I have a Brno 602 action spare and I was going to build a .500 A square on it, however I found a .585 Nyati case

I don't need or want the raw horsepower the full length .585 can generate, but QL shows that a case with about 140-150gns H2O will give 2000 fps with decent case fill using 2207 (H4198) and either 650 or 750gn bullets.

Sooooo how short would I need to run the reamer in to get a case of 140-150gns?

not the same .. the 550 express is about 125gr of h20 and will throw a 700gr bullet at 2200 fps, under 62k psi and fits in a mauser

check bertram to see if you can get brass for the nyati, which is a PITA to build

Thank you. Who makes .550 bullets? Bertram makes the brass I'm sure.

I just want an over .510" planking rifle.

Wasn't really suggesting the 550 .. but its a blast .. the 550 magnum, designed to fit in the cz550, which means it will fit in a 602 just fine, it also a blast ...

cast bullets are fine, with a GC, if you want.

I looked at doing a short t-rex a couple years ago .. did the drawings, etc, and decided to nah, as the boltface was too much of a gamble

Cutting Edge Bullets makes 550 bullets.

I would like to hunt with a 550 Express (Not 550 magnum.)in a single shot.

Sorry to have wandered off topic a bit. Brian

Thanks for the replies guys.

quote:

Originally posted by Aussie steve:
I have a Brno 602 action spare and I was going to build a .500 A square on it, however I found a .585 Nyati case

I don't need or want the raw horsepower the full length .585 can generate, but QL shows that a case with about 140-150gns H2O will give 2000 fps with decent case fill using 2207 (H4198) and either 650 or 750gn bullets.

Sooooo how short would I need to run the reamer in to get a case of 140-150gns?

Hello Aussie steve,

It was back in July of 2015 that I purchased a rifle from xausa (Bill), a fellow forum member here on AR. The rifle was built in the late 1970's by Bill and his partner, a then well know Custom Gunsmith named H.W.Creighton. All of the Creighton installed barrels are marked "CP" which stands for "Creighton Proof". The rifle was chambered in a wildcat caliber developed and named by Bill as the 577 VSRE.

That stood for a .577 bullet used in a Very Short Range Express rifle.

Bill's 577 VSRE cartridge is based on a 577 Nitro Express case that is shortened to 2.500" with its rim rebated to .583" diameter, the same size diameter as a 460 Weatherby Magnum rim. Some 15 years later, upon the development of the 585 Nyati by Ross Seyfried, a variation of that same case, with a 2.787" case length and a .579" diameter rim, could be shortened by approximately 3/10 inches and used for the 577 VSRE cartridge without the laborious reworking of the head of a 577 Nitro Express case. This now means the 577 VSRE, is actually the 585 NYATI SHORT.

585 NYATI SHORT


The whole purpose of Bill's 577 VSRE cartridge was to obtain the same ballistic performance of the 577 Nitro Express Double Rifle, except in a bolt action repeating rifle. That being 2050 fps with a 750g bullet.

This is what I would suggest for your project. The 585 Nyati short already exists, and I have loading data for it.

My 577 VSRE Winchester Mod 70 repeater. It has a McMillan Stock, and weighs 12-1/4 pounds. The Winchester was topped with a 4x24 Noske Scope #528 LER w/ Post in Weaver Rings & Bases. This is one of my favorite Big Game rifles.

As for the 550 caliber, I recently purchased this rifle from an Ohio Auction House. It is 550 Express caliber. It is a slightly shorter version of the 550 Magnum, so it can easily be used in a standard length action. The rifle's descriptions mentioned gabon ebony, reinforced stocks, Breako recoil reducers, Timney Triggers, and NECG sites and fixtures. The rifle was built on a P17 platform. It has a large forward mounted recoil blocks attached to the bottom of the barrel. The block and the rest of the action are totally glass bedded with a grey bedding material. This might also be a caliber for your consideration.

Do you know if that is a Pacnor or Bauska barrel? If Bauska, I may have consulted on it

quote:

Originally posted by jeffeosso:
Do you know if that is a Pacnor or Bauska barrel? If Bauska, I may have consulted on it

Hello jeffeosso

here is all I know

http://forums.accuratereloadin...1019521/m/2191052072