I shoot a Savage 112 BVSS-S Swift and found a node way up the ladder using 52 gr. Bergers and a large quantity of 4064. I shot 37.3 grains for quite a while but found 43.0 grains gave the best accuracy. It is hard on brass and barrels but why own a Swift if you don't push the envelope. If you try something in that range approach cautiously and in small increments.
I am not really worrying about brass or my barrel. When my brass or my barrel wears out, I will just replace it. I have just been working my way up through different bullet and load combinations looking for the most consistently accurate one. I still have a lot of room at the top before I am done. To me that is a big part of why I like centerfire. If I could reload 22 Magnum brass, I would be doing that as well. It is the ability to develop a load specifically tuned to your own rifle and then to be able to repeat that load to tenths of a grain that makes the centerfire more personal than rimfire. No factory is ever going to be as careful as I will in loading my ammunition.
I realize my current best load is just that. I also know each rifle works best with a load specific to that single rifle, so there is no way to be sure until you do the testing.
What I see rimfire shooters doing is spending their money tuning the rifle to the ammunition. That would would a better plan of action if the ammunition makers would be more consistent in what they offer. Instead, they seem to keep dropping popular ammunition and offering different loads, while letting quality control slip and raising prices. In another forum, I recently wrote about finding a cartridge with a split case in a brick of Fiocci 22 WMR this week. Checking the box, I found the ammunition was manufactured in the Philippines, for Fiocci of America. Now I feel the need to hand inspect each of the 500 rounds in that brick. So who is doing the quality control??
Don't misunderstand me, I have three rimfire rifles and two rimfire pistols, so I am not some centerfire purist. I have no intention of giving up my Martini 12/15 .22LR or my LH Precision 22WMR/17HMR Switchbarrel. Each is a cool rifle to fire. My only gripes are the rising cost and dropping quality control of the ammunition for them, along with the inability to make my own.
I fear I have just about worn out this topic and am starting to repeat myself but I am still interested in other shooters' comments and experiences.