I posted in a thread in the reloading section some chronographed velocities of Super .38+P. Overall it is pretty anemic at 1142 fps. That was Winchester Super X. I guess I should ask what you are shooting it in. Any Government model pistol can handle anything from the factory. I know some Cor-bon and Buffalo Bore stuff can get pretty hot so maybe a steady diet of that isn't a good idea. What are your intentions for it? Fun or protection? Mild stuff for fun, and +P for protection.
The Super SHOULD be a 130 @ 1300. It used to be so. In the last 10 years or so the ammo companies have quietly reduced the load to around 1100 which nearly duplicates the old 38 ACP load. I suspect this was done on advice of counsel worrying about lawsuits from some nimrod firing Supers in his old 38 Auto pistol. I noticed this when Super cases stopped being exclusively nickel. Used to be 38 ACP was in brass and Super in nickel for quick ID. Now Super comes in brass as there is no need to tell them apart. The Super is now a caliber that requires loading your own. If restricted to factory ammo you might as well have a 9mm.
The loads I Chrony-ed were closer to 1200 fps, but I do agree that the older stuff was rated @ 1300 fps, but my yellow box of SuperX 38 Super Automatic has 1280.
When Winchester introduced the 125 Silver Tip HP it was also rated @ 1300.
The .38 Super Auto still trumps the 9mm with standard factory loads IMO. Most 9mm these days are a 115 gr load whereas the Super is 130.
I've been told, repeatedly on forums, that modern .38 Super Ammo is marked +P so people won't load it in a pistol chambered in .38 Auto. I agree though, my older Winchester Silvertip .38 Super seems hotter then the new stuff.
I did get lucky; I have traded ammo and some cash for almost 2,000 rounds of Super ammo, including 600 rounds of silvertips; two different deals from the same gun website, Michigan Gun Owner's.org. (migunowners.org)
I recently bought several cases of Federal 38 Super+P ammo and just took a Maryland State Police Handgun course. The instructor stated that if the gun
isn't stamped +P,, you shouldn't shoot +p ammo. I guess it's a good general rule to follow,,, but was hoping it didn't apply to my super 38's, I've been shooting
+P for years.
I use the same ammo for practice and carry when I can, both 38 super and 45 ball in my Colt Gov't 1911's.