Wayne-I'm a bit leery of brass stretching. It seems to me you gain length while you loose somewhere else, specifically the head and that's not a good place to loose brass. Moreover, the cost of such equipment is several times more than just trimming the 45-90 brass.
Kitch,
If you read the article you'll find that neither of you assumptions are correct. The brass is not stretched in the head area and for around $40 you can pick up a case stretcher.
Wayne
If you add a few more grains of powder to a .45-70 load that's "Working Well", one may see the REAL accuracy potential from a well managed BPCR ,....one QUITE beyond what's been posted, thus far.
We KNOW what a basically "Plain Vanilla" BPCR WILL, and regularly does) do, and it's just flat WEIRD to try and discern what the OP is trying to do, other than wear out a trimmer, and ARGUE.
OK,....I don't have a damned thing further to say on this particular post.
.....jack chit
GTC