What he said....
Only may I add, move your target out to at least 75 yards if not 100 if you have a good scope and shoot your groups for score at that distance any flyers will really show themselves instead of shooting at 50 and wondering if that one 3/4 inch out was you or not, you will know at distance and shoot at least 5 to start with before shooting for score then shoot 5 groups of 5 of the top three performers from the 50 yard line.
The lube is a big deal, do not discount the cci sv or others with seemingly thin or less slippery lube as it may take a few more to season the barrel before it settles in with a particular ammo.
When I am doing this sort of testing I clean my rifles with kroil until no lead or black on patch the a couple dry patches, then either acetone or rubbing alcohol followed bu another dry, it may be unnecessary but to make sure I get all the lube off from the previous ammo I do it anyway
Great point. Some ammo will group great at 50m and then be a disaster at 100m. I mostly use these distances because I shoot NRA Smallbore Silhouette and 100m is the furthest I shoot.
In some rifles I've shot 2 different types of ammo, one at 40m and 60m, and the other at 75m and 100m, some group better than others at different distances. In some cases one ammo will shoot good at all distances.
So yeah, stretch it out if you are shooting further.