Still playing with cast in the original-config 29" Krag, I've gone through multiple bullet designs/weights/velocities/powders... picky and fickle.
Finally seemed to settle a bit on a 190gr SAECO TC-GC in #2 using Winchester 780 Supreme ... which of course is now no longer made... And still it exhibited significant velocity swings depending on powder position in that relatively large case for the intended pressure (28ksi) velocity range.
The heck w/ it.
Ask QUICKLOAD for the best combo of
- Pressure (target 28,000 psi)
- Velocity (target 2,200 fps)
- Case Fill (103-108% to insure complete fill/slight compression)
- Burn (mid 80s and up...)
QuickLoad spits out a reeeeeeeaaaaally long list, which w/ a little filtering:
(Hopefully, this passes the Forum Terms-of-Service Test)
Problem is. there is NO published (manufacturers' or even WAG internet) data on that kind of "ridiculously unsuitable" powder/bullet/cartridge combination.
So I dig out a Berger manual which does use RETUMBO and a 190gr bullet -- for the 300 RUM. OK, what does Quickload predict for the RUM ?
Turns out it matches dead nuts on w/ Berger's data; and is reasonably consistent with interpolated Hornady and Lyman data at both MIN/MAX levels and pressure/velocities,
So we go ahead and scale it down for the Krag and take it out this evening:
(actual Oehler velocity: 2,173 ± 07 (wow)
One for the search engines then.....
(YMMV, of course. Take great care)
.
Finally seemed to settle a bit on a 190gr SAECO TC-GC in #2 using Winchester 780 Supreme ... which of course is now no longer made... And still it exhibited significant velocity swings depending on powder position in that relatively large case for the intended pressure (28ksi) velocity range.
The heck w/ it.
Ask QUICKLOAD for the best combo of
- Pressure (target 28,000 psi)
- Velocity (target 2,200 fps)
- Case Fill (103-108% to insure complete fill/slight compression)
- Burn (mid 80s and up...)
QuickLoad spits out a reeeeeeeaaaaally long list, which w/ a little filtering:
(Hopefully, this passes the Forum Terms-of-Service Test)
Problem is. there is NO published (manufacturers' or even WAG internet) data on that kind of "ridiculously unsuitable" powder/bullet/cartridge combination.
So I dig out a Berger manual which does use RETUMBO and a 190gr bullet -- for the 300 RUM. OK, what does Quickload predict for the RUM ?
Turns out it matches dead nuts on w/ Berger's data; and is reasonably consistent with interpolated Hornady and Lyman data at both MIN/MAX levels and pressure/velocities,
So we go ahead and scale it down for the Krag and take it out this evening:
(actual Oehler velocity: 2,173 ± 07 (wow)
One for the search engines then.....
(YMMV, of course. Take great care)
.
Last edited: