I built a 45 cal flint minuteman "kit" in the late 1960s with a numrich barrel. It was an absolute piece of C**p. BUT, i did get an introduction into the world of "how to fix everything" and learned a great deal about repairing bad inletting, poor architecture, cheap hardware, lock refurbishing etc. Not joking, it needed everything redone. When finally re-done it was an example of what a very bare minimum quality rifle could possibly be, BUT it shot exceptionally well!!. Used 445ball and 18 patch with 75 gr 3f. Maybe the best 100 yard shooter I've ever owned. So to answer the OPs ? Yes those old numrich barrels can shoot very well.
Not relevant, but I'll share this; when I opened the package and was looking at the parts, I saw what looked like a speck of light coming through the breech plug. I poked it with a needle file and it went right through! Sent it back and they returned it saying it was fine. I sent it back again saying it was NOT fine and they sent it back with some brass brazing fill. Being a young kid I accepted that and used it for several years. Finally wised up and installed a new breech plug. A true piece of garbage but it started me on my lifelong path ,