Would you guys recommend a 1lb increase over the standard spring? I'm just looking to spare my autos from unnecessary wear regarding battering of the frame. And what about recoil buffers?

No, I would not, unless all you shoot is hotter loaded ammo.
14# is about right for those Smith 9`s.
I have one 559 that will not function with 1000 fps loads but runs beautifully with 124`s at at least 1150fps. In this gun I was tempted to try a 12# recoil spring to see if it would increase reliability with the
loadings that run in the lower velocity range but it shoots so well with the warmer ammo, I left the 14# spring in place.
Unless you are experiencing FTE`s remember, if it aint broke, dont fix it.
Jim

Well, it depends...

First of all, Buffers? Never. Especially not for any arm intended for serious purpose. A buffer takes up space. Nearly an eighth of an inch or thereabouts and will short stroke your slide an equal amount which may cause feed and/or ejection faults.

Now about recoil springs...

First of all, realize that extra power springs throw the slide back into battery with more force & speed than the factory rated spring does. This means you'll be beating the snot out of the mating slide/barrel locking lugs, stop pin and camming lug.

Spring your guns according to how they behave with the loads your shooting. Pay close attention to the recoil impulse. Excessive muzzle flip & sharp rap in the hand would lead me to install a firmer spring. Also observe closely how & where your brass ejects. Violent ejection launching your brass into the neighboring county would indicate a weak spring which goes hand in hand with the aforementioned excessive muzzle flip & felt recoil. Conversely if the brass is trickling out and landing at your feet, there's too much spring in the gun.

I like my empties to land about 4-6 feet away at around 4 o'clock and spring my guns accordingly for the loads I shoot.

Do not use extra power recoil springs as prophylaxis against possible battering. Extra power springs and reduced power for that matter are intended for addressing issued with function & reliability applied to certain loads. ie. light spring for target loads, standard weight for standard loads, +p or +p+ loads may merit an extra power spring.

Newly acquired guns with unknown history/round count automatically get a fresh S&W factory weight spring. Then based on some range time observing how the gun behaves, I'll determine whether any change in spring rate is merited.

A fresh recoil spring is cheap insurance against undue or premature wear on a semi. I got bags of springs and change mine regularly as conditions or round count indicate.

One more thing...

Don't discount the mainspring or hammer spring. When firing this spring does much more to delay unlocking and throttle initial slide velocity than the recoil spring does. Recoil springs would be more appropriately named return to battery spring as that is their primary job, throwing the slide forward into battery with a fresh round. Mainsprings can be tuned as well and may be had in different weights.

In the end, keep good spring in your guns. And stop worrying about possible battering. Start with the factory S&W springs specified for your gun. Replace then periodically. The factory standard is every 5years or 5000 rounds as I recall. I tend to be a bit more liberal with replacing my springs especially in my carry guns. Cheap insurance to make sure they work when needed and last a good looong time.

Cheers
Bill

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Because they don't make a .46

Bill,

Based on your main spring comment, do you recommend the same type of routine replacement as you do for recoil (return to battery) springs?

I have a bag of recoil springs for my compact 9mm 3rd Gens, but have never thought about buying main springs.

You comment about mile long brass ejection makes me think that my little Bersa might need a different spring. If I can find one. I tosses brass 15 or more feet and is pretty snappy in the recoil department. Of course .380 is a snappy round and fixed barrel semi autos seem to have higher felt recoil.

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Can open, worms everywhere.

No I just replace the mainspring when I get 'em.

A new (to me) gun with unknown history & round county typically gets every single spring replaced with new. I'll replace the mainspring with a standard weight 20# when I go through the gun in detail then I'll pretty much forget about it. I'd only mess with it again if I noted some signs of early unlocking on the brass (ie. case bulges)which could not be attributed to something else. In which case I could either bump up the recoil spring to one exerting more force when in battery (will likely alter ejection pattern) or... increase the weight of the mainspring (will increase DA trigger weight).

There's a delicate balancing act going on here between the slide's mass, the recoil spring, mainspring and the load power.
For the most part the engineers at S&W had this all figured out. In other cases not so much (4516-1 for example was undersprung IMO).

On a used gun, you never know if the mainspring has been changed to something other than spec or is just plain worn out. On older guns like the OP's first & second gens those mainsprings might just be tired. Can't hurt to stick a new one in there and not worry about it for another 40 or 50 years

Cheers
Bill

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Because they don't make a .46

Thank you sir for words of wisdom! Those spring service paks from wolf are sounding like a great idea for only $15 each.

d.b.d.2005. thanks for asking them same question I was going to ask... I have alloy frame 915 and after looking at the Wolff springs on Midway they say factory is 14lbs. and I was wondering too if maybe 16lbs might be a good idea.. but after reading this post i'll stock to 14lb.
my 915 looks like new so I am thinking not shot a lot but not knowing the age or round count on the recoil spring $8.00 is cheap to change and not hurt a guns frame.