Rotaryworks has a very long stroke, and can also be a very fast machine (depending upon which motor you get for it). Many people enjoy lining with it. It has NO problem with very large mags or rounds.

Extra long stroke neotat vivace also has a very long stroke, hits very hard, and can be made faster or slower if need be, to accommodate your hand speed. Both are lateral slide machines, making them feel very stable for groupings from 14rliners down to singles.

Dan Kubin makes a great machine, the cranker. It also has a long stroke and hits very hard. I've used it for lining with 14rounds and 5rounds with much success.

Those are the favorite that I own. They don't have adjustable give (though the cranker has a little bit of 'slip' which is nice), so they will all hit hard, if that's what you are looking for.