Cleaning rod diameter

[Cooper4141]

I have a Cooper 57m and have a Dewey cleaning rod for it. I am wondering if the rod I have for it is too big. I think I ordered a 20 caliber rod when I got it. It measures .205. Is this too large? I don't want to mess the rifling up with the rod.
thanks

 

[Bill B]

I have a Cooper 57m and have a Dewey cleaning rod for it. I am wondering if the rod I have for it is too big. I think I ordered a 20 caliber rod when I got it. It measures .205. Is this too large? I don't want to mess the rifling up with the rod.
thanks

Assuming your Cooper is a .22, the 20 cal. rod will not be too large. Of more importance is a proper fitting bore guide and don't use too tight a patch that'll cause that rod to bend in the bore.

 

[Cooper4141]

Yes it is a 22.