For years I have had my own views and opinions on the M-16/M-4/AR-15 platform and the .223 Remington/5.56NATO rounds and have shot a fair number of different AR-15s.
I like the style of the weapon the look of the weapon and the ease of use.
Over the years I have seen how interchangeable the whole weapon system is and how a simple push of two pins can change the weapon from firing a .223 to a .50 BMG or a change of the bolt can make it fire a .22LR.
The AR platform can be configured to a good number of different calibers such as: .20 Practical, 22LR, 5.45×39, .223, 5.56NATO, 6.5mm Grendel, 6.8 SPC 7mm TCU, .300 Whisper, .300 Blackout, .338 Lapua, .40 S&W, 10mm, .45 ACP, .450 Bushmaster, .458 Socom,
.499 LWR, .50 Beowulf, .50 BMG, 7.62×39 just to name a few
The upper can be changed to make the weapon a shotgun, a belt-fed weapon, fire pistol rounds or just be reconfigured into a short pistol style weapon.
The versatility that the AR platform offers to the shooter is almost limitless and with more and more companies designing uppers and various other parts the next few years will make it limitless.