By Dave Affleck (DAA)
Determining which powder to use is always my first step. Pick a good
bullet - a proven performer for whatever cartridge/twist you have, Fowler
or Berger 52
for a 14 twist .22-250 for instance. Or, maybe you have a big supply of a bullet that you are bound and determined to use - in such a case finding the best
powder for that bullet becomes even more important. I've got thousands of 50 and 55 Vmax on the shelf for instance, and often just use them and never try
another bullet - just because I have so many of them. Note, if you really need to test more than one bullet, which is not unusual, always start with the heaviest
bullet. That way, you can use "max" for the heavy as "starting" for the lighter ones.
Determine "jam" length. If you are comfortable loading with bullets
contacting the lands (I am), back off .005 from "jam" and that's a good
seating depth to
start with (the bullet will still be in firm contact with the lands at .005 off "jam"). If you would feel better getting the bullet back off the lands I reccomend a
solid .005 off to start (I do NOT like loading at the proverbial "just kissing" point - way to indefinite). NOTE - there are exceptions to everything, but, I've
found best accuracy is almost always found either with firm contact into the lands or not more than .010 jump (there ARE exceptions!). Have read from
reliable sources that .22's usually shoot best at .020 off the lands but in exhaustively testing half a dozen centerfire .22's, I found .020 off the lands has usually
been where groups really start going to shit - I don't reccomend it as a good starting point based on my own testing.
Choose some powders to test. However many or few you feel like playing
with. I usually choose not less than 3 and not more than 5 powders to begin
Now, here's where my load development technique starts to get tricky.
Well, not really tricky, but it is MUCH, MUCH easier to do if you are setup
to load at
the range. Which is why I always recommend starting out with Wilson dies and a good repeatable powder measure instead of buying an "RCBS kit". But
that's a whole nuther ball of wax...
For each powder you want to test, begin with the "starting load" and
your chosen bullet at your predetermined seating depth (just into or just
off the lands but
NOT "just touching"). Load one round at a time, increasing the powder charge for each case (no two will have the same powder charge). Start shooting them
into a group. Keep going until you have reached "max". Use your own judgement on what "max" is - if in any doubt, don't go above the published data you are
using. I always do this testing over a chronograph, so I'll very quickly know what the max charge and velocity is for each powder I'm testing. Do this for each
powder. After shooting this series of groups, I usually know which powder is going to work best. If shooting was done over a chrony, you'll know how
velocity stacks up for each powder. You will also have fired a "group" with each powder, I generally end up with about 10 shots in each of these groups
(typically in .2 or .3 gr. increments). That's a 10 shot group with each shot having a different powder charge. Guess what? If doing this shooting at short
range, like 100 yd's, you will very often find that one or more of the powders produced an amazingly small group for each shot having a different powder
charge - I've literally drilled 10 shot "one holers" doing this kind of testing at 100 yards. By the same token, it's likely that some of the powders will have really
laid down shotgun patterns in this test. It's my belief that generally speaking, the powder which produced the smallest group with each shot having a different
charge weight will also produce the smallest groups when all the shots are weighed the same (as with everything else, there ARE exceptions!). Or, at least I
can plainly see it's not a tempermental combo and will be easy to work with.
Note - depending on intended application, I USUALLY like to do this
testing at 300 yards or greater. Some of the data you can obtain and observe
range is completely lost at close range. Not having time to go into any detail, put it this way: If you intend to use this load at 500 yards, I recommend you do
this testing at 500 yards. Vertical which may not show up at all in 100 yard shooting will be way evident at 500. Also, on a related note, and again no time for
detail, strange but true: The load which gives the lowest velocity spread and SD is not always the load which gives the least vertical dispersion at long range.
Moral of the story, if you intend to shoot long range, TEST long range!
So, in one whack, you have quickly determined which of the powders tested
will likely give best accuracy, what the max. load is and what velocity
From there, simply "work down" from the max load shooting groups to determine the most accurage charge weight.
Fine tuning with seating depth is a logical next step.
Primers can make a big difference, no doubt about it. But I generally
don't monkey with them except as a last resort. I've rarely had to go that
far, but it
Please note, there are about a zillion different ways to skin this cat
and the method I've just quickly laid out here isn't always going to be
the best way. I don't
even always do it this way myself. It's simply one of many schemes that will get you to the same destination. It's a logical and organzied methodology, but not
necessarily the most logical or organized. Certainly not necessarily the best. The conditions and variables that come into play which may make it advisable to
do things completely differently are so varied and vast that I doubt they could all be covered in a book the size of Websters. Even just the variations on this
methodology are virtually unlimited. My point being, none of this is written in stone and I don't take issue with anyone that disagrees with any of this.