Fish,
I have a Cooper 92 in .280 AI, and it's been a challenging gun. Like Hoyt said, it's great to carry, and probably not the ideal gun for really tight groups out past 400-500 yards due to the weight of the rifle. If you have any flaws in your shooting technique, this gun will expose them as the slightest inconsistencies will have great impact in a gun this light. It has an excellent trigger, and I have a Leupold 4.5-14x44 VX3 on mine currently. My rifle has been very difficult to get sub-MOA, let alone anywhere close to the .5 MOA Cooper guarantees. The lack of factory ammo in .280 AI is the first limiter, but I've been reloading for a decade and have several guns from other makers that I've worked to sub .5 MOA rifles.
When I called Cooper to ask questions about the target that came with my rifle (which is one ragged hole, 3 shot group supposedly), they were very forthcoming with the data they had worked up for .280 AI. I was warned that due to the light nature of this rifle, the action screws can come loose over time, so make sure they don't move when you are shooting. Also, I was told that the .280 AI they have worked with in the 92's seems to prefer lighter for caliber bullets, which is odd considering the barrel is a 1-9" twist, perfect for the 150-160 grain 7mm bullets. The most accurate load data they had was using RL19, 52 grains with a 139gr Hornady GMX, which I found to be useless and frankly absurd for a .280 AI, far below any usable threshold for this caliber in any practical situation (performance much closer to a 7x57 Mauser or a slow .284 Winchester). This cartridge should be using 58-63 grains of RL19 for a 140gr bullet,depending on your rifle, and 52gr leaves behind hundreds of ft/sec of performance for a .280 AI.
I was hoping the data they came up with would produce a load much closer to the actual "hunting" performance of the caliber, but it seems they were focused soley on accuracy. I'm currently working through my 8th, 9th, and 10th different load ladder with this gun, and am nearing the point of concern where I am going to send it back to Cooper for evaluation. Nosler Trophy Grade 140gr Accubond ammo isn't consistent enough to hit a 24" square plate at 400 with two shots in this gun currently, and is somewhere in the neighborhood of 1.8-2 MOA at 100yds, very disappointing for a gun and ammo that are both carrying sterling accuracy reputations.
I've spoken to several other people who have 92's (7mm Rem, 6.5-284, .300 Win) and have heard promising things from many of them. I'm curious if mine is an outlier, but several other guys have been able to find very accurate and functioning handloads for their 92's so I'll keep working for now.