1) Velocity and terminal effects
In the case of the AR15 we have peak
efficient use of the .223 / 5.56×45 is somewhere around 18 inches of
barrel. A rifle of any platform, in my definition, would take advantage of the chosen cartridge to the point of peak efficiency. A carbine does not stretch the cartridge to its limit but allows a more compact platform as the tradeoff. For the 5.56×45 we have a velocity “grey area”. A few 100 FPS isn’t a whole lot when comparing a 16 inch carbine to a 20 inch rifle, but keep going shorter and we really dig away at what makes the 5.56×45 special. The round shoots so flat at typical self defense ranges it may as well be a laser to 200 yards.
“What about fragmentation? It’s a moot point if your using good ammo isn’t it?”
I know many people say that they use high grain match ammo (insert brand here) which fragments out to forever in their 10 inch carbine. I don’t doubt the quality of that stuff and I wish I had the money to shoot stuff like that all the time, I really do… but the fact is shooting the same thing for practice and self defense appeals to me, and ergo I want one type of ammo for all my shooting. 55 grain M193 is (was) affordable, is still flat shooting, and I can get close to it with my reloads.
It just so happens that a
rifle length AR15 is one of the most reliable members of the AR15
family. Keep this in mind. I did have my first malfunctions with my primary rifle last week at a match, but this needs to chalked up to “don’t change anything before the match.” I brought untested magazines and they were my downfall. However the Rifle platform has been good to me. Ever see A2 guys asking about buffer systems or H1, H2, H3 buffers? Ever see a 20 inch guy talking about tuning their rifle? O-rings under the extractor? Carbines are reliable, but they have had much development here to ensure that. The AR15 rifle length platforms should give an individual longer service life between parts repair due to it being a soft shooting weapon with a less aggressive gas system.
3) Sight radius
Moot if your an optics only guy, but important to me since I use both irons and a RDS together. Simply put the extra distance between the front and rear sight allows you to see and correct the sight picture easier than if you had a short sight radius. It doesn’t make the rifle more accurate, it makes you more accurate with the rifle.
4) The little details
A few final thoughts on the rifle. The extra weight will be a bonus to the shooter since it will keep the sight picture a bit steadier under fire and at rest. I am eager to add a battle comp to see just how little recoil my rifle could have. Furthermore the extra weight will help diminish felt recoil. A little extra weight here is of benefit since the small movements of fine motor muscles and other muscle groups should impact my sight picture a bit less due to the weight.
The AR15 as the Rifleman’s weapon
I hear you coming you know… you M14 guys, I heard you around the corner. I knew you were there. “The right tool for the job of a Rifleman and distance shooting is .308 launched from a M1A.” Thanks Fred. I know the .308 hits harder, is less affected by the wind, is as common as dirt. All yes, yes, and yes. My goal here is to help and encourage others to become Rifleman. We have so many new shooters out there with rifles set up dopey and topped off with Wal-Mart China optics. In order to reach out to them I need to speak their language, and most likely their language is AR15. As cool as it would be to have the M1A, AR10, or (insert .308 here) as the most popular rifle in America… it’s not happening. If we want to be a nation of Rifleman then we need to be able to teach others how to shoot on a widespread and well loved platform.
As a final thought I don’t want to start a war here, but I appreciate the rifle for what I am doing. I appreciate the error it removes from my shooting with the flatter trajectory, longer sight radius, and slight increase in weight over carbines. As my aim is to shoot at longer distances and help others towards the same goal, the rifle is the right tool for the job. Home defense or getting out of a car often? Get a Carbine. Shooting longer ranges? The job of shooting accurately at a distance will best be done with a rifle and new shooters will most likely have an AR15.