.38 Load Data

kenn2050

I found a box of .38 160gr LSWC that I would like to load with some Unique but can't seem to find any data on 160gr for that bullet type. Anyone have a starting load or can I use the data for the 158gr?

Rocky Raab

Use the data for 158. Most of the bullets I cast that are labeled as 158 turn out to be 160-162 grains.

jonk

It's very common for actual cast bullet weight to vary +/- 5 grains depending on alloy used.

For a 2 grain variance I'd say you're just fine. Most published loads include a small fudge factor. Even max loads probably don't really push the limits for most cartridges in most guns but just approach them.

Sometimes this 'fudge factor' is ridiculous. Look up loads for the 8mm Mauser sometime and have a laugh. Their 'max' loads (at least in several of my books) not only are ridiculously low, but their chronograph data is way off. Sorry, 35 grains of 4064 is NOT a max load in an 8mm Mauser, nor will it produce 2400 fps. FWIW with a 150 gr bullet something like 50, 51 grains would be a good top end load with that powder and bullet weight in a 98 action.

I just provide this for reference. Anyone worth their salt publishing load data wants to make sure you're safe and a 2 grain variance in bullet weight won't hurt anything assuming a good condition modern gun chambered for the ammo in question, even with max loads. The 158 gr data will be fine. The only caveat I'd offer is make sure you're talking a 158 gr semi wadcutter as pressure might be higher than with, say, a 158 gr round nose due to increased bearing surface.

But even then you probably won't want a max load with a lead bullet anyhow.