I can speak for the Gunsite 223/ 556 classes here.
The reality of life, absent any strong feelings of attachment for a particular gun/ brand etc, is that the AR family is what performs best in that environment.
In the years that i have been teaching those classes, i have never seen a Mini14 complete either course. We did have one lady come through to do a TV shot, and she brought 2 ranch rifles (our suggestion). They both were TU on thursday, and she finished the course w/ my M4.
We have had several Minis through the Chiefs of Police courses, but they are of short duration (2 days pistol, 2days carbine, 1 day SG).
Several of thos attending the CoP classes also brought M94 30-30's, and did well.
We have had several AK varients through. One exceptionally talented shooter brought an AK74 and he and the carbine did superbly, open sights and all.
Note that he was very good, and could perform speed reloads, shot to shot, in 3 seconds. He was a Park Ranger type, had exceptional eyesight, and terrific motor skills.
Those few bringing AK47 varients were generally behind the power curve due to poor weapon ergonomics.
Having spent 5 years in a military unit dedicated to Foreign Material Acquisition and Exploitation, i have seen and fired many rounds out of many varients. I am not as enamored with the gun as many here seem to me. Its vaunted reliability is slightly better then the AR, but at the cost of efficient weapons manipulation, 1/3 of the combat triad.
Note that the 223 class is basically an intro to the system, and we shoot from contact to 300/ 400 yds, depending on the class quality.
The 556 is more of a fighting class, and ranges run from contact through 100yds, with the majority at or under 25 yds.
The 7.62x51 out of any gun is an extremely poor choice for CQB (I note that many are confused as to what CQB actually is) due to overpenetration and muzzle blast issues.
However, though the 223 class (the name is a clue!) is designed for tha caliber gun, we have had several people go through with M14 varients.
As a rule, the ergonomics will put them behind the power curve.
That caliber is better suited for the 270- General Rifle Course.
Personally, i would love to see a wider variety of 556 caliber weapons come through, but that doesn't happen.
This is quite possibly because the AR is a ubiquitous system, and is proven over the years, while many others are of small production runs.
I am not prejuidiced for or against any system on face value.
I am just commenting on what i have seen at the School house.
So- bring out your blaster and put it through the class. It may be enlightening for all of us!
In short, he would have done fine with any weapon, proving the adage "It is the Indian, not the arrow".