Couple of thoughts, just to add seasoning to this already well-prepared response...lol.
All honey is not the same. And even from the same source, honey you pick up this month may vary greatly from the honey you pick up next month. This is even more probable from natural, raw, straight from the producer sources, but less so from commercially sold honey. My experience has been that honey adds about 36-38 gravity points per pound. The variability comes from differences in sugar and water content. Like I said, this can change easily. So my point is you can't go with a recipe such as the one you have and expect to get the exact same results simply by adding the same quantity every time. Doesn't work that way.
When I'm shooting for a certain starting specific gravity, or original gravity, I like to add water until I get to about 75% of my total final volume. Adjust for honey content, because you may be able to add more water to begin with for lower gravity meads (i.e., because less room will be needed for the honey). And vice versa. Then I do a rough calculation, using 40 gravity points per pound of honey, divided by the final volume I'm shooting for. Why 40? Because if I use a higher number than the honey will contribute, it's less likely I'll overshoot my OG. ;-)
For example, if I'm shooting for 1.100 OG, and a five gallon batch, I'll put about 3.5 gallons of water in first, and add enough honey to get me close to my target, but just shy. At 40 points per gallon, the math looks like this: 40p/5=100 (40 points times the pounds of honey added, divided by 5 gallons equals 100 gravity points). Solve for p, and you get 8p=100, or 12.5 pounds of honey. Easy.
So that's where I start. Then I toss a hydrometer in, make any corrections for temperature (usually no more than a point or two), and start slowly adding honey while stirring with my handy paint stirrer attachment on a cordless drill. If you're careful you can leave the hydrometer right there in the mixing bucket while you slowly add small quantities of honey, and periodically check in with the hydrometer until you confirm your target OG. Boom.
Hope this helps!