Just my experience here:
1. The brownells $100 wall gauge is nearly unusable and gives rough estimates. (owned and returned one)
2. The hosford gauge is so-so
3. The galazan gauge (just like the type used at every famous maker) is expensive but idiot proof. I love mine.
4. Truth gauge only does about 6" of measuring making it a poor tool unless the goal is crude estimates at gun shows.
Long story short, I found anything short of the classic wall gauge "towers" to be a big disappointment.
With all due respect, the gauge that Brownells sells can be as accurate or inaccurate as the Galazan once modified. I've used both. I've used gauges professionally for 20 yrs. Some are easy to use and require little technique. Others require a learned technique, some even require modification. The inexpensive Brownells gauge requires both of the latter.
The late Dr. Gaddy showed a spring modification to the Brownells gauge which made the Brownells gauge work reliably. Here's a picture of one that Rabbit modified in this manner.
Also, modifying the end to enable it to hung vertically minimizes the bending of the rods.
