There is a fellow named Jerry Lester who posts over on the Marlin Forums who has shot a large number of deer and other critters with his Marlin 1894 .357 mag. He is a believer and will be happy to communicate with you and share his experiences. It seems he spends a large amount of time in the woods, and it seems he fires more rounds of ammo at critters and at the range than most of us. He really likes the Remington bulk 158 grain JSPs tht can be ordered from Midway for really reasonable prices. He also shoots lots of the bulk Remington 125 grain JSPs for smaller game and varmints. He shoots both the Marlin and a Ruger handgun with these loads. I won't trust my memory to share with you the loads that he uses, but if you can make contact with him, he will be glad to do so. As with any load and firearm, there are limitations, but for the ranges that he usually finds deer in the east, he is plenty satisfied that the .357 mag is more than adequate if you can put it where it needs to be put. That range is 100 to 150 yards, as I recall.
I also shoot these Remington bullets in the same rifle and Smith handguns. I do not have the opportunity to shoot at deer much, so cannot say personally about the effectiveness. I can tell you that either round from the rifle will turn the underside of a coyote to the sun, especially at ranges they are normally shot when calling. I can also tell you that they positively knock the hair off a jack rabbit. Sounds like a ball striking a catcher's mitt. Good cheap shooting!
