I've seen Winchester Rangers loaded with # 7.5 shot. However they were labled "For Law Enforcement only". I believe they were labled this way since they are sold to departments by the pallet load and are not labled for individual box sales. I picked up the hulls at the time since they were the old style AA's. I've since seen them as 00 buck loads also. They fed and functioned well in any gun I used, pump or auto. Generally patterning is handled by the gun and you have to see if they pattern well in your gun. But then I've always been of the school that "patterns do not kill" mentality.
On Loading information.. Generally you will not find ammo with BB's to be so light. Mainly because there just aren't that many BB pellets (.18") in 1 1/8 ounces. You will likely find them at a minimum 1 1/4 ounces up to 1 1/2 ounces. Generally, the largest shot you will see in 1 1/8 ounces will be 6's. The exception would be buckshot like #4's and 00's. 1 1/8 ounces of #4 Buck is about 20 pellets, 00 is 9 pellets.
Vince