My first memories of canning were watching my mother fill an old pressure canner with corn we had recently culled from neighboring fields. Farmers local to us used to allow us to go in and harvest the leftovers after the combines had gone through. We could easily gather 10 or more bushels per field. Now honestly, my mother recycled jars, spending money annually on lids but rarely on rings or jars! Both Ball and Kerr jars made their appearance in our house over the years.
Over the years I have seen arguments about which are better jars, Ball or Kerr and I am certain there was a legitimate argument supporting one over the other at some point, however, these days everything tends to be owned by one company. Canning jars are no exception to this general rule of thumb, Jarden Home Brands owns both Kerr and Ball and is held under a larger umbrella corporation named Newell Brands. Manufacturing for both Kerr and Ball as well as the Canadian brand used is done primarily in Winchester, Indiana. It should be noted that Coleman, Rubbermaid, and several other well-known companies are also held under the Newell Brand umbrella.
The point here is that while the facade of diversity exists with separate naming and use of well-known names being continued, the reality is get which ones you can for the last amount of money as there is no real scientific difference between the two (three if you are in Canada) manufacturers. Unfortunately, this has not been a great review, after all, instead of extolling the values of one brand over another I have shown only that there is only really one brand now.
Regardless, at this point, both Kerr and Ball jars seem to work quite well. And while I am certain there is anecdotal evidence of one being better than the other, if you get a good deal on either you will be doing yourself a good turn. Like reloading ammunition I have found that 2 or 3 lower pressure canning’s are about the limits of the jars. Seeing as I can currently get new jars I prefer to ensure a good solid canning is completed and tend to buy new every year even though we save the old jars as well, (using an indelible marker to date each for future use). Additionally, I tend to use second-hand jars for moonshine and mead as well so there is that use as well.