From two previous posts:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
https://www.thehighroad.org/index.php?threads/quickload-user-forum.724152/#post-9044303
QuickLoad is as sliced bread to those who use it intelligently. It provides
information/options/consequences/projections that nothing else does
in this business. Absolutely nothing else at all.
HOWEVER: QuickLoad goes most effectively with a
chronograph. Without
it the shooter is operating no less blindfolded as he is just blindly following
a manual.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
http://castboolits.gunloads.com/sho...nd-QuickLoad&p=4333578&viewfull=1#post4333578
30-40 Krag, RETUMBO, and QuickLoad
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 #301_SAECO 301_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:
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 ± 0
7 (wow)
So again: (1) Quickload as a computer-driven internal ballistics model (2) Basic learning curve in "safe" regions (3) rational calibration looking at other people's examples/data/experience "even internet" (4) and a CHRONOGRAPH (stomp, stomp)
One for the search engines then.....
(YMMV, of course. Take great care)