Thanks Flint, we'll check that out on the next few and report results.
On most hogs...most places, it is surprisingly accurate. When I first started using the method (probably 10 years ago) I made it a point to weigh the hogs and compare. I stopped weighing after a couple dozen...because the tape method was pretty darn close.
I'm sure my scale isn't 100% accurate, but the figures were plenty close enough.
Naturally, there will be places where hogs have better habitat than others so some variance is to be expected.
Also, pregnant Sows will weigh more than the tape suggests, since they are 'heavy' aft of the area (heart girth) to be measured.
Boars with especially long hair (particularly if caked with mud) will come in a bit under what the tape suggests...because you can't pull the tape tight enough to the hide.
Still, it serves me well for most hogs.