Process of elimination I guess.
The BSA CF-2 in .270 is its own kind of fun because we're old friends and I load a laundry list of purpose built ammunition for it. It shoots everything from cast and varmint rounds to the common 130 and 140gr to the 150's for larger game to a round nose 160.
The fun here is I know where each point of impact is and it just does its job in near boring fashion.
The 1851 replica. Fire smoke and brimstone with accuracy that rivals my Colt 1911 Ser. 70 Mk IV Gov.
The Hi-Power looking thing is actually a FEG P9R 9mm. The bastard step child of a Browning Hi-Power and an S&W model 59. Trigger is superb in DA and SA. Fun? Again it just goes where I point it. Ball ammunition with a reasonable ES will allow a 6" group, at 100 yards.
The 1908 Colt pocket .25ACP isn't any fun. I can't hit a tin can ten feet away. It's near impossible to load for and expensive to shoot.
Finally there is the BSA, Martini- Enfield custom in (of course) 303 British. Fun!
It goes where it's pointed. I load 175-180 for it and it gives a satisfying thump on steel out to 300. (when I can see that far) It's a center divot, Buckhorn rear leaf with wedge. The front is a tiny gold bead. (doesn't tarnish so it must be gold) The wedge of the Buckhorn is regulated for 180gr windage. If you know how to really use a Buckhorn and bead you know what I'm talking about. The action is tight and headspace minimal. Everything inside the action was polished and loved on by someone that would not settle for "good enough". Trigger is just over 3# and approximates the surprise of a well tuned N frame S&W. Extraction and ejection is flawless. Appearance is about a "3 foot rifle" . If you look close the polish has a few lines in it, the original markings are faint, and a few edges are rolled over. As nice as the wood is there are a few runs in an acrylic finish and a few inletting sins.
So, Fun? The BSA Martini-Enfield wins. It is so fun It was gifted to the bride. Aside from the expected recoil she is beginning to understand why I enjoy it so much. Then again she thinks the Colt 1908 pocket .25ACP is fun.
As always, YMMV.