For the most part, I'd say yes +P is worth the extra blast and recoil in a .38 Special. I say this because there are precious few good standard pressure .38 Special defense loadings. About the only two standard pressure .38 Spl hollowpoints that I'd trust to both penetrate adequately and expand reliably, especially from a snub, are Hornady 110gr Critical Defense and Buffalo Bore 158gr LSWCHP, 125gr JHP, or 110gr Barnes XPB loadings (which will probably have recoil and blast about like everyone else's +P). Federal's 125gr NyClad is probably better than most other standard pressure .38 Spl hollowpoints, but it's penetration is still a bit on the shallow side for my taste.
Just about every other standard pressure .38 Spl hollowpoint loading I can think of suffers from one of two problems: either the velocity is too low to ensure reliable expansion or the bullet is too light and fragile to yield adequate penetration. So long as the revolver can handle it, my reccomendations for .38 Spl snubby loads are Speer's excellent 135gr Short Barrel Gold Dot or Remington's equally excellent 158gr LSWCHP both of which are +P loadings.
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