01 December 2004, 07:37
JameisterSafe minimum fluted barrel wall thickness?
I have some fluted barrels that are thick, and some that are thinner.. I know that a minimum for the barrel thickness at the higher pressure areas is commonly considered to be one bullet diameter. that is a 30 caliber would be minimum of .60 thickness.
One lighter thin one has one caliber of barrel thickness (284) of metal about 4 inches ahead of the chamber, and with the taper it is reduced to about half that at the muzzle end. That is a thickness of .140 on each side of the barrel at midbarrel, and half that at the muzzle end. [.575 -284 = 291] - 120 fluting both sides = 171 divide by two = .085 inch at the muzzle. Any thoughts on this? it is a Hart barrel in number 1 contour.
THis barrel has been shot several times, but the recent sako issue has me wondering...
What is a rule of thumb for minimum barrel thickness at muzzle end of a fluted rifle?
Thanks for the input.
Jameister
01 December 2004, 08:02
JameisterAfer some research on this site, I find statements as to .100 minimum .125 comfortable minimum, as per Pacnor and barsness and others quoted....
Also found statements regarding the muzzle pressures as being 20% of chamber pressures....
Still, any comments are welcome..
thanks
01 December 2004, 17:15
ClarkThe 454 Ruger Super Redhawk had some problems with getting a steel that was .065" thick, could pass 1.3 X to 1.4 X the 62,000 psi proof loads, and was machinable.
They found a specialty steel that will yeild at 260 ksi, but my calculations show that is not enough [.480 * 1.3* 62k/[2* .065] = 298 ksi]. Still, they survive the proof test now.
Most people can't see that inside diameter term relating steel stress to pressure.
01 December 2004, 17:37
jeffeossojameister...
not fluted, but my savage 99 in 358 in .120 wall thickness or so from the factory at the muzzle
jeffe