Post by Aggie01 on Nov 4, 2009 15:16:57 GMT -5
With king6's recent 414 project and Lee Martin's latest project being mentioned, I thought I'd ask/bring up this topic all on its own.
My own musing/number crunching/calling people on the subject has led me to believe that a 5 shot cylinder in a full size Ruger Blackhawk is overkill on a .41.
Simple maths:
John Linebaugh's position that a .45 Colt Ruger is 80% as stong as a .44 magnum has been widely accepted.
.45 colt "tight chamber" =.480 dia.
.44 mag "tight chamber" =.460 dia.
.41 mag "loose chamber" = .440 dia.
Can we then assume (I believe so) that a .41 magnum in the same cylinder is 20% STRONGER than a .44 magnum?
If this single assumption is right, that means in the full size blackhawk we can easily push pressures to almost 48K psi.
Do we need more? Of course we think we do.
It's well understood that to increase cylinder strength of a big bore, that it needs to be five shotted both to ensure sufficient material between the cylinders, and to allow the bolt notches to fall between the chambers.
In the Ruger Blackhawk the bolt notches are actually offset from the centerline of the cylinder just a little. Not enough to get them out of the way for the big bores, but enough that for a middle bore, the bolt notch (I need a diagram here) is slightly further away from the nearest point of the chamber than just the reduction in chamber diameter, which means it actually is "stronger" than the earlier proposed numbers.
More food for thought - apply the same logic to the .357 magnum in the full size ruger. My math says it's 180% as strong as the .44 magnum. (68K pressure capable
) That is nipping at the heels, if not running neck and neck with the much lauded FA 353.
IIRC, primer pockets get loose at these pressures, so the gun is not the limiting factor anymore... A 70K .357 load only has about 5 tons of case head thrust - not far off a .475, so frame strength is a non issue in this equation.
Anyway, had a headache today, thought I'd pass it around.
My own musing/number crunching/calling people on the subject has led me to believe that a 5 shot cylinder in a full size Ruger Blackhawk is overkill on a .41.
Simple maths:
John Linebaugh's position that a .45 Colt Ruger is 80% as stong as a .44 magnum has been widely accepted.
.45 colt "tight chamber" =.480 dia.
.44 mag "tight chamber" =.460 dia.
.41 mag "loose chamber" = .440 dia.
Can we then assume (I believe so) that a .41 magnum in the same cylinder is 20% STRONGER than a .44 magnum?
If this single assumption is right, that means in the full size blackhawk we can easily push pressures to almost 48K psi.
Do we need more? Of course we think we do.
It's well understood that to increase cylinder strength of a big bore, that it needs to be five shotted both to ensure sufficient material between the cylinders, and to allow the bolt notches to fall between the chambers.In the Ruger Blackhawk the bolt notches are actually offset from the centerline of the cylinder just a little. Not enough to get them out of the way for the big bores, but enough that for a middle bore, the bolt notch (I need a diagram here) is slightly further away from the nearest point of the chamber than just the reduction in chamber diameter, which means it actually is "stronger" than the earlier proposed numbers.
More food for thought - apply the same logic to the .357 magnum in the full size ruger. My math says it's 180% as strong as the .44 magnum. (68K pressure capable
) That is nipping at the heels, if not running neck and neck with the much lauded FA 353.IIRC, primer pockets get loose at these pressures, so the gun is not the limiting factor anymore... A 70K .357 load only has about 5 tons of case head thrust - not far off a .475, so frame strength is a non issue in this equation.
Anyway, had a headache today, thought I'd pass it around.
I've often thought about much higher pressure 357's in my Ruger Redhawk. Since the cylinder is huge and the chamber wall thickness is unreal it got me thinking! I could never find reliable load data for the FA353 to even try it so I never got the chance before selling the gun last month. But I would like to know the answers to some of your questions as well. It seems every time FA chambers a cartridge in their large frame gun with the 5 shot cylinder people start loading the cartridge to 353/454 pressure levels. There just doesn't seem to be much talk or testing of what 357 and 41 magnum guns in 6 shot cylinders can do. It all seems to be reserved for the differences between the 44 magnum and the 6 shot 45 colt.
