Every now-and-again I give my centerfire rifles a really thorough bore and chamber cleaning down to bare metal....
When I get them back to the range, I always see these range results following the deep-cleaning:

- Some of them start grouping well, right after one or two fouling-shots.
- But, a few of them need 10-20 shots to “settle-in”, then group well, and continue to group well in following range sessions.

Why do some barrels need those extra rounds through them following a deep cleaning?

Thanks in advance for your replies on this!

Cheers.

Because they’re all individuals...

I have seen the same thing, especially with a 22LR. Depends on the barrel I guess, some need more fouling than others to "settle" in. To me, the first cold bore shot is the money shot, except for 22LR target rifles. Then I want consistent grouping.

To refill the tool marks, rough spots, pits, with the copper/gilding metal you removed cleaning the barrel down to bare metal. Some barrels will shoot better slighly fowled rather than when they are squeaky clean.

Makes sense.
Thanks for the education!

I've long ago taken JBs advice and stopped cleaning rifle barrels so much

I’m inclined to join the club.

X2 i don`t clean my rifles or my shotguns much i just wipe my rifles down some

The one & only time I cleaned my favorite 300 WSM, it needed12 rounds before it settled back in. I was starting to fret. Had me concerned. Have not cleaned it since. That was about 400 rounds back. Still driving tacks.

Same. Don't need to be making any more work for myself.

Good to read that I'm not the only one who has seen this and I always thought that it was just me having had too much coffee or something might have been loose. A Shilen custom barrel should not be full of tool marks, rough spots or pits and a synthetic stock shouldn't be moving around either. I know now that I was cleaning too often lots of times only after a few rounds to confirm the zero. Minute of a whitetail brisket, but a little disappointing on a target.

JB wrote an article where he talked about a rifle he had that he couldn't get to shoot. He was at the range and decided to just shoot a bunch of rounds to see what happened. He shot something like 25 or 30 rounds and it started grouping. I would never have that much patience.

With a new gun or a new barrel, I clean to bare metal after each range session until I have about 200 rounds through. After that I clean just enough to get out any excess fouling. Just me.

I will have to quote Big Stick, "Cleaning before your groups open up is like wiping your but before you take a dump" Most rifles will tell you how often they want to be cleaned by the results on paper. Having said that I was raised to clean after each trip to the range. I now believe we should pay the most attention to the "cold bore shot" I see on Utube many folks speak of warming the rifle up before shooting for groups. For hunters the first shot from a cold bore should be on target and the rifle will tell you if that is from a clean or a fouled bore.
Pavementends

My Rugers prefer a dirty barrel, and I have heard others say the same thing.