The 721 is pretty close to a 700, the biggest difference I'm aware of is the extractor ring in the bolt face. Rather than having an extractor milled into the bolt face, the 721 has a ring of rolled/stamped metal that clips into the inside of the bolt face.
This ring is relatively weak compared to a 700 and occasionally breaks.
I thought all the original 721's came in blued steel.
the one i have was made in 1956 and it does have a stainless steel barrel i had a friend that is really into guns check it out he said it is stainless he said it is probably a rare one the letters on the barrel say it was made in 1956
Here is a tip that was passed along to me - and I have not tried it yet - but it looks (and smells) like it will work fine! The gentleman that gave it to me regards it as his secret weapon and he is a VERY successful hunter.
Get a fresh tarsal gland off of a decent buck - I think the ranker, the better. Taking them off of bucks that are hot in the rut seem to be the best because that is when the glands are the darkest and have the most "male buck" scent...
Take that gland and put it in a good,...