With factory ammo I’ve have my best performance with Federal/Eagle 158gr JSPs. However, I get the occasional pierced primer with this brand of ammo, in two different revolvers as well as my Handi. For the past few months I’ve had a chance to experiment with heavier/longer 357 magnum loads originally intended for the Contender. In Speer Reloading Manual #9 there are both rifle and pistol loads for the Speer 180gr (.358) JFP intended for the 35 Remington and in the Lyman Manual #47 and their Pistol Manual there are loads for a cast 200gr RN (available from Western Bullet). With the longer barrel of the Handi Hogdon’s H110 gives the best performance to date. At the range the Speer 180 JFPs easily group into 2” at 50 yards, while the cast Lyman 200gr loads open up to 3” to 4”, have only been to range once with the cast loads so more load development is required. Closer in Remington 125gr JHPs shoot well too but have not tried them at 50 yard only 20yards.