Yes it is a OLD thread, but rather than start a new one and have everyone repeat what has been said I thought it best to zombie this one a bit.
The 700 vs the 721/722 actually a good topic.
Which one is stronger? Better built? More accurate?
The answer is subjective, they are on par IMO. Personally I think it's a wash. I've owned and operated all three differing models, which I do prefer? The older 721/722 only because they predate the 700. Couple that with the fact they had a shorter run time (1948-1962). The 700 from 1962 to present.
Otherwise I view them pretty much equal when looking for a new donor action or rifle. Some will tout the Townsend Wheeling's testing of the 721/722 for strength at Springfield Armory. But it's not a fair comparison as the 700 wasn't available then, and the Armory was pretty much shutdown by the 700's introduction.
Bolt bodies, the 721/722 will accept the 700 bolt body, but not vice versa. Thanks to the left bolt lug cutout in the 700 series. Could the 721/722 bolt body be modified? yes but by the time one pays a machinist the 700 bolt body is way less in cost even though I cringe at the price many demand for them.
Both was machined (drilled and tapped) for receiver sights, except the later productions of the 700. (some reason post 1984 comes to mind but not sure the exact date in the 1980's, Although the exception is the M24 SWS series).
Magazines are different, the 721/722 I have are attached via a screw to the bottom of the action, latter 700's did not use the same method.
The 721/722 has a stripper clip cut out vs the latter models of the 700. Which when scoped is useless but still has that capability if one simply uses iron sights.
Extractor is another issue in the interchangeability, which can be fixed in either model with a M16 style or Sako extractor installed when parts are just not available.
Scope bases and mounts are identical the 721 correlates to the 700 Long action, The 722 to the 700 short action.
When restocking say a 721 or 722 action to a 700 stock yes some refitting in the rear tang is involved as the shape is different. The 700 has a trigger safety cutout vs the 722/721 sitting to the outside. The triggers don't interchange (unless the safety is removed or a 700 style trigger without safety is used). Lest we forget the Bolt handle when stocking the 721/722 uses a straight design vs the 700's swept design. The solution is either bend the handle OR simply refit a 700 handle to match the stock. The other method glue in wood and recut the bolt handle cut out. Which works whether it's a 721/722 stock to a 700 or vice versa. The other issue is the 700 ADL/ BDL stocks in the magazine cut out. The 721/722 did not use a blind magazine. So many simply Tig the blind mag assembly to the 721/722 action for the ADL series of stocks. To get the bottom metal to work with the BDL requires a bit of work.
( the 721/722 "usually" has one more pass through action screw in front of the trigger guard than the 700 in latter production)
Cost? hmm sometimes the 721/722 series does actually cost more when looking. Sometimes it's reversed, factory caliber is the factor I've seen. It's usually the 722 that most times demands the higher price point (.222, .257 Roberts, and 300 Savage chambering). The 721 in the normal bolt face of .473 usually will be less than a used 700 Long action, which if your intent is to do a wildcat, or simply spent less for say a .270 or 30-06 maybe a viable option. Which most detest the long action for some reason, which keeps the price at bay for the 721.
So Gentlemen what have I simply forgotten to include in the conversation?
Regards
Mike