The 357 Magnum is the same 158 gn SJSP loading sold under the American Eagle brand and it's an excellent 357 Magnum target load although a bit expensive for target shooting. In addition I find the recoil of this load to be a bit of a flinch builder for me so I limit my use of it. BTW, muzzle energy is "only" 600 ft.lbs. so it's not a max load, however it is a true Magnum and is also loud enough to get some attention at an indoor range.
The 38 spl. hasn't show up at any of my local Walmarts yet. However I have seen it listed on Fin, Feather, & Fur's web page and see that it's a LRN loading. Prior bad experience with the Blazer 158 gn LRN ammo in the ECM barrel of my model 620 has led me to ONLY shoot jackted ammo in an ECM barrel. I would suggest you avoid this load if you know you have an ECM barrel, if your barrel uses conventional rifling it will probably be just fine.
As for the Federal Champion brand, I've shot a lot of it in both 40 and 45 ACP and IMO it's an excellent range ammunition. In total between the 2 caliber I've shot off at least 3000 rounds and only had one single failure, a dud primer in the 40 caliber. Casings are always brass, it's clean shooting, and I've found it to be quite accurate, so it's an excellent choice for range use. However, the power level of most loads is a bit reduced compared to Self Defense loads so you need to plan on shooting some of the "good stuff" from time to time to keep current with the recoil and noise of your chosen Defense load.
