensive penetration testing using boards and sand and posted the results at www.470mbogo.com.



A modification to that test, which may not be as repeatable, is sometimes used in Africa. They shoot through an elephant shoulder and then into a series of spaced boards. If you had access to a slaughterhouse, you could probably get enough similar beef shoulders to have a reasonably repeatable test.



Robgunbuilder who posts here shoots oak logs lengthwise to test penetration. If you have access to some fairly large and fairly consistent logs, that is another alternative, althuogh not as scientific as the pine boards or contained sand tests.



An interesting article on the subject is here:



http://www.mindspring.com/~ulfhere1/methods.html



Norbert's interesting article on the topic of penetration of solids is found here:



http://home.t-online.de/home/nhansen/penetrat.htm



An African's view of penetration is here:



http://gunlinks.zibycom.com/members/002245268/Site2/articlesta.html

One poor lad bought a rifle in this cal. on the Zim Proficiency test three years back. It certainly put buff down with stunning aplomb :- problem was the lad got wallet flinch as we kept asking him to shoot sundry other animals so we could watch the effect! Don't know what ammo costs but he had tears in his eyes everytime we made him shoot a baboon or impala!

After the speed shoot though he also had a cracked stock and had rattled a filling or two loose. Great caliber if you can afford it, and can use it. ie NOT ME!!!!!!!

RIP, my fading memory recalls a .50 Buhmiller cartridge based on a blown-out and necked up .375 H & H case, with a .510" bullet that had a turned-down heel to fit in the neck. Is there more than one .50 Buhmiller, or am I just plain mistaken?