It seems like it was yesterday that I got my first AR15. It was one of the transitional rifles that Colt produced called the AR15 A2 Sporter II. I say it was a "transitional rifle" because it was the civilian version of the then new M16A2 adopted by the Marines and it had a mix of A1 and A2 features.
The Marines requested the A2 updates to the M161 which were intended to increase the accuracy potential of the rifle in the hands of Marine riflemen. Most of these changes centered around improved "combat adjustable" sights, a heavier barrel and a slightly longer stock.
I did a video about my Colt AR15 A2 Sporter II several years ago. This video goes into more detail about the rifle and my history with it.
When I had gotten my AR15 A2 Sporter II, the sights were a mix of A1 and A2 features. The rear sight had the older M16A1 non-combat adjustable dual aperture and the updated front sight with the square post vs. the round post found on the earlier A1 rifles.
This is the rifle I learned how to shoot before enlisting in the Marines. I spent countless hours shooting the Colt from the standing, kneeling, sitting and prone positions. The time I spent with the AR15 A2 Sporter II certainly gave me a leg-up in bootcamp and likely assisted me in achieving the Company High Shooter award.
Above: Me (standing - left) receiving the Company High Shooter award at MCRD San Diego
In the 1980's we had sights like the Armson OEG (Occluded Eye Gunsight) that were predecessors to electronic red dot sights. We also had the Colt 3x and 4x magnified optics that attached to the carrying handle of AR15's, but iron sights still ruled the day on firing ranges around the nation and in the U.S. military.
In 1997 the M16A2 with its fixed "carrying handle" (aka "Army handle") was replaced by the M16A4. The key feature of the A4 was the removal of the carrying handle and the inclusion of a 1913 rail across the top of the receiver. This would facilitate the use of magnified optics like the ACOG or red dot sights like the M68 (Aimpoint CompM2) that was adopted in 2000 along with other force multipliers.
This is why I call the M16A2 America's last rifleman's rifle.
Above: FN M16A4 clone on top with Trijicon RCO optic, Colt AR15A2 on the bottom
While the use of optics like the ACOG still requires the shooter to master fundamental skills such as stance, proper use of the sling, sight picture, breathing, trigger control, etc. it removes one of the more difficult aspects of marksmanship for many to master - sight alignment and sight picture as it relates to irons.
Optics like the ACOG, which enjoys widespread use in the U.S. military, clearly increases hit probability for the Soldier or Marine rifleman. They allow a better view of the target, a simple to use chevron to place on the intended point of impact, a bullet drop compensated reticle, illumination for low light situations, etc. It is far easier to teach a recruit how to use an ACOG/RCO than it is to teach them to use iron sights. Such force multipliers vastly improve hit probability across the board.
I'm old school. While I would definitely want all the modern do-dads and gizmo's on a fighting rifle should I find myself in a gunfight (I was a peace time Marine by the way), on a regular day at the range I much prefer to shoot irons. Why? Because the discipline that's required to use them effectively, especially at range. With an ACOG scoring 500 yard hits takes only a modest effort on my part. I can be quite sloppy in how I shoot and still manage to score hits with an ACOG equipped rifle.
Above: Looking over the irons of my AR15A2 on my rifle range
Even a red dot sight (RDS) significantly increases hit probability for most shooters vs. iron sights. The RDS removes the requirement for a proper check weld and the precise alignment of the front and rear sight while applying the other fundamentals of marksmanship while engaging targets at extended range.
Once you start shooting at 500 yards with iron sights using an AR15 type rifle you must apply all the fundamentals of marksmanship if you want to score hits, and honestly, a rapidly decreasing number of people have the skills to do this today based on what I've seen at public ranges. It's a skill that is slowly being lost to time as new shooters almost always start off with modern optics vs. learning the basics of marksmanship using iron sights.
When the A4 version of the AR15/M16 hit, that was the beginning of the end of widespread use of irons sights in the AR15 community.
The A2 was the last of the AR15's to be a classic marksman rifle. This is one of the reasons I love the AR15A2 so much and why I find myself shooting it regularly.
When I'm having a bad day, I grab one of my A2's like the Colt pictured above and head to the hill where I can set the worlds problems aside for a while as I focus intently on hitting a target so far away that it looks like a tiny little speck of white that's easy to lose sight of if you don't pay close attention. As long as I read my wind right and align that front post perfectly in the rear aperture, then apply just the right amount of Kentucky windage, I'll be rewarded with a distant sound of a 55gr bullet smacking that 8" steel plate.
If you don't have a rifle with iron sights, I suggest getting one or at least buying a good set of "back up" sights and learn to use them. I think you'll find it challenging to master them but when you do, you'll also find it to be quite rewarding.
Long live the AR15A2/M16A2.