What method

chuff

Sergeant
Full Member
Minuteman
Feb 25, 2009
121
0
SW Colorado
is everyone using for new load workups? I just picked up a Savage model 12 in 223 last week and I've been working up loads using the "ocw" method. It's my first time using this method, and it seems to be working pretty well although it does require a lot of rounds for each string. I'm curious what method others are using and prefer.
 

Fuzzball

Gunny Sergeant
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Minuteman
Jan 19, 2009
2,162
6
Re: What method

I use the ladder method first. Mostly to eliminate the charge ranges that are obviously non-productive. Then use the a narrow OCW test series around the best ladder charge to optomise it.

After dialing in on the best charge, I do it again with seating depths. Rarely takes more than maybe 50-60 rounds to find my load or I abandon the powder or bullet entirely.

I no longer try a lengthy ladder charge test range. I'm only interested in accuracy at the top or near top velocity loads so that greatly reduces the range of charges I have to examine.
 

kombayotch

Gunny Sergeant
Full Member
Minuteman
Sep 20, 2007
1,852
42
Re: What method

I use Pressure Trace. Chris Long wrote the software routines that show the exit times. OBT nodes are shown and you just tune the load to line them up. These match up pretty well with what I get from doing an OCW test, but it takes me less than 20 rounds usually. Plus, I can do on a 20 yard indoor range 24/7 regardless of weather.

I fire a group at the starting weight, then work up firing 1 round in 1 gr. increments till I get to max pressure. Then I fire another group. I then take the charge weights and exit times of the two groups and interpolate them to find the charge that give the OBT.

Example PT results:

load.jpg


load2.jpg


I load a bit slower than OBT when developing loads in colder weather.
 

Greg Langelius *

Resident Elder Fart
Full Member
Minuteman
Aug 10, 2001
9,129
5,610
AZ
Re: What method

I do three stages of load development.

The first involves either research to determine reasonable max and min as-published charge levels for the powder, bullet, and casing; or cautious pressure testing if no such published data is available.

The second stage involves working down from relatively near max (I'd suggest 95% of published max) in relatively broad (I'd suggest 2%) charge increments, to see if any accuracy nodes suggest themselves.

The third stage involves load refinement, experimenting with small charge increments in ranges closely bracketing the suggested node charge levels, and maybe also experimenting with issues like OAL.

Some basic rules apply.

Long experience has shown that max and overmax loads are tempting but neither necessary nor wise. All excesses always carry penalties, they just don't seem so apparent at the time.

When nodes appear at or near max, jumping the bullet is preferable. When loads are comparatively tame, seating into the lands can be considered.

Component substitutions and component lot changes require at least some preliminary load verification before leaping ahead and blindly assuming the load recipe has not been altered subtly and unwisely by the change.

There are no secrets or magic tricks. Nothing is true until proven so, no matter how intuitively 'right' it may feel. Fortune favors the cautious handloader. When in doubt, disassemble the batch and start over; never, ever, leave this step for later.

Greg