Like Dimner said you just won't know until you try and see what works in your rifle. Maybe into the lands is not the best option. That's all I'm pointing out. I would like to know when shooters started jamming bullets into the lands. Is it from the black powder days? Really, when did competition shooters start? Or have they always.
Technically speaking, jamming the bullet started with the first firearm, the ball was pushed down the barrel onto the powder. Into the lands started later, when rifling became popular vs smooth bore. Jumping, from powder charge to barrel started with the first non cartridge revolver.
There is whole lot of loading styles that have come and gone and then revisited with time and refinement. Competition started after about 3 people in the same area owned firearms.
Early cartridge rifles were more like 22LR, the bullets seated into the rifling, more just engraving vs “jammed”. More than a touch.
Many of the early cartridge competition and hunting rifles certainly used a hard jam. To the point that special tools were used lever the cartridge into the chamber. The action closing did not have enough mechanical advantage to be able to force the bullet down the bore. The other thing the seating tools did was insure the cartridge and bullet were seated straight into the bore.
Then there is breech seating. The bullet started down the bore, then the charged cartridge inserted behind. The bullet generally seated so that around half the base band was into the rifling, 1/6” ahead of the case. This insured the bullet was placed in the same spot in the bore ahead of the case each time. Considered one of the more accurate methods of the day.
Then there is what many thought was the ultimate method. Muzzle loading. The rifles seating tool was indexed to the muzzle. The bullet started down the bore, then pushed home with a ramrod to a specific depth. The charged case inserted from the breech end. What this does is eliminate the fins created on the base of the bullet when the rifling creates the grooves. You have a custom swaged bullet to fit your bore.
It’s really only since the adoption of jacketed bullets that jump became popular.
You mentioned 300 BLK. The absolute poster child for accuracy challenged cartridges. The chamber was designed to use any old scrap brass you might want to cut down and form, then also to accommodate a .309” cast bullet. So if you use nice brass like Lapua, with a .010” neck in a .336” chamber, the cartridge flops around like a fish due to .008”+ clearance even if you neck size only. Add in a .300” jump for some short or VLD type bullets and it’s tough to get sub 1/2 MOA groups for good reason. But it can be done.
Different methods can be more or less time consuming to tune. Some consistently have better results. It as you said, it’s a choice. Squeezing the most accuracy/precision out of different cartridges will vary.