From reading, it appears that the 150 grain SWC is more accurate than the 158 grain SWC, is it significant enough to pursue a vision quest?

One thing that stood out was the use of more powder (5.4 grains Unique) with the 150 grain SWC compared to the 158 SWC. (5.0 grains Unique)

There are so many variables that I think would very hard to prove. It could be in your gun better or worse, I'd be inclined to try some and then just go with availablity and cost. Chances are if you have enough time you could come with loads for both bullets that were just as accurate as the other.

Using a Forster hollow point attachment on my trimmer, I've drilled out 158 grain SWC's on occasion and "converted" them to 150 grains. The 5.4 grain Unique load was recommended in the old Lyman manuals and is a good load. I continue to use it for 158 grain loads and also in the few drilled out bullets I have done. Velocity of the 158 grain loads runs around 890 in my Model 60-7. Not so shabby, and it usually goes along me in my pocket when I'm out with the .22 rifle for squirrels, walking, etc.

I certainly haven't done any exhaustive comparison between the two bullet weights mentioned from a more suitable gun such as my 14-3 or 15-2 but offhand I wouldn't expect the accuracy to be so much better (if at all) with 150's to justify jumping through a lot of hoops to rustle some up. I used to cast my own in the Lyman #358477 mould, but no longer.

158 grain SWC's are pretty much the standard for a reason.

From 150gr to 173gr, I probably wouldn't change the recipe any. Most of my 38spl guns will take the extra thump. That being said, I'm sure I'm not going to change the recipe much from 150gr to 160gr.

FWIW

As have been said, there are so many variables there's no way to say that for certain for all handguns.

I shoot a 158gr LSWC with a charge of 4.0gr W231 and find that is the most accurate .38 Special load in my revolvers. That's not to say it will be for you, only it works for me.

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SWCA #3437

I picked up this old Lyman mold last year with handles for $25 it's a 150 gr. It shoots great in my 38 loads with 3.5 grs. of W231 or HP-38.



I got this mold also for $25 it's a 160 gr. and also shoots well with the same charge.



Both molds has the last bullets that were cast still in the mold that the old guy who passed away had left in them,they have a prominent place in my reloading shack.

I have pursued that vision quest using a 150 gr. cast bullet design intended for the 38 Super. That bullet has no crimping groove of course so I taper crimped it. The load was accurate but it didn't gain me anything over the 158 gr bullets.

If you have a fixed-sight gun and it's hitting high with the 158 grain SWC, then the 150 might be a good alternative.