Heavy is subjective.
My Rem 700 LongRange in 7mm RM. weighs about 12.5 pounds with bipod and 4-16x50 Viper PST. I don't find it unduly heavy, particularly as it's primary intended use is as a long range target rifle, and a medium/large game rifle for the low rolling hills of central and eastern Washington state. It would be a bit long and heavy to hump trough the denser forests of the Cascade and Olympic mountains on the western side, though.
My AR carbine weighs in at about 10lbs with light and 1-4x24 PST in a 1 piece ADM Recon mount. I find it comfortable to carry for extended periods, and handy to use from 0 to about 400yds.
The reasons i find both of these rifles a dawdle to cart around are, 1. I work on cars for a living; i do a lot of lifting, pulling, prying, etc. And 2. They all get compared to my PTR-91F, which with bipod, 2.5-10x32 PST, and Magpul PRS stock, weighs in at a solid 16lbs with magazine. I like to joke that I'm just a belt-box short of a SAW lugging THAT thing around.
So, how light you need?