AggieMM wrote:Thanks for your input. I posted the summary above, here is the "raw data sheet".
Chrono Log - 8/9/2007
Group 3 is the one I like. Group 4 got too close to the floor for IDPA of 850 fps (using 147g bullet).
Tom, after you review the data above, I'd love to hear your thoughts......
Ryan
Ryan,
Well, my first obsevation would be to borrow whatever your brother has and use it.
Secondly, I have found that I get better (i.e. more realistic) readings when I use 10 shots rather than
5 for my groups. I have had some serious divergences in readings between the 5th and 10th
shot in a string. And in doing some recent reading on SD the consensus is to always use at least 10
data points of whatever you are testing. I started out using 5 too but always now use 10.
While it has opened up the SD and ES I feel that it has also given me more realistic results.
It also helps to explain (an alibi for) that occasional flyer.
Do you know the number of shots required for IDPA or IPSC to confirm that your loads are meeting
the minimum power factor? I don't which is the reason I am asking.
I would suggest that if all shots have to be over the minimum, and you are one or two SD's away
from minimum (from your lowest reading) with a 10 shot group, that you are in good shape.
If you are up to more shooting take your best two groups and shoot some 10 shot groups with those loads.
This will either confirm that you have great loads, which at this point seems to be the case,
or that you need to try a few more.
One other thing regarding the powder charge. I have not found that keeping the charge within one tenth
of a grain has been a useful exercise. It is very difficult to do and is not all that necessary for the type
of shooting that you are building loads for. Use your targeted load weight as a center point and just try to
stay only one tenth away from that center. It won't have a lot of effect on your results and may save
a bit of time and frustration.
Anyhow, loosen up a bit on your requirements, do more testing and don't get discouraged when your
results go nonlinear. Remember that at the core of all this there is a science. Finding it (the journey)
is the fun part.
BTW - I still keep all of my data in a spiral notebook, with pencil entries.
Your method appears to be superior in all respects. Good Job.
Kind Regards,
Tom