Quote:
Originally Posted by tasco
Hopefully I am not hijacking this thread, and adding some useful info. I am very new at this Load development. I am also not a very good shot and need to spend more time behind the trigger. I read about the 10 round load development test, I liked what I saw, and thought why not, it will take out the initial precision component of load development, especially with the winds we've been having. I found it very interesting the trend in velocity vs load charge. Sure I needed to purchase a Magnetospeed to accurately do this, but heck its an expensive hobby so why not. From here I can pick my best velocity node and try several groupings at a target and hopefully have a hunting round that this gun likes. in my test I went up in .3 grain increments and fired 27 rounds till I had some pressure issues.
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You may be very new at load development but you are certainly on the right track and posting just what this thread needed. The graph clearly illustrates the pressure spikes which are usually followed by a leveling off of pressure for a couple of increments. If you were shooting on a target loads 41.2, 41.5 and 41.8 would group into a small cluster if you are shooting up to your rifles potential. While you are not up to Hornady's Max charge of 44.0 grains you are over their max velocity of 2700 fps for various 150-155 grain bullets. If you load 5 at 41.4, 41.5 and 46.5 respectively you will likely find the most accurate load over a range of conditions and the load with the lowest ES and SD which will likely be single digit. You will also have a load that is easy on brass if properly FL neck sized as it will likely not be fire-formed at the base enough for your dies to size.
If brass life is not a concern and you want more velocity you have another stable node between 43.3 and 43.6 which is about 2 grains below where you started getting pressure signs and where I would have stopped. Load 5 at 43.4 and 43.5 and you should find the sweet spot which could be further tweaked by seating depth. However you will likely want to neck size the brass in which case you will want to start another ladder at 43.5 grain and work up a load for that situation.
Here is a pressure ladder that I shot. Loads 22.0, 22.1 and 22.2 grains clumped into 0.6" followed by pressure spike which took 7,8@9 out of the group. I had no pressure signs but the brass was close to fireformed, the primers were begging to flow and the case was full.
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