SPS 308 load development

[ol mike]

I have to drive 30 miles to the nearest range so going and testing loads -then go back and test the best of the last go-round -then go back and test seating depth --you see where i'm going w/ this.
Now I have a pair of Lee hand presses I take them to the range along w/ powder measure / scale etc. -I do have all the brass sized/primed and ready to go.
Myself I start a couple of grains below a book max charge and load rounds in 3/10gr increments .This advice is based on 308 & '06 cases NOT big magnums -meaning don't start a couple of grains below book max w/a RUM...
I shoot the first round then draw a picture on notebook paper where the round landed -shoot second round -document where it lands on target and marked as shot #2 -right on up -watching for signs of pressure until I have worked my way up to max load.
If you get lucky you will have to shoot at more than one target dot because the bullets are hitting in the same holes.
Marking and numbering each shot will allow you to see which powder charges shoot together on the target and you checked the pressure on the way up to max load.
Now use whatever regimen you want to -loading up a few of the rounds of each powder charge and see which charge level out performs the other .Load rounds that are close to one another in charge weight - say max load is 44.1gr -you start at 42gr then four shots later load 43.2 lands near 42gr load DON'T load 42gr and 43.2gr to compare performance --only compare shots with powder charges in sequence -example or 43.5gr and 43.8gr loads- bullets land very close together -then load some of those two charges and compare performance . Better yet 43.5 -43.8 and 44.1gr all land close together.
Once you have settled on that start working on seating depth --say you started 20K off the lands -try some groups w/bullets at 10K then 30K off the lands to see if the barrel has a preference.
I have worked up great loads in one day using the Lee hand press at the range where it use to take me three or four range days -a reloading set-up that can be taken to the range will pay for itself in gas and tires several times over.
Also leaving the range w/a good baseline load and a rifle that is sighted in and ready to rock is a good feeling -now it's time to stretch her legs and get started working on a long range drop sheet .

P.S. If you have a powder/bullet combo that is shooting 4" groups at 100yds. and two shots happen to land together -don't waste your time with a group like this -if a barrel likes a powder/bullet combo it will shoot pretty good with all the charge weights - tempermental grouping is trouble -time to try a new powder/bullet.

Good luck -Mike

[Damascus]

You're method is very similar to mine, however I fire groups of a certain charge, not one at a time... What happens if you're best load happens to be 43.3 gr., and after the 43.0 shot; you accidentally pull it a little? You'd think it didn't work well - firing at least 2 shots, so you'll know the rounds really are impacting there... You mentioned a valuable step in your method that I forgot to mention in mine - marking your points of impact in your data book - invaluable reference material.
Also, don't forget to chrono those loads! Loading in the dark ain't fun Just because your aren't seeing pressure signs, you might just have a very well-built rifle that has a tight bolt and lockup, and isn't allowing as much head-expansion or leaking primers as usual... A chrono is the best way to see when you're approaching the maximum threshold.. I loaded for a few years without a chrono, and after I used one once - I'll never develop another load without it!