TAO1nsn's usually come with the TA51 mount, but if you dont have it, I would get it and use it on the flat top. Its a little easier and they bullet drop compensated reticle will work better. You may notice a sligh, slight blur in the very bottom of the glass when you mount it to the flat top, but unless you are trying to see it, you probably never even notice it. Most everyone I know who mounts them this was is ever bothered by it in the least bit.

You can put it on the carry handle if you want, and its not too bad, but you will have to raise your cheek off the stock a little to use it. It will throw off the callibration of the reticle, but it probably wont be very much. Please use the thread titled "Big ACOG BDC Chart" or something like that. Its tacked to the top of this section and will have specific info on how mounting the optic like that will effect the BDC.

In all honesty, mount it the way thats most comfortable for you and work it. You'll be fine.