I'm not an expert shooter by any stretch, but I do shoot some nice groups with a lot of different firearms. I have been shooting since I was 4-5 and loading something for something since I was 8. In this time I have shot who knows how many rounds both at targets and game. But in all that time I also practiced a LOT with many different calibers.
That said, with handguns, most will shoot far more accurately than the person behind them, and better than a lot of folks give them credit for. I find rifles are the same way. Many believe that an off the shelf rifle is only pie plate accurate and unless it has an aluminum bedding block and bull barrel on it you will never achieve MOA or half MOA accuracy. All but two of my rifles are off the shelf with the most being done was a bedding job.
Top end loads are just that, and in most cases it takes practice to shoot them well especially in a handgun. There is a LOT more exposure to muzzle blast and concussion from it with a 4-6" barrel than with a 20" one. Even if there isn't a lot of associated recoil involved with the load, that alone starts to get in the mind of some shooters and they start to get itchy about pulling the trigger. Others aren't bothered at all by the flash or bang but throw in some recoil and they get the same way. Everyone is effected by things differently.
Tailored loads are just that, they are put together for a specific purpose and should be treated as such. Just pouring powder in the case and seating the bullet to the same depth every time is loading, but not tailoring. Once you start to prep cases, adjust seating depth, swap primers, and bullets of the same weight, then your getting there.
I have both rifles and handguns which will shoot just as accurate with top end loads as they do with bottom end ones, and with some there is a world of difference once the charge is lit. When I got my 454, I could shoot it, but it took nearly 3 months of shooting it to become accustomed to the blast and recoil where I could shoot it accurately. Once there it still takes regular practice to stay proficient.
Some powders produce a more energetic recoil impulse even on the low end whee others are nice and smooth. Take the age old target load for a 45 ACP of 4'ish grains of Bullseye under a 200gr cast SWC. How many times has this combo won a competition? Change the powder to Unique, and you can still get those type groups but your recoil is a bit more snappy.
Same with rifles, a 243 loaded with H380 under a 100gr bullet has a nice pop to it, but switch to a similar velocity load using something like 4350 or 4831 and it is still a pop but not as sharp due to the lower powders. On the opposite end of that, I load 3031 under a 130gr bullet for our .270 which gives me right at 2800fps. Very sweet load and VERY accurate. Take the same bullet over a load of 4350, and the recoil, while being close to the same in FTLBS seems to be a bit more harsh. I cannot say for sure as I have never measured it just going by what the book loads say, and the reaction to them from my daughter and my oldest grandson who both seem to prefer the 3031 loads over the rest. Don't get me wrong, they will both saddle up behind anything, but they also have their preferences as well.
I personally found that the CFE Pistol has a decent pop to it even on the low end loads, but I can shoot it very well. Throw my friend behind the same loads and he is all over the place with it. Drop down to the start loads with AA-5 and he is tearing out a ragged hole. Similar velocity from both loads but very different felt recoil.
