K.
Wild ideas. Going back to the wind gun, use compressed air to fire a lot of bullets very quickly. Just a continuous stream as bullets are sucked into the barrel from differential pressure and ejected out. Low impact means the guns can be carried by hand, only needing new canisters as the old one is used up. Each one is good for 30 seconds of fire.
Alternatively, a coil cannon that fires shards downrange but is fairly inaccurate. Or an actual cannon that focuses on range and exploding cannonballs. (Which would be a mortar.)
Last idea would be...
Plysta Water CannonThe Plysta Cannon is a mobilized artillery comprised of a water tank, compressor tanks, and cannon/truck setup. Over half a minute water is compressed into the launch chamber behind the ammunition, in this case a fulminated mercury round the size of cannonballs, with a sturdy iron shell. On release it is fired downrange, hitting the ground and going off, creating an explosion of shrapnel from the impact. Designed with ease of operation in mind, it comes equipped with deployable walls to shield the loaders from sight. Just open the case, load the cannon and close it, direct the lift to adjust the range if nessaceery, and press the big red button once launch chamber is full. The largest advantage of the Plysta Water Cannon is it's mobility and ease of use, able to accept any ammo developed for it.
It's not really a 'lockout', it's just inefficiency. Really, doing something totally new is always going to be inefficient in some way, but it can be well worth it for the technological branching it creates.
+1