I have more than a little bit of experience of bracketing I've got to say
It was me that told Gary Cooper about the hinge to centre of killzone method probably about 4 years ago now, and I also had some input into the design of the SCB ret - the floating crosshair for example was my idea.
The difficulties with bracketing are that it's easy to miscount the number of increments - especially when you're in the middle of a competition when the pressure is on. It's also not always easy to keep the rifle perfectly still while taking a measurement and a difference of even 0.2 of a mildot is enough to put you waaaay off on range.
I wrote a training manual on this subject years ago and I also developed a quick online quiz to help shooters practice this method.
Here's a test to help illustrate some of the difficulties you'll face when trying to bracket a target.
> Online Bracketting practice test <
(Your browser will need to support FLASH in order for this test to work)
Measurements are taken from the Top of the hinge plate to the centre of the killzone - there's a range card next to each example for you to read off the range from - see how accurate you and perhaps post the difficulties you find by doing this test and what method you used to overcome those difficulties.
Hint - the hinge plate is about an inch higher than the baseplate.. it's clear to see on some targets, not so clear on others, but these are real photo's of targets from a real course - so this should help to illustrate that bracketing isn't as simple as it seems.