Without any problem? Dunno if I'd say that ...
I've asked this same question during different S&W armorer classes and received pretty much the same answer. S&W realizes that some of their LE customers are going to use higher pressure ammunition in their service weapons (+P/+P+ in 9mm & +P in .45 ACP). S&W tells its LE customers to shoot whatever is issued and recommends periodic inspection for signs of wear, damage or an out-of-spec condition which would require parts replacement. They stress the importance of properly maintaining pistols which are going to be used for dedicated defensive/service usage.
The first time I asked this question in a class the armorer instructor (long time production assembler) said that higher pressure ammunition can certainly accelerate normal wear and tear. Also, that S&W had noted the potential for some conditions to occur when higher pressure ammunition was consistently used.
One example was the potential for the slide stop lever to acquire an angle deviating from the normal 90 degree angle between the lever body and the pin.
We were told that recoil forces can do strange things. S&W had seen the slide stop levers sometimes acquire an angle either greater or lesser than the original factory angle. In other words, the lever body might bend either outward, away from the frame (at the rear), or inward, rubbing against the frame (also at the rear). Both conditions might eventually lend themselves to potential functioning issues.
If the lever acquired an outward bend it might eventually cause the lever's plunger to shift outside the side plate's front angled plate, interfering with normal operation of the lever. the lever's inward extension might not reach far enough inward to reliably engage the follower's shelf so the slide would lock open on an empty magazines, either.
If the lever acquired an inward bend it might potentially interfere with normal functioning at some point because of the back of the lever rubbing too much against the frame, creating too much drag, or the lever's inward extension might hit against the noses of the cartridges and be bumped upward when rounds remained in the magazine.
Recoil (and magazine) springs would probably have to be replaced sooner, too. More pounding and increased slide velocities by the higher pressure ammunition.
I've actually seen a couple of slide stop levers in alloy 9mm's acquire both inward and outward deflections after a lot of +P/+P+ usage over time. I've seen others that didn't, but a couple or so which did. Well, that's why we're told it's recommended to periodically inspect and look, isn't it?
The armorer's class used to teach armorers how to use a Babbitt bar to safely restore the original angle to slide stop levers, but they stopped doing that and now just tell armorers to replace the entire slide stop assembly if it changes from the original angle (or in any way from any other factory original spec). Too much to teach and learn in a short 3-day class. Easier to simply replace the entire assembly (it does contain a plunger, spring and roll pin, you know, making it an 'assembly').
Also, something to bear in mind is that all +P & +P+ ammunition may not be 'the same'. I stick with some offerings from the major makers that have gained experience with producing ammunition for LE agencies.
Higher pressure ammunition is just that ... higher pressure ammunition. How the ammunition maker arrives at increasing the pressure to fall within the +P designation may not be the same for each maker. Higher pressure does not necessarily mean significantly higher velocity, either, or increased 'ballistic performance', for that matter. There may be a trade-off in wear & tear on the shooter/pistol, compared to realistic 'ballistic performance' on target, that is not acceptable to someone or some agency upon occasion.
+P+? That means it's higher than +P ... but how much higher?
There was a time when LE agencies were asked to sign a waiver when they ordered higher pressure ammunition.
Increased inspection and maintenance issues which may be associated with the use of higher pressure ammunition may not be considered practical by some folks.
Now, I've used +P and some +P+ (Winchester 127gr RA9TA & a Remington LE 115gr JHP) in my CS9 (and some other 9mm pistols) without visible accelerated wear and tear. I also carefully inspect and maintain my guns.
In the little CS9 I've decided I'm more comfortable replacing the recoil spring somewhere around the 800 - 1,200 point because I occasionally shoot a box or two of +P+ loads. The factory recommendation for recoil spring replacement is much longer than that. I like to err on the conservative side of safety. Springs are pretty inexpensive and I order several at a time to save shipping costs. (I do the same thing in reqard to my CS45.)
FWIW, the present 9mm ammunition my agency issues for duty/training use is a 124gr +P load, and as long as that's the case I'll be using it for my training, including in my CS9. (It used to be one of a couple of standard pressure 147gr loads.)
You know, I used to carry different standard pressure loads in my short-barreled 9mm pistols without losing any sleep at night, including some 147gr & 124gr HP's. I'd do so again if that's what we were issuing or authorizing again.
There's some good quality, improved bullet designs on the current market nowadays.
Just my thoughts.
