I always been able to tell subtle differences in recoil among the same caliber when shooting different loads in most of my guns but never anything major. A few days ago I took my new LC9S pro to the range with 2 different loads. Strange thing was it felt like shooting 2 entirely different calibers. My standard go to target load is a reload 115g bullet behind Winchester 231. I ran about 100 rounds of that though the LC9s and thought it felt a bit snappy but mainly attributed that to not having shot small 9mm's much recently. I then switched over to my go to self defense load which is the 147g Federal HST. The difference was amazing. The 231 load felt snappy almost like a .40 and the HST felt pushy like a .45. The thing I am trying to figure out is if it has more to do with the powder or the heavier bullet. I'm thinking I want to pick up some 147g 9mm's to load just to test as I actually enjoyed shooting the HST's more than my own load. Any one else experience anything like this?