Dang it, the American way. Throw money at the issue till your satisfied by the results. Your idea will work, give lots of data to work with and you will find something that works. From years of doing this I have a few suggestions. Load 10 of each type as mentioned about 7-10% below maximum on chart for each powder. That will be 20 rounds per bullet. Shoot 5 round groups and when measuring size only use the 3 best shots so human error is minimized. Get either a folder or 3 ring binder and write load combination on the Target shot and save for reference years from now when your head starts to overflow from data. You will see a definite pattern emerge.
Find your best 3 to 5 groups and work with those. Build loads again with same bullet powder combo but 1 that is 3% lower and one 3% heavier charge and repeat. Patterns will continue to emerge and follow them continuing to vary charges till your group sizes start increasing or you see signs of excessive pressure.
When you go to the range remember a clean bore is different from a fouled bore. Take a box of factory ammo and fire a group to foul the bore. Save this group to compare with your loads. Also a cold rifle shoots different than a hot one. So variations in bore cleanliness and temperature will affect results. I take a non contact thermometer to the range and a fan. After each shot or group I open the bolt and let the fan cool the rifle a tad. While exact same temperature for each shot is impossible, don't compare a.group from a cold rifle with one that the chamber was too hot to touch. Every 30 rounds or so, run a brush down the bore then shoot a fooling shot to recondition it for consistency.
Other things to note. The shape, i.e. ogive, length, etc is different for every bullet. So if you seat them all the same depth, the distance from where the bullet starts until it engages the rifleing will be different for every style which makes your comparisons view on an unlevel playing field. If you are as serious as you sound due to just dropping several large bills on bullets, a device to measure the distance from your bolt face to the lands of the rifle then set the seating depth of each bullet so you know the amount of "free bore" is imperative. As you figure out which bullets and powder your rifle likes then you can start adjusting the distance from bullet ogive to lands and see if it helps or hurts group size.
Then you can try different primers with your loads. Standard, magnum and match from at least 3 manufactures. Also you can decide whether to full length size or neck size. Then you move to neck turning. Inside champhering or outside turning or both. Maybe you want to start with the actual parent case for your caliber and form your brass for it so you have more neck thickness to play with. Then you can do a chamber cast to determine inside diameter of your chamber. Take that info with the outside diameter of the bullet then some basic math will give you the information so that you can neck turn in a manner to adjust your load for minimum neck clearance in the chamber.
Ohh, I mentioned primers before. Remember to uniform your primer pockets then debur and uniform the flash holes. After you have Spent hundreds of hours getting your cases perfectly matched to your.chamber then you weigh them and match them in groups that weigh close to each other so each fires group is from as nearly identical brass as humanly possible. About a 1,000 rounds into this process you will be a better marksman instead of a shooter, a handloader instead of a reloader, have the perfect load for your rifle and then decide your ammo is better than your gun so you have to get someone to build you a better rifle to match your ammo making skills, then repeat this process for the new rifle until it and you are tweaked.
By then you will be showing up at the range with a chronagraph connected to a laptop with your favorite Ballistics Lab software, looking for smartphone apps to use on the field. Taking more time setting up your mid-range and target location wind flags, checking the wind speed and direction at the bench before every shot. You might even go so far as to attach a direct contact thermometer to your chamber and hook it to you NIST calibrated Fluke HVAC thermometer with humidity feature and dual temperature capabilities so even relative humidity is figured into your shots along with ambient temperature and bore temperature. The computer becomes a necessity to log all this information so you have time to shoot and do your meditation. Yes, you must clear the mind so that all you know down to every fiber of your existence is sight placement and trigger control. A clip on heart rate monitor also helps once you have completely gone down this road. Keeping your heart rate under 60 bps and consistent from group to group makes a difference.
If any of y'all think this is fantasy well it isn't. Welcome to my world of obsessive compulsion. In fact, I have left out as many steps as I have mentioned. We can talk about annealing the brass and most consistent techniques. Brinell hardness testing of both your bullets and brass. Do we try a partial setback of our necks? Dang, don't know till you try. So you buy a new rifle and about 5 years later you have it shooting satisfactory but guess what. Some stinking company or 3 come out with new bullet designs that might be better so we better give them a check. Pull out that folder for your rifle, order the new bullets and let's go back to the bench and the range.
Daggum, I think if I try this new wildcat cartridge that is all the latest buzz I might tighten up my 400 meter groups. Let's see... what action is the stiffest for that overall cartridge length? Where are the chamber readers available? Do we "Blackstar" or cryofreeze the barrel or both? Who has the best bedding material these days? Traditional or thumbhole stock? Synthetic or lamented? Magazine fed or single shot? Off the shelf benchrest scope, what magnification, do I have it "blue printed"? I ought to just quit this sport.... Nahh, think I will go ahead and order that barrel blank while I contemplate the rest. At least since I have to buy a chamber reader having the dies made are that much simpler...
