I have not shot the L on any semi guns, only bolt guns. It was very impressive on a 300 win bolt gun. Like everything it's going to be a trade-off. Length and weight vs. sound reduction, etc. I would say the L is fantanstic for guns on bipods and on a bench. The K is fairly loud compared to the S, especially on shorter barreled guns like an 11.5. Right now mine basically lives on a 13.7 gun and I'm very happy with that set-up. With you wanting a can for a bolt gun, and the S is Handy enough for you an L and and S doesn't sound like a bad combo. I basically impulse bought the K due to the HPA pricing they offered.