Re: Dry firing
99.9999% of the things on this planet are perishable...in some form or another. I this case, we are comparing that of a firearm made of steel and synthetics (for the sake of argument) versus your skills. Human skills will spoil quicker than a month-old eggs left in the hot sun. Your rifle will degrade about as fast as the styrofoam the eggs came in.
To say that dry firing can't cause wear and tear to a firearm isn't exactly true. Springs are used, surfaces rub....thus wear and breakage is theoretically possible. However, this is incidental compared the stress that is put on your gun during live fire.
I can not imagine any breakage that would occur during dry-fire that would not occur during live fire. The only exception being with that of a rimfire. In fact, dry-firing tends to increase one's quality time with their firearms so you should be more in tune to when something doesn't "feel right", and can be investigated before becoming an issue.
The cost/benefit breakdown has proven time and time again that the muscle memory and familiarity accrued during PROPER* dry fire training is worth the effort.
*Proper dry firing means training as you should under normal firing conditions including (but not limited to):
- muzzle and trigger discipline
- over emphasis on fundamentals
- proper fighting mindset
Sitting in the lazyboy, gun in hand and clickin' off at the TV every time a tampon ad comes on the screen isn't going to offer much help.