why does this load makes a difference to common LRN 158 gr. if it has no +P added?
The old LRN (Lead Round Nose) tended to penetrate well but didn't expand. In addition, the bullet profile seemed to push the tissue aside leaving small sub-caliber wound channels and not much bleeding. It was an impressively poor self-defense round.
The 38 Spl. 158 gr. LSWCHP (Lead Semi-WadCutter HollowPoint) has a few things going for it. It's a heavy bullet so penetration is good even if it expands. It's got a shouldered bullet profile that tends to cut a wound channel even if the bullet doesn't expand--so no sub-caliber "ice-pick" wounds and reasonable amounts of tissue damage. And the hollowpoint is made from exposed and relatively soft lead so it doesn't take much to get it to expand to cut an even larger wound channel.
Back before the highly engineered high-tech expanding ammo came along, it was a great low-tech solution to self-defense in .38spl. Still not a bad choice by any means, but you may be able to improve on its performance with some of the new premium stuff from the better companies.
Bill Jordan said it was the most powerful cartridge an average man could achieve any real proficiency with.
He's not the only gunwriter to voice that opinion.
From the July/August American Handgunner
From the .35s to the .40s – They Still Call ‘Em .38s!
By Mike Venturino
...Most people in the know about such things consider the .38 Special is the minimum revolver cartridge that should be used for home/self defense. And I know for certain it is about the largest cartridge non-enthusiast people can be taught to shoot with any degree of proficiency.
From the July/August 2004 American Handgunner
By John Taffin
I consider the ... Model 10, as one of the best choices, perhaps the best for that person looking for a “house gun,” whatever that is, or a revolver for concealed carry.
The .38 Special is the upper-limit of comfort and easy handling for many shooters, especially senior citizens, younger shooter, and women with small hands; ...