Sean Connery’s ‘007’ preferred the Beretta .25.
I once read a story by the real “Q” or Major Bootheroyd which was his real name.
He read one of the Bond books and wrote a letter to Ian Fleming telling him that he had mis-named the Beretta .25, by calling it a 6.75 cal. He also said a real agent would not carry a .25 auto.
He and Fleming kept up correspondence and eventually met and did some target shooting. Bootheroyd said that Fleming was not knowledgeable on guns but despite that was an excellent shot.
It turned out that the owner of Purdey shotguns had already corrected Fleming on the caliber. Fleming asked the Major what gun would actually be used and he replied, “A Walther PPK, in .32 caliber.” Fleming made the correction in “Dr. No” and used the Major’s real name.
At first. He was persuaded to switch to .32 as I remember. Walther, I believe.