As stated above using the horseshoe in a slide made for a fully enclosed bushing is a No No.

The fully enclosed bushing ( used on the Pre 39 , 39 no dash and Model 39-2's made until around 1973 or 74) captures the guide rod spring,
Notice in the pic the guide rod hole is large enough that rod and spring will pass through the front of the slide with the bushing removed (Basicly unnecessary since the 39 has a solid guide rod and does not break down like a 1911).
The early design bushing is thinner and since it retains the spring it also bears its full force during recoil.
More importantly if the bushing is bent or broken it can render the gun inoperative and therefore is a weaker design IMO.

The "Horseshoe" style (Top in pic) also has a new smaller guide rod "Hole" cut in the slide ,
The new design uses the thick metal of the slide to capture the guide rod spring at the muzzle and the horseshoe shape simply prevents the bushing from rotating left or right with the guide rod in place.


Interestingly the removable barrel bushing was eliminated in my 3rd gen compact 9 utilizing a fluted barrel system instead.



On a side note there are two other designs that S&W used that Im aware of,
The Model 52 bushing which screwed in with a spring loaded stopper making it adjustable


and the later Briley brass swivel bushing found on many Performance center autos.