I am still in shock as to the lack of information about this subject and the wonderful results it produces.
We have been making and canning sausage for years. The old pressure canner has more hours on it than my Toyota.
We simply make the links in lengths appropriate to the size of jars we are using, (usually quarts) fill them tightly, add water to about 1" from the top of the jar and process as for meat chunks or strips. No need to precook them. (90 minutes @ 10#'s is the rule we use.)
The high temp and pressure not only cook them but seem to force flavour into the links. If canning traditional breakfast sausage, omit the sage and add prior to serving if desired. Almost any amount of sage will cause bitterness and ruin the jar.
The small amount of water does not dilute the taste at all. We have added raw red peppers, sun dried tomatoes, garlic and onions to various varieties of sausage and have never had a jar that didn't invite positive comment. We don't can for preservation as much as for flavour and convenience. Drain a jar of country sausage and put in a frypan with a tad of bacon fat.
Brown them up, remove the sausages and excess grease and add a couple of TBSP's of flour. Stir up the bits and add the remaining liquid. If that contains too much salt, add milk instead. Return sausages to the pan, heat through and serve with mashed potatoes and fresh or canned vegys.