I don't know why, but this question has been bothering me. I don't really have any plans on building one, I would just like to know.

Master Blaster Mitch Carter's 577 Tyrannosaur had a 1:12" twist (Pac-Nor barrel) and was superbly accurate with all bullet weights.
The 585 Nyati will throw the same bullets at similar velocities.
It should not have a slower twist than 1:12" if you want best penetration.

Ross Seyfried said about his first 585 Nyati:

"The now defunct Matco company made me a .577 x .585-inch, one-turn-in-20-inch-twist barrel ... My rifle began as a purely "workhorse" experiment so the barrel was left the full 1.4-inch diameter, 27 inches long."

Ross refined the barrels on the rifles as he went along. Eventually he got down to a slim 0.800" muzzle diameter.

I think he left some neck dimension problems between brass and chamber for others to refine. Rob can tell you about those.

well, if you want a button rifle, with bauska being out of business, and no one but pacnor cutting them, your choice is 1:18 .. or nothing as buttons are specific to twist
http://www.pac-nor.com/barrels/

I guess you could order a cut rifle at whatever twist you wanted - be prepared to wait a year.

You could even order the button at a faster twist, which would take about an additional 4-6 months

basically, pacnor is the source for it, and your choice is 1:18 or cut rifle

My Nyati has a 1:18 Pac-Nor on it.!-Rob

jeffe,

you need to get out more. My 577BME has a Krieger barrel. They have them in stock, or you can order the twist (within reason) you want and a less than ninety day delivery quote in most cases.

Rich
Buff Killer

On the home page for Krieger they advertise up to four bore. On there barrel caliber chart they stop in the mid calibers, do they offer a barrel, caliber, twist chart for the bigger stuff or is this something that requires a phone call?
Rodney.

on my 577 Tyrannosaur is a 1-12" Krieger Barrel. About 6-8 months waiting time at that time (2006). Works perfect..

Buffalo, does the rifle have any felt torque? Or should I ask does the rifle twist a little while the bullet is moving through the barrel?
Rodney.

quote:

Originally posted by Rodney H.{500Jeffery}:
Buffalo, does the rifle have any felt torque? Or should I ask does the rifle twist a little while the bullet is moving through the barrel?
Rodney.

Smart guy, that buffalo, used a 1:12" twist.

I can answer the torque question from shooting Mitch's 577 Trex: Yes.

Right hand twist (look down the bore from the breech, the rifling will be turning to the right, the bullet will be turning clockwise as it goes downrange):

The rifle will torque to the right.
A .577 Trex requires a thumb over the top of the barrel when shot from the bench, to keep it from jumping off the front rest and laying over onto its right side.

Offhand shooting is easier to control than from the bags.

The heavier and faster the bullet, the more torque.

A slower twist would make for less torque, but what are we, one of Saeed's Champions who cannot hold onto a torquing 577 Trex with a 1:12" twist?

The best thing anyone can do with a .585 NYATI is turn it into a .600OK! A wise man speaketh!-Rob

quote:

Originally posted by Rodney H.{500Jeffery}:
Buffalo, does the rifle have any felt torque? Or should I ask does the rifle twist a little while the bullet is moving through the barrel?
Rodney.

it does. But no problems controlling it off hand shooting. But shot from the bench - huhh, gives me the creeps...

Is fast twist needed for weak-kneed slow nyati.
If you got the speed, 1-18 twist gives plenty of rpms.
Starting field loads are 2500 for my 585HE.
If your at plinking speeds(1800-2400) then
penetration is not a worry.
Having a little fun from big blasts..Ed

Bench resting a 577 Trex is creepy? Nah!:



You can see that the entire underground shooting range is torquing slightly to the right.
This was done with a mere 900-grainer from a .577 Tyrannosaur with 12" twist.
This "Earth Torque" technique shields the shooter from all discomfort, and represents high attainment in the "Zen of the Big Bore."
It is a form of meditation akin to levitation and other psychokinesis, and is very relaxing.

Pac-Nor makes an 8-groove Super Match stainless .510 caliber #6 sporter contour barrel with 1:9" twist.
Standard item!
I am hoping that a 9-pound 500 Mbogo with 1:9" twist and a 570-grainer at 2500 fps will produce some noticeable torgue,
so that I may resume meditation.

quote:

You can see that the entire underground shooting range is torquing slightly to the right.

All this time I thought my monitor was out of adjustment ...