My "platform" is the basis upon which all of my load data begins, and it's NOT that hard. You can analyze, illustrate, debate and tweak till the cows come home but it all ends with one single base. Your case preparation.

My credentials? 42 years of reloading and 32 of those devoted to the 7.5 Swiss cartridge. Load data of mine that was in use long before the manuals figured out that their own data was absolutley erroneous and even based on the wrong rifle. Do I have any magic? Absolutely not. Is there anything mysterious or technically difficult to understand about how I do it? Absolutely not. Have I varied one iota from my original "platform" in case preparation? Absolutely not.... and yet I see a supposed mystique surrounding the reloading for this cartridge evoking all kinds of semi confusing answers that are completely unnecessary.

I won't argue with anyone about presses or dies. This is what works, take it or leave it. Want to use a different press or die set? Go for it. After all these years and many thousands of successful rounds downrange, I'm not changing anything. My daughter gave a seminar on this and had a number of ladies and a larger number of men shooting solid groups in no time at all.

A) Whatever kind of press you have, using RCBS dies, run the ram all the way up. Turn your sizing/decapping die all the way down against the shellholder. Lower the ram and turn the die down another 1/2 turn or so, maybe even less, but make sure that when you run the ram back up the ram "cams over" at the top of the stroke. This is "full length sizing". I don't want to hear about all of the variables in die setting possibilities with all of the other cartridges you use. For the 7.5 Swiss, make your press cam-over at the top of the stroke. Neck sizing? Forget it. After very few times fired your case won't be chambering anyway. Even if you do neck size, your case will have to be hand-fed into the chamber in exactly the same "o'clock" position every time to be effective. I do it with a few of my commercial rifles with some success. 7.5 Swiss? Forget it. Its an exercise in futility that won't shade my loads anyway, and there are at least two local k31 owners that are now believers.
I've used a myriad of presses over the years and the RCBS Rockchucker was my mainstay until the Dillon 550B came along. Though I have a spread of other mfg's dies, RCBS is all I use for the 7.5 Swiss. I currently have 6 sets.

B) Set your decapper to the proper depth allowing just a bit of the tip to appear through the bottom of the shellholder. Screw it in too deeply and you'll bend the shaft and ruin a case. Lock the die into place.

1) Use a case tumbler or a washing machine to get your brass clean. If its a washing machine, put all the brass in a pillowcase, tie the top and wash them in hot water with a good dishwashing soap. Shake all the water out and let them dry overnight on a towel.

2) TTL.... Trim To Length. Our spec will be 2.179 or less. I suggest you don't trim shorter than 2.175.
Ream and champfer the case mouths. If you don't have that little tool, buy one.

3) Lubing: Use a case lube/pad combo or the new sprays which I consider superior. If its a pad, use your fingers to spread the lube evenly over the surface of the pad and roll the cases completely. Use your finger and tip the case mouth down and roll that too. Don't get lube on the shoulders. This type of lube is non-compressible and can dent your case shoulders upon sizing. Use a mouth brush to get inside, but use it sparingly.
Spray: Using a cookie sheet, line it with aluminum foil and lay your cases down on their sides with all the mouths facing toward you. Holding the can at a 45 degree angle, spray from the rear of the cases toward the mouth allowing spray to enter the case mouths. Using the flat of your hand, roll the cases around and hit the case mouths once more very lightly.
Spray lube is not of the non-compressible variety so you won't have a problem with the case shoulders.

4) Lightly coat the inside of your die with spray lube. Do NOT do this with paste lube. Put a case in the shell holder and run it up firmly but gently. If you feel any resistance, STOP! Lower the ram and check the depth of your decapper. Check to make sure the inside your die was actually polished at the factory. This is not at all unheard of. I've gotten 3 of these over the years and they will not allow you to run the case in.
Assuming your ram cammed-over at the top of the stroke, you should now have a properly sized case that will chamber withOUT any real resistance in your chamber.
Have to hit your bolthandle with the palm of your hand to get it to chamber? Projectile seating aside, it WON'T be because you didn't size your case correctly.
I've read plenty of rationale on chambering, and (without telling you how many Swiss rifles I have) None of mine chamber other than smoothly and easily, withOUT rapping.

5) Clean your primer pockets with the appropriate tool. I use a small, formed wire brush that fits the primer pocket. Seat your primers dead flush with the case base.

6) Projectile seating: It is not at all necessary to crimp for the 7.5 Swiss rifles. Crimping introduces a variable that you don't need. The grip of the case mouth on the bullet will not be identical every single time, thus, the unwanted variable.
To determine proper seat depth for any given projectile, keep in mind that the measurement is only valid when the contact of the bullet's ogive and the lands/grooves is determined.
Your manual says OAL is 3.020?... maybe for THAT bullet that THEY used, but ONLY for that bullet profile, not all others. Projectile profiles vary from mfg to mfg. So how do you do it?

There are any number of ways, but I've always used the same methodology. Take a sized, empty and UNprimed case, start a bullet into the case mouth leaving it protruding further than is apparently correct. Place it in the rifle's chamber by hand, ease the bolt into full battery and "smartly" eject it. Meassure that OAL and seat it 2 to 4 thousandths deeper. This is a good start. Later, when you've become more deeply involved in data gathering, you may want to play with seat depths to find the sweet spot for your cartridge. I have specifics I use regularly.
Yes, there are other ways. If you like your way better .......use it.
Once you determine your OAL for THAT bullet, screw your seating die down until the mouth of an empty case stops the descent and back it out a full turn. Lock the die in place and back out the seater.
Now insert case with a bullet into the shellholder and run it all the way up. Turn the seater down till it touches the tip of the projectile. Keep running it up, turning the seater down and measuring until you've reached your previously recorded OAL for that bullet. Do it a few times to assure that it's consistent. Once you're satisfied, lock it in place. Now what???
Find load data that might be in a trusted manual or proven data from the board. Always begin with a lesser load even if the data you find "appears" to be proven.

"Stand up and shoot it like a man!"
Only if Jeff Cooper is watching, otherwise use a bench rest when developing your load data. Use the same rest or bagging methodology every time you shoot. Remove all variables from your data gathering..... and THAT'S the secret, gents. Consistency. Consistency.

Ok, the final step I consider important if you're striving to squeeze every ounce of accuracy out of your Swiss rifles is.............. www.swissrifles.com/sr/pierre/accurizing.html

Does it work? You'd have to ask those who have used the methodology, and there are a lot of them now. I have read a few comments about how it "didn't work for me. A waste of time". It probably was, for those folks. They didn't follow the process correctly and most likely were shooting improper loads with improperly sized cases. ALL of my rifles are accurized, and every one of them improved forthwith.

To wrap this up, I advise that you remove every single variable that you can think of. When reloading, never vary from your case prep (hopefully successful) formula. When shooting for load data, never vary from your shooting stance/position. Record results from every single target you print. Be careful and I wish you success.