Sticky bolt on rem 721

[repeat]

I own a rem 721 in 300 H&H.The shells stick in the chamber when shot even with minimum loaded shells.
Awhile back I sent the bolt to a gunsmith in Selah Washington.He fits a 700 extractor in the bolt,the same ones the military uses.The extraction problem may be fixed but the shells still stick in the chamber.The new extractor tears the case head off and extracts that but the shell still sticks.
I polished the chamber(thats what the gunsmith in Washington said to do) with Flitz for a little over an hour yesterday and it still sticks.I have accumulated about 7 hours of polishing the chamber and went through 2 tubes of Flitz polishing it but the problem continues.
I have been reloading since 1970 and have the bullet seated .022 off lands and grooves.When it don't stick I get my best groups at around an inch.
I reload for 7 other rifles and don't have that problem with any others.
Any advice?

 

[lefteyedom]

A dramatic solution would be to have the barrel removed cut off a couple of threads re-cut the chamber .
Does this rifle stick with factory loads? if not then I would look at your dies....
Good luck....

 

[repeat]

It sticks with factory ammo(68.00 per box) and reloads.
I plan on doing as suggested and have the barrel setback and rechambered.Thanks for all your help.