I don't know what twist my mini-14 has but it shoots a lot straighter with heavier ammo. I can't remember the exact weight but I bought a box each of several bullet weights and types, (FMJ, soft-tip, hollowpoint) and while bullet type had no effect on accuracy, the heaviest rounds were measurably more accurate than any of the lighter ones. The spread of the lightest rounds was nearly double that of the heaviest, at 100 yds.
I never target shoot my mini-14 past 100 yards, and I put a durable fixed magnification scope on it (3x or 5x, can't remember which) to try to make the scope last longer since these things beat up scopes. If the scope ever breaks I'll probably put a low magnification red-dot sight on it, since I sort of fell in love with the red dot sights after completing a combat arms course with an M-4 with a red dot sight. The M-4 with the red dot sights are really nice to shoot, and my mini-14 would probably point almost as easily as the M-4 if it had a similar sight.
BTW that shooting course was awesome, part of my air advisor training prior to deploying as a military advisor in Iraq. It was taught by a bunch of ex-SEAL types, special forces, SWAT members, etc. We only used targets as something to point the weapon at, and the training focused entirely on target presentation and getting the weapon into use quickly and accurately without blowing off our own foot or shooting the guy next to us. We did stuff that would have caused heart attacks and seizures on normal USAF ranges
We did stuff like standing in a normal shooting line facing AWAY from the target, then turning and firing 3 shots with the M-4, lowering it to sling carry and switching to our secondary weapon (M-9 pistol), and firing 2 more shots with the secondary weapon. Practiced the difference between reloading after emptying a magazine (let it fall) vs. swapping out a partially full mag (stuff it in your shirt or in a pocket during the reload), clearing the weapon in a hurry, and switching between primary and secondary weapon. We did off-hand shooting, plus a bunch of other easy techniques that focused on getting reasonably well aimed rounds downrange in a hurry. We didn't look at our targets when we were done, because it didn't matter. Plus we shot well over 100 rounds each from a variety of positions, so the targets wouldn't have told us much of anything.
Fun stuff - Fire 3 rounds standing, drop to a crouch and fire 3 more which emptied the magazine, reload, drop to prone and fire 3 more, then simulating out of ammo or malfunction, switch to secondary weapon and fire a couple of rounds from the M-9. Good times.
