pre 1950 K frame reloading help

[rojo]

Hi guys , I require your advice, I am planning on doing bulk reloading for my 1930- 1948
S&W k frame using the Lyman 357446 Thompson SWC bullet with the AOL of 1.457 utilizing the
lower crimping groove.
The revolvers are of following a 1932 M&P, a early post war commercial victory, a WW2
Victory & a 1948 C series M&P snubby.
All revolvers are safe to fire and are in very good to excellent condition.
The plan is to have a quality reloads with the same point of aim as 158 gr factory police loads.
I plan I using 4 to 4.4 grs of Unique, I am concerned if these loads may be too much for
these vintage revolvers, any suggestions would be appreciated.


Happy Holidays,

[35remington]

I'm not sure why you're using the lower crimping groove. This increases airspace in the case, lowers velocity with a given powder charge, increases shot to shot velocity variation, and was originally intended for seating the bullet out with heavy loads that take up a lot of powder space which is not your condition.

Your loads are standard velocity equivalent as is and safe for revolvers of this vintage, which are not rated for Plus P. Crimp in the upper groove, use your contemplated loads and be done with it.

[Char-Gar]

Smith and Wesson did not rate their K frames for +P pressure until 1957. Revolvers made prior to that will wear at an accellerated rate with higher pressure ammo. Pre-War K frames are even a little softer.

Here is my rule of thumb for these pre-war K frames in 38 Special;3 grains of Bulleye, not to exceed 3.2 grains.

Post-war guns are good to 3.5 grains of Bulleye.

I don't favor Unique in these handguns, but my gut tells me you will be OK at your level. However, I will let others more familiar with the ends and outs of that powder fill in the blanks.

I can tell you that these sixguns will shoot to the sights with a 155-160 grain bullet over 3 to 3.5 grains of Bulleye.

Bulleye is such a good pistol powder that it is all I use in 38 Special, 9mm, 45 ACP, 45 Auto Rim and 45 Colt cartridges.

[Outpost75]

Your proposed 4.4 grain Unique charge should be used in the older S&W Hand Ejectors (pre-1957) ONLY when the bullet is seated long, using the rear crimp groove for 1.55" overall cartridge length.

If deep seating the bullet and using the front crimp groove at an OAL less than 1.5" OAL, do not exceed the 4 grain charge or 3.2 grains of Bullseye, as indicated by Chargar.

S&W does not have parts for or service its pre-1957 revolvers any more. If you loosen up your older S&W .38 Special Hand Ejector by shooting heavy loads in it you will turn a $500+ collectible into a $150- paperweight, if you get lucky in cannibalizing it for parts and selling the salvaged pieces to Numrich.

[35remington]

Allow me to point out that 4.7 to 4.8 grain charges of Unique are considered to be upper end of the standard velocity range with 158 grain SWC's in the 38 Special. Higher charges are plus P. At the upper crimp groove, the 162 grain 357446 approximates the seating depth of the various 158's, and the contemplated upper end charge of 4.4 grains is below the standard velocity upper end for the 38 Special for reasonably comparable 158's by a noticeable margin.

Since you've bumped the charge below that allowed for the 158's by a noticeable margin my opinion is you're upper end for standard velocity in the top crimp groove, but within that margin.