Went out this morning and shot 35 rounds through my thoroughly clean Krieger barrel on my Savage custom 6.5x47 Lapua doing a H4350 ladder test with 130 grain Berger VLD target bullets with the last two 3 shot groups at .2 & .3.
Now to the $64 question; if I do not clean the barrel and go back out in a few days, can I expect the same level of accuracy or do some sort of evil forces get in the barrel to affect the next shots. I have always cleaned the barrel after every shooting session no matter what the round count, so this is a very interesting question for me.
That's an interesting question, I made a study of shot string counts and down time which could produce a small book or a large pamphlet.
In short it comes down to length of down time between shot strings, velocity of your loads, shot count in the first and subsequent shot strings, moly bullets or uncoated bulletts, treated or untreated (moly) barrel, rate of twist and environmental conditions. I went with moly years ago because hyper velocity uncoated shot strings were too short in my rifles and varmint bullets.
Coming off a moderate shot string, (20 rounds for my hyper velocity, 3,900 FPS moly varmint bullets) a few days should not matter if you control humidity in your firearm safe and you were not in humid or rain conditions. I have shot accumulated strings as much as 100 rounds and saw no accuracy deterioration with my moly loads. I use moisture collecting material in my safe, Damp Rid. Depending on the rifle build you may have cold verses warm bore differences.
During varmint season with my tested moly loads I have never shot strings long enough to deteriorate accuracy, so if I'm going out 2 or 3 time a week I may clean only twice a month or if I got caught in the rain or very humid conditions. None of my varmint rifles exhibit cold barrel syndrome. They do have clean bore syndrome, I never take an unfired rifle into the field. I clean, prep for storage, pull them from the safe, dry patch and fire a round maybe 2 into the dirt, then go into the field.
I use stretch wrap in my business so if I go out and it drizzled I'll take a piece of wrap and cover the end of the barrel with 1 very tightly wrapped piece.