We recently had a customer bring a Rattler .357 into the shop for some testing.
The shroud and stock moderator can be removed, and we found that the #S21 Ronin was quieter than the original setup with no point of impact shift. You will need the M14x1 custom threaded cap.
https://donnyfl.com/collections/ldc/products/2-x-6-5-inch-ronin?variant=13286078251051
We also tried the #S5A Emperor and it was a little quieter yet, but the point of impact did drop a little. You will need the M14x1 custom threaded cap.
https://donnyfl.com/collections/ldc/products/2-x-10-5-inches-emperor-v3?variant=14050945073195
The threads on the bare barrel are M14x1 on all calibers .22-.357, so if you do order a moderator you'll need to specify that you need an M14x1 endcap. This is a custom endcap, but we will not charge you for the custom work if you are buying the moderator at the same time. Be sure to put the note "Needs custom M14x1 endcap" in the special instructions box in the shopping cart.