For chukars, try Remington STS Light Handicap Trap loads in #7 1/2 (1 1/8 oz shot, 1200 fps). No need for extra speed, as that speed actually tends to open the pattern vice keep more shot in it. The reason these loads pattern so well is the very hard shot, close tolerances for the STS target ammo, moderate velocity.
On pheasants and other larger birds, I like the old live pigeon load of 3 1/4 1 1/4 #5 or #6 (the latter if your gun will pattern it well, as it will give more density in the patterns). These travel at 1220 fps and are a classic.
