ALWAYS start at the minimum and use Powder data
no-one is suggesting you work up 5 round groups of each 0.2gr increment
personally I work from minimum but the lower ones are in much smaller quantities
I am discounting pressure issues at these levels not hunting for 5 round groups
often only one or two rounds (one is fine for me personally but not a representative number should there be an anomaly)
I use 0.2gr incrments in .222
I use 0.4gr or 0.6gr increments in .270 and 300WM
once an accuracy node is indicated I may fine tune either side of that in smaller increments...but usually don't
Looking at VV data for 130gr .270 using N160 (a combination tried and tested by myself)
8,4 | 130 | SP | Remington | 82,0 | 3.228 | N160 | 3,34 | 51.5gr | 847 | 2779fps | 3,76 | 58.0gr | 940 | 3083fps |
Low of 51.5gr
High of 58.0gr
a 1gr increment from low to high will see you with 8 charge levels
do 5 of each and you are a good way to half a box of bullets and primers!
a 0.5gr increments and 3 of each is 42 rounds!
5 of each is 70 rounds!
be there all bloody day!!
It is unlikely that you are looking for a 2770fps load so starting at this level is a safety concern not an accuracy one
I check the case and rifle operation for all the levels to exclude issues.
I personally would probably load the following combo in that scenario
1x51.5gr
1x52.5
3x53.5
3x54.5
3x55.5
3x56.5
3x57.5
1x58
if I hit a sweet spot half way through shooting that lot I would more than likely stop there, use the best charge level and tweak OAL, maybe tweak charge either side.
pull the rest of the high loads with a kinetic hammer and use the powder and components on a known accurate load
awful lot of people shooting this combo at between 54.5 and 56.5gr (me included)...why waste time and powder looking for a hotter load?
that's just my view,
people may/will disagree,
but I am pretty happy with the accuracy of my loads and none of them with the exception of one are anywhere near book max (and even that one is much slower than the book would indicate!! 78gr H1000 under 208gr Amax in 300win mag)
never had to lift a bolt with a hammer and my brass lasts an awfully long time!