Been reloading over 25 years. Started as a hobby, not necessarily to save money. Have loaded:
7mm Rem Mag
338 Win Mag
44 Rem Mag
I have very little desire to buy loaded ammo for these calibers. I’d rather work up loads to suit my purposes. In some cases, I probably don’t save any money. But in other cases, like the 223, I was able to tailor an accurate varmint load for a prairie dog hunt.
Another time I worked up a very accurate load in 338 Win Mag for a Colorado mule deer hunt. My son was using my 7mm, so I worked up a light load for the 338. It pushed a 200 gr. Hornady at about 2400 fps, was very accurate and easier on the shoulder than the 7mm Mag. Worked great on the deer as well, which took one or two steps before falling over dead.
Recently I’ve been doing some work with service length barreled .357s. With 2 ¾ and 4” barrels and 125 grain bullets, very little velocity is gained using a magnum pistol powder like H110 versus a standard pistol powder like W231. From the difference in muzzle blast, you’d think the H110 was producing much more velocity. But the chronograph says otherwise.
In a similar manner, I’ve also been working with a 18 ½” barreled 44 Rem Mag rifle. Not much velocity difference between 2400, H110, and IMR4227 with 240 gr. bullets in the longer barrel.
If you look at magnum pistol loads in the load books, you’ll typically see increases in velocity as you step through W231 - HS6 – 2400 – H110. And that may be true with 8” barrels. But go shorter or longer in barrel length and the results from the various powders don’t necessarily maintain their relative differences in performance.