I have ken water's pet loads. Off the top of my head, he said that jack o'connor said that 62 of 4831 was an optimum charge... Don't go by my faulty memory though...
Still best to work up the load, even the bullet type or shape, not to mention weight and construction, seating depth, brass capacity, will all affect the optimal charge weight. Hence that pet load might be too hot for the OP's gun, it might be too slow, or it might be perfect. Always a bad idea to take someone else's pet load for anything more than a curiosity and maybe something to keep in mind during working up your own. The most it is worth though is an interesting point if yours ends up with his. The biggest reason we hand load is to get the best ammo for our guns...If we just take other people's pet loads without developing them in or gun, we might as well shoot factory ammo, since the amount of time (don't know about you guys, but my time is worth a lot to me, so if I'm spending a bunch of time on something it better be worthwhile and not just for cost savings, as it would be pretty hard to have true cost savings at the rate I Bill myself out at). Having said that, a lot of guys DO just take someone else's pet load, maybe load up a set or two below and a set above that and call it a good starting point. That is certainly a lot more valid, if you are using a similar gun with the same bullet, otherwise it's absolutely best to just start at what you would consider, based on reloading data, a good starting weight. I rarely will bother with the lowest 25-40 percent of the stated range in the manual, as I have found, and can be quite confident in the fact, that anything that low in the range is not what I want anyways.
To the op... your best bet for load development is to either way for a less windy day, or at the least, try to shoot in a direction where the wind is full value (I.e. 90 degrees to the direction of bullet travel). This will take out most of the vertical dispersion due to wind. Of course wind changes direction, so you will end up with some shots that are lower or higher by a little than they should be, but it's better than shooting part way into or out of the wind, as then it has a larger effect on the velocity of the bullet and, any changes in direction or wind speed are going to be much more significant at angles bigger or smaller than "close to 90"
Also you may be well served to just throw a good bipod on your gun, get a sock or three and fill with rice, sand, or lead shot, and do your load development from prone instead of on a bench. How stable is your bench? If you can wiggle or move it then you want a different one for load development.. Remember changing the angle of your barrel only .318 degrees will move you off target by 20 inches....that's not very much movement. It's a change in muzzle position by only 140 thousandths of an inch. Heck moving the barrel angle by only 0.0796 degrees (35 thousandths of an inch muzzle movement on a 26" barrel) will put your shot off by five inches.... This shows how critical it is to keep the gun steady....you could end up, by random chance, choosing a load that really isn't nearly your best one. Also increasing the number of shots per charge greatly reduced the error in every way. Even the human error part, since if you are decent with your gun, you might have one or even Terry shots that are less perfect than the others, so with three shots that destroys your data, but with 7 or 10 shot groups you are much more likely to end up seeing useful data from most of your shots.
Good luck!
but short of that, remove whatever variables you can, especially the ones that affect vertical dispersion, and just ignore the horizontal for now.
