drillingI, and probably everyone on this board, do not have all the geological details required to properly make the calls, but here is the way i would do it based on what I know.
Bob says (hypothesizes?) that the limestone is dipping to the East. Briggs and crew should know or have a good idea, based on area geol and geophysics etc. I would attempt to line up my hole to be perpendicular to the dip of the bedding. This would result in true widths of mineralization and would get the most info per foot of hole. Most RC rigs have no problem drilling angle holes as flat as 45 degrees. My first objective would be to get a complete cross-section across the anomaly in an area with the highest values or highest assay x width. This would require a longer hole than that which seems to be the concensus so far. It may even require stacking of holes on the same section to get all the way across.
Some have mentioned going thru the overburden and then just a short distance into bedrock. Remember that all that drilling thru ob is giving you very little geol. info and costs just as much (or more if casing is required) as drilling in bedrock.
Once you have your cross-section, you may be able to shorten up the hole length on subsequent sections. You may be unlucky and hit barren dikes or something similar cross-cutting the limestone beds which means you have wasted the hole. That is why it is important to have enuf $ to test the target in several places.
I am probably in the minority on this, but my opinion is that if RC drilling is 1/3 the cost of core drilling, then drill 3 times as many RC holes with the same amount of $. This is a surface geochem anomaly, so the target should be shallow, and with that strike length, forget the deep drilling in the near term. Others argue that only a core will give you details on rock strength, structure etc. If it is a shallow target (open pit) forget these factors for now. Others argue that core drilling is more accurate than RC because you have a solid core. If you are getting less than 100% core recovery, the RC may be more accurate, and with 3 x as many holes, my level of confidence would be higher with the RC holes.
I really am looking for good results on this one. However, maybe we will get narrow, sporadic mineralization. Then it will be even more important to have more holes to broaden the picture.