>38spl. and .357 SWC COL for SNS 158gr Hitek bullets

Hi, fellow enthusiasts. 
 
For 38 Spl. I load two styles of projectiles for my S&W model 27-2 6in. Loading and shooting 148Gr HBWC from Delta Precision and the SNS 158 gr. SWC Hi-Tek set at 1.415 COL for Bullseye. The 148gr. sure leaves very little airspace in the case. The 158gr if COL at 1.540 or so max leaves quite a bit. Hence my 1.415 COL.
 Currently looking to use up my old AA#5 and have the load set at 4.3gr. Shoots OK. Other powder choices are Unique, Bullseye, VihtaVuori N310, and N320. I suspect I should use the Unique due to the larger flak size and displacement.

 I have not loaded for the 357 magnum yet.

 I thank you all for your experienced opinions in advance.

 GJG

I suggest seating to the crimp groove on the 158 and crimping into the groove. The bullet design along with published or proven load data have taken the resulting air space and pressure into account. 

My powder suggestion is bullseye or unique. 

I have been working on 38 loads using 158 SWC and round nose from Brazos (my preference is round nose). From a 4 inch GP100, 3.4 Bullseye and 4.5 Unique will make groups a bit over 1 inch off the bench at 25 yards. Both are a touch under Allliant’s data listed on the web. https://www.alliantpowder.com/reloaders/recipedetail.aspx?gtypeid=1&weight=158&shellid=26&bulletid=30

Good luck!

Dave

A few years ago, I loaded some 357s with 158 cast lubed bullets.  I usedWW540 (identical to Hodgdon HS6).  I seated them to the crimp groove.  I haven’t shot many, but those I did shoot seemed to be accurate enough.