Best Methodology for Decreasing Group Size?
Posted: Sun Dec 17, 2006 5:58 am
I know this has probably been covered in bits and pieces elsewhere, but I am trying to get this whole thing straight in my head (I'm new to the reloading game in case you can't figure it out by reading my post).
Let's say, for the sake of simplicity, that you have a custom made gun which is as accurate as humanly possible and it is mounted on a device that takes all shooter error out of the equation. You are trying to work up a load for this gun where accuracy is paramount and speed is secondary. If you were trying to do this in the least number of attempts what is the methodology you would follow. In other words as you are working this down what variables what areas give you the best bang for the buck (or in this case the most accurate bang for the time spent). Based on what I think I understand from reading about a million posts I think it would go something like this (but I'm sure one of you guys who actually knows what they are doing will correct me):
1) Vary powder in .5 grain increments and find tightest group. Once you find best range try .01 increments in this range to get absolute best?
2) If none of these give you good results try a different powder.
3) If none of the powders give better results, try a different bullet (maybe this should actually be #2 - it seems like a lot less of a hassle).
3) Start changing bullet seating depth from start point in increments of X to see if that tightens groups. What is a reasonable number for X?
4) Try different primers?
5) Try different brass? This one really confuses me when I read about guys sorting the brass by weight. I get the concept - if they are all the same length but the weight varies then the internal volume must be variable. So now that I have them weight sorted, what do I do to accomodate the various weights - use slightly more powder in the cases that have a larger internal volume? If so, how the heck do I determine how much more (trial and error I assume). Then I keep some kind of log book with various powder loads for brass of various weights? This seems like it could drive a guy into a padded room quickly.
Am I even remotely correct here?
Let's say, for the sake of simplicity, that you have a custom made gun which is as accurate as humanly possible and it is mounted on a device that takes all shooter error out of the equation. You are trying to work up a load for this gun where accuracy is paramount and speed is secondary. If you were trying to do this in the least number of attempts what is the methodology you would follow. In other words as you are working this down what variables what areas give you the best bang for the buck (or in this case the most accurate bang for the time spent). Based on what I think I understand from reading about a million posts I think it would go something like this (but I'm sure one of you guys who actually knows what they are doing will correct me):
1) Vary powder in .5 grain increments and find tightest group. Once you find best range try .01 increments in this range to get absolute best?
2) If none of these give you good results try a different powder.
3) If none of the powders give better results, try a different bullet (maybe this should actually be #2 - it seems like a lot less of a hassle).
3) Start changing bullet seating depth from start point in increments of X to see if that tightens groups. What is a reasonable number for X?
4) Try different primers?
5) Try different brass? This one really confuses me when I read about guys sorting the brass by weight. I get the concept - if they are all the same length but the weight varies then the internal volume must be variable. So now that I have them weight sorted, what do I do to accomodate the various weights - use slightly more powder in the cases that have a larger internal volume? If so, how the heck do I determine how much more (trial and error I assume). Then I keep some kind of log book with various powder loads for brass of various weights? This seems like it could drive a guy into a padded room quickly.
Am I even remotely correct here?