Thread: Best way to go about shooting multiple groups

Greetings 7RMBoy,
Load testing can be as simple or as complicated as you want it to be. For a start it is best to keep it simple. You have 20 rounds ready to go so start with them. Definitely chronograph them as this will tell you where your combination of projectiles, rifle and powder lot sits compared with the data you have been using. This is important as data for the 7mm RM, which I think you are using, does vary considerably. I don't believe that letting the barrel cool between shots in a group is either necessary or desirable. To me any precision lost to a heating barrel is less than that lost to getting up between shots or just fidgeting while waiting. By all means let the barrel cool completely between groups. A fouling shot before starting is a good idea, remember you are testing the load. Fire each of your 4 shot groups on a separate target and mark the targets so you don't mix them up. While shooting try to keep everything the same. The recoil of each shot is likely to push you back a little so make sure you as set up the same each time.
When you get home check your velocities against the data you have been using corrected for your barrel length. As an old draughtsman I like to do this on a graph as to me it shows the relationship between the two sets of data. As Woody suggested your velocities are likely to be a little lower. You should not run into pressure signs. At this point I would select a load towards the top of the velocity range that has a reasonable group and load 10 or a dozen rounds at that. This gives you some rounds for actual hunting and enough for a couple of 3 or 4 shot groups to verify the loads accuracy.
At this point you can decide which of the hundreds of load development methods you wish to pursue. Some at this point just use this load forever and some spend countless hours on the range testing and refining their load. Neither approach is wrong and most of us are somewhere in the middle. You just need to find your spot.
Regards Grandpamac.