Barrel for 41
If you have any thought of shooting ISSF competitions (Standard Pistol, Sport Pistol, or Rapid Fire), then get the 5 1/2 inch barrel. The 7-inch will not fit within the regulation test box. The 5 1/2 inch barrel will still be suitable for NRA Conventional Pistol and even at 50 yards, shooting one-handed (per the rules), you will not likely see any difference in score. At 25 yards, the shorter sight radius of the 5 1/2 inch barrel will be an advantage in Timed and Rapid fire.
MT