Ruger SP 101

[jon308]

First off Im new to the 38, 357 platform, I have re-loaded other calibers. I want to stay with 357 cases and not purchase both at this time, Can I load a 357 case down to 38 spl velocities . Say 6 grns of unique, Also if I can do this what dies do I need, And if this is not going to work and I must use 38 spl cases then what dies do I need to do both cases.
Also for those with a lot of experience on the 357 what bullets are more accurate 125 or 140 for plinking and small game hunting. Thanks

[Pasley]

The same dies will work with both. You should have no problem loading down as long as you are using a relatively fast powder like Unique.

[SlimMan]

Use your manual and if you don't have one, buy one.

With that out of the way....You don't need to use 38 sp cases, in fact I prefer always using 357 cases--less chance of fouling buildup in the cylinder with the longer case. Just use the start loads in your manuals using handgun powders with fairly fast to mid-range burn rates (e.g., Bullseye to Unique burn rates are pretty good choices, but stay away from the slower 296 and 2400 powders unless moving toward full power loads) and you'll have a soft shooting round out of your SP101. 148 gr LWC and LSWC are pretty hard to beat for light/accurate plinking loads.

[Wildcat]

If your SP101 has adjustable sights, your job will be easier. For fixed sights, you will need to tune your load to the gun.
I'm sure you will find a commensurate level of accuracy to bullet quality and your loading consistency.
Usually with fixed sights, a heavier bullet will more easily meet point of aim; say, 140gr to 160gr.

I also prefer to use 357 brass, even for 38spl loads.
A magnum-small-pistol-primer will help Unique to burn cleaner. 6 grains is a lot of Unique for a 38spl though. Find a couple of loading manuals and see if they provide information about the bullets you have. If you are using plain, lead bullets it is generally recommended to keep them under 1000ft/s unless they are particularly hard cast.