Some interesting perspectives from Bret Contreras here. Note, the experiments he conducted were on himself and his clients, who I would imagine, would have the ability activate their hamstrings and glutes more than most due to his obsession with glutes! Anyway, still some interesting stuff here:
Kettlebell Swings: Go Heavier for Greater Glute and Hamstring Activation | Bret Contreras
From the article the biggest statement to note:
Swings produced a large horizontal ground reaction force
Contreras hypothesised that swings would produce a greater horizontal ground reaction force than Olympic lifts and jump squats. What this means in a practical sense is that kb swings could potentially improve movements with a large horizontal forces such as sprinting, rucking in rugby, long jump, etc. However, the kb swing has not been researched to show an improvement in sprinting mechanics or any other movements. Moreover, studies comparing exercises with a large horizontal GRF would be interesting: swings, hip thrusts, deadlifts, broad jump etc.
Researchers Lake and Lauder, showed that 32kg kettlebell swings had a large horizontal component and larger net impulse (impulse = force x time) compared to back squats and squat jump. Essentially, impulse is your ability to apply force quickly, which is important in any power sport.
However, as Contreras noted in his article, there is a "sweet-spot" in loading the swing for power production. In the aforementioned study the researchers used a 16kg, 24kg and 32kg. Peak and mean propulsion phase power comparing 32kg swings and squat jumps were similar but, when the participants used the lighter kettlebells the jump squat power was greater.
What I would've liked to see in this article is a 40kg and a 48kg kettlebell used. I reckon their would be a drop off in power generated as there is more than likely due to the previously mentioned sweet-spot in power production. This would go a long way in helping loading parameters in the kb swing.
Lake, J.P., and Lauder, M.A. (2012). Mechanical demands of kettlebell swing exercise,
Journal of Strength Conditioning Research. 26(12), pp. 3209-3216.