Some people just bolt the ammo cans to the fender bracket bolt holes without using separate brackets. You need to decide if you want them tight to the fender, or sticking out a little. You can add washers or spacers if you want. Here is a post: https://www.facebook.com/groups/1098193840710040/permalink/1257683011427788/
If you are buying AMMO cans, consider getting plastic ones. Two steel 50 caliber ammo cans weigh 10.6 lbs. (4.8 kg), enough to slow your bike down a little. Two plastic 50 caliber ammo cans weigh 3.5 lbs (1.6 kg).
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