.505 Burns Ballistics!! What A SLAMMER!!

[MAD DOG]

It is not just every day that a new cartridge comes along and really knocks my socks off. The .505 Burns is one such.
I am working on a rifle in that caliber now, based on a 602 Brno action. I plan to take it to Africa next year.
I have several loaded rounds of this sitting on my desk as I type this. They are truly awe inspiring. They totally dwarf a 30-06 round. They would look very at home in a cigar case. Bwahahahaha!
Dane Burns, the cartridge's father, sent this email to me today, it details the latest load developments. I thought that you might find the dope on this Buffalo stomper entertaining.
Enjoy!
Mad Dog
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Hey Guys,

You know paper ballistics are one thing, seeing the effects of it are another. Enjoy the rest of this

Most of you have known I am working on a new .505 based on the .416 Rigby case.

Days ago I finally chrono'ed the first of a group of semi production rifles Mike Kisler and I have been working on.

While I have load data from a 525 gr lead bullet @ 1850FPS all the way up to a 600gr Woodliegh @ 2500fps, those are the extremes.

I designed the round to be the most efficient big bore available. The loads I wanted were a 525gr. @ 2300fps and a 600gr @ 2200fps. I am close. Just over 6500 ft# of energy on either load as tested. I wanted to better the
.500 Jefferies and the .500 Nitro and keep pressure down. Easy enough to do and with less recoil, if the .505 Gibbs is any comparison for either.

Info from a Pact chrono and A2 data:

From a 21.5" PacNor barrel and a 525gr Woodliegh soft I am getting an average of 2362fps with 100grs of H4895. Pressure is right @ 44K CUP.
SD is 6.7,
CV .37%
MAD 8.8,
ES 25fps....in 20 rounds!!

From 96 grains of H4895 and a 600 grain Woodliegh soft...............2210fps average
Pressure is right @ 39K CUP!!!!!!
SD is 9.8
CV .53% MAD 9.8
ES 23fps......in 20 rounds!

Recoil is less than a similar weight rifle chambered in .416 Rigby with 400 grain bullets at 2500FPS when compared to the .505 with 525 grains @ 2350fps.

All that from a 21.5" barrel. Can't wait to se what a 24" will be doing.
Regards,
Dane

 

[Alaska Roy]

Question?

I was wondering what the ambient temperature was and how Dane dertermined actual pressures with a chronograph? What price range are we talking here for the rebarreled CZ/Bruno? The cartridge certainly looks impressive! Roy

 

[BigG]

Hey Mad Dog,

can you get a 460 Weatherby conversion kit for plinking?? Sounds like a honey of a rifle. I'm jealous!

 

[BigG]

I was just reading in...

Cartridges of the World about African cartridges. The author noted the manufacturers of the "big boys" purposely loaded them to lower pressures as the hot tropical climate, as opposed to more moderate climates like Europe, could cause pressures to mount rapidly.

Never heard of Weatherby worrying about excessive pressures, though. Old Roy had his proprietary cartridges stoked by Norma, not exactly known for wussy loads.