If an old down bag seems heavy, could it be that it just needs to get cleaned? I could have sworn it weighed under 2.5 lbs. It currently weighs over 3 lbs.

If it hasn't been washed in a long time, washing wouldn't hurt.

I'd stick it in the dryer and alternate low and no heat settings. Wonder if it absorbed some moisture.

Dryer first--as Lori says, the problem may be moisture. Lowest possible heat--you don't want to melt the shell!

If that doesn't work, then launder the bag, following the instructions on the Western Mountaineering website. These instructions are good for any brand of down sleeping bag. Highlights--use a large capacity front-loading washer and a large capacity dryer with low heat; run the washer for a cycle with nothing in it first to remove detergent residue; use a washing product designed specifically for down, not laundry detergent; renew the DWR with a spray before drying; plan to spend most of a day on this project. Since you'll probably have to do this at a laundromat, take a good book with you (something long like War and Peace). If you have a relative with a large-capacity front-loading washer and dryer, time to pay a visit!

Thank you, Lori and OM, for both your responses! I was thinking about OM's thread about the successful cleaning of a bag when I put this up...and this bag REALLY needs to get cleaned so I think I will try that approach. If it weighs the same, at least it will be clean.

Agree that done right, it can't hurt and will likely as not produce a fluffy, "new" bag.

But a half-pound of dirt? Unlikely. I'd eyeball the scales.

Happy cleaning!