at what point, from absolutely clean, does the gun start to group well, and at what point without cleaning, does the gun's groups start to open up, if at all, that you can tell?
New gun so I havent gotten to that point yet.
I have always with a new gun done a 3 or 5 shot group for each different type of off the shelf ammo I could find. Usually its 10-12 different types I try and due to time constraints and trying to let the barrel cool down between shots usually I only shoot 4 different types per range session. So 12-20 rds max.
I had never even thought of cleaning between different types until a conversation the other day with a fellow range shooter who I was watching going thru the same process but he cleaned between brands..... He said that the barrel should be cleaned between different brands to get the true results.