Mini-14 vs. AR-15 Accuracy

On a whim, I decided to shoot my Mini-14 and AR together at the bench to see which one was more accurate. Conventional wisdom says ARs are unusually accurate for semi-auto rifles, and that Mini-14s' optimal target is the side of a barn. From the inside.

This didn't jive with my experiences: The Mini never had any trouble hitting the target that couldn't be ascribed to the shooter, and the AR never showed any noticeable advantage in this regard. I'd read both that the new 580-series Mini-14s (introduced in 2005)have done away with most of the design's renowned inaccuracy. On the AR side of things, I've always suspected that the design's gilt-edged accuracy is most pronounced in upper-tier or target models, and the more basic (read: affordable) carbines are not significantly more accurate than competing designs.

But this was all casual anecdote and supposition. To know for sure required testing the accuracy of the AR against the Mini-14. Since I had limited ammo, there'd only be a couple data points to compare one against the other, and the results wouldn't indicate anything about Minis or ARs as a class--just the two instances I owned.

Mini-14, in case there's some confusion.

The Mini-14 is the Tactical model with a 16.25" barrel and 1:9 twist rifling. It's fitted with an Ultimak forward scope mount which clamps to the barrel. The gas system has a reduced-diameter gas bushing to reduce the distance cases are thrown. (It does not succeed at this task.) The trigger group was worked on by Bill Springfield to make the pull crisper without reducing its weight below 5 pounds.

AR-15, in case confusion persists.

The AR is home-built on an Aero Precision lower completed with a DPSM parts kit. The mil-spec buffer tube is fitted with a SOPMOD stock and uses an H2 buffer. The upper, bolt, and bolt carrier are by RRA and the barrel has a 1:7 twist.

Because the barrels have different twist rates, and one might favor a certain bullet weight over the other, I used 55-grain FMJ boat-tailed bullets and 62-grain SS109 bullets, both my PMC.

To remove myself from the equation as much as possible, I shot off bags. To remove any advantage or disadvantage introduced by optics, both rifles were shot using irons. The Mini-14 got a slight advantage here because it has a narrower front sight; however, the AR's small rear aperture is smaller than the Mini's. Targets were shot at 50 yards so that I could actually see them well enough to get a modicum of precision. Each target got five rounds.

I'm not a spectacular shot with rifles, so I expected that my own inherent inaccuracy would mask most of the accuracy advantage of the AR-15 over the Mini-14. That plus the better trigger and narrower front sight on the Mini would produce groups within 25% of the size of the AR, which would at least show that Mini-14s aren't THAT horrible when it comes to accuracy, and that entry-level ARs aren't that much better.

The results were nothing like that.