why do slugs kick harder than equivalent shot?

[ArmedBear]

Fluid dynamics would matter at the forcing cone and at the choke, WRT felt recoil.

So, the question is, do you feel the recoil of a slug differently with a cylinder bore vs. IC or M choke?

If not, then there is no perceptible effect.

 

[Dr. Tad Hussein Winslow]

Basic physics can ALWAYS be explained in scientific terms.

Equal ejecta is equal recoil in same firearm. Simple.
Ejecta is payload, wad, and powder WEIGHT.
Weigh the entire round and see the difference

There ya go. Assuming equal velocities.

 

[ArmedBear]

Dr. THW-

I have had the forcing cones lengthened on a 20 Gauge field O/U and I could tell the difference. Spreading out the impulse does matter.

However, the shot column doesn't move much, so I don't think that will have much effect, except at points where it is compressed. Still, if a slug had to be compressed at the forcing cone, I think it would blow up the gun, so I'm going to guess that the wad takes up that space, or a soft gas seal at the base of the slug does. Either a plastic wad or a soft gas seal is compressible, just like shot.

 

[Boats]

F=ma

In this case, the force is working against your shoulder in accordance with Newton's Third Law of Motion:

For every action there is an equal and opposite reaction.

Since the mass of a typical lead slug and the nine lead pellets #00 Buck is fairly comparable, the culprit in increased felt recoil has to be that the slug round accelerates harder due to its more efficient utilization of the propellant.

 

[sarduy]

it's like the rain, you can stand in the ran all day long, but if all that water turn it into a solid block of ice and let it fall on you... that's a different story.

same goes for falling snow and an avalanche...

the weight is the same... but the mass is different.

 

[NoAlibi]

Fluid dynamics begins well before the forcing cone. It starts in the chamber as the shot at the bottom of the shot column accelerates into the rest of the column. The forcing cone and to a lesser extent the choke add additional impulses. These impulses are mitigated by fluid dynamics that is not found in the reaction of the solid projectile.

No one rejects the formula that recoil is the product of the total ejecta and velocity and the laws of physics states that you will get every iota of it. But the felt recoil can be influenced by semiautomatic actions, recoil devices, lengths of forcing cones and choke constrictions or lack thereof.