Actually, its both a LOCK and a RELEASE. When it locks the slide back after the last round, it serves one purpose. When you push that little lever DOWN to let the slide slam forward, it becomes a RELEASE!

Different gun makers call that little lever different things, but a single name doesn't properly describe it's dual function. (Interestingly enough, H&K in the manual for the Model 23, calls the lever a "slide release." But what do they know? Beretta calls it a "slide catch," and recommends pressing it to close the slide and chamber the first round of a new mag. (page 14 of the Beretta 92 series manual.)

Some gun makers offer EXTENDED SLIDE LOCKS or EXTENDED SLIDE RELEASES. Why would they offers an EXTENDED anything, if it was only meant to be used as a SLIDE STOP and you are supposed to ONLY use the slingshot method to release the slide?

If you shoot in any of the gun-game venues you won't see many folks use the slingshot release method. You'll see the slide "stop" pressed, or the hand-over method used -- especially by those shooting S&W semi-autos.

Do a quick Google search on "Extended Slide Release and see how many HITS you get. Wilson Combat (for 1911s) and after-market vendors for Glock weapons offer all sorts of Extended Slide Releases. You'll even find after-market parts for the S&W Shield. I've also had extended releases installed on Tanfoglio-made CZ pattern guns, and they worked in my CZs, too. Handy things. The Glock 34 comes with an extended slide stop lever as standard equipment -- but, as I asked above, why is it extended if the sling-shot release is the best release method?

SIG, like Beretta, calls their lever a "slide catch" on most of their P-series guns. For the P226 X-5, when unloading, on page 8, it tells you to "actuate slide catch lever. The slide... flys forward." They don't say press on the slide catch and use the slingshot method.

As to your other point about premature wear: can you cite some examples of guns that have become disabled or badly worn by using the slide lock to release the slide? I've seen slide stop broken, but never worn out -- and only in certain types of guns, at that.

I would note, too, that last I heard (as conveyed to me by a civilian trainer who works with Special Ops troops at Fort Bragg), the DoD now trains troops to use the slide "lock/release" to release the slide. Why? Because troops were having so many failures to go into battery under combat conditions when the "slingshot" method was used. (A lot of the troops had to wear gloves because of the cold temperatures or rocky environments, and the gloves made clean releases more difficult.) The DoD apparently thought the change was appropriate for all environments. Then, too, the alternative "hand-over" method used by many shooters doesn't always work with the Beretta, as some larger hands will decock that weapon when that method is used.