I would guess not, simply based on the price. Also, it looks to have a different bolt system from the 700. My guess is that aftermarket parts and accessories would be hard to come by. I'd like to hear more from someone who knows more though.
I've been waiting for feedback of how these shoot. According to the Remington marketing machine, they're the most accurate, reliable and modern firearm produced in the universe.
I found this video of the 783 (all in French). Can't understand a word but after the 7 minute mark, the shooting begins and you see actual grouping. He managed some fair groups at the end. [ame=http://www.youtube.com/watch?v=kx_tLDN2_hc]La carabine Remington 783 cal 270 Winchester - YouTube[/ame]
The store I work at stocks these. We were not impressed by the rifle initially. It appears to be a significant improvement over the 770 line and is definitely designed to compete with the Ruger American. Overall, the rifle uses a barrel nut system and acu-trigger clone and an injection molded plastic stock on the models I've handled.
Although the price would suggest it's a cheap rifle made to compete with others at the same price point, I don't see it that way. I refer to Remington's claims. Anything less is a raw deal. Based upon claims, does it meet or exceed your expectations? I pretty much expect a .725", or better, 5 shot group from every 783 sold (minus a 5% variance for manufacturing anomalies) w/Remington factory ammo.
[ame=http://www.youtube.com/watch?v=cHCf3Irvhik&feature=player_embedded]The Rock: The New Model 783 - YouTube[/ame]