Terrible groups....

I got my 550 Set up for .38 spl reloads. I bought a 200 round bag of Berrys 158 gr swc, they are hard cast. Loaded 30 up with 2.8 gr BE. So these patterned to the rigtHnof the black, kind of a larger group than I usually shoot. I should mention I've been shooting Zero reloads, 158s swc, and they shoot well, in my 14-4. QI loaded a batch up with 3.0 BE, same big patterns. I sandbagged 20 rounds at 25 yards, and really no group at all. I'm sure it's not me. I'm amazed at how bad these loads are and how much of a difference they make in my gun. I've ordered some 148 HBWC from Zero and will see how those work. Most of the revolver shooters in my league are shooting the 148's.  I'll need them for the 52-2 I just sent a check for too.  Maybe my Freedom Arms single action will like tHe 158's....
Kurt

Are these plated bullets? For some reason, plated bullets just don't seem to group well enough for bullseye shooting.  I don't know anyone who uses plated. For the loads you mention, I would suggest swaged 158 SWC or 148 HBWC.  Magnus makes some good one.

+1 for Magnus 148 HCWCs w/2.8 BE.

The Zero reloads shot well for me, too, so I tried to copy them. They chronographed at 770fps. I used Zero 158 swc, 3.7gr WST and federal primers. I copied the OAL and crimp from the Zero cartridges. I've never had my revolver in a ransom rest, but this load will hold the 10 ring at 50 yards from sandbags.

OP: One of your problems was the Berry bullets. Might have been your only problem. Very good bullets for 5yds. After that they start going everywhere. That's my personal experience. For WC I load Magnus/Zero 148gr swaged HBWC. For DR legal ammo I use Magtech 158gr RN. The Magtech are getting hard to find.

Len

Berrys are cheap and work great to 7 yards, beyond that it's a crap shoot, or maybe I should say crappy shooting.  That's been my experience.
- Dave

I have shot a lot of Berrys bullets and liked them but only for action shooting.  At 50yds with a RR it was tough to get them to stay on the paper.  It is not the berrys all other brands of coated and plated do the same for me.  X-Treme are my favorites but not for BE.  Also use Missouri coated.  Zero for BE.  Don

Try Missouri hard cast lubricated.  Silver State (owned by X-Treme) are also good CAST bullets.  Plated are a crap shoot.  Coated cast can either work very well or shoot all over.

Two issues:
1) Hard alloy instead of 10-13 BHN. HARD alloy often needs to be LARGER than the hard 10-13 BHN alloy and is not needed for anything until you are way over 1600 fps. It is just easier to get a softer alloy to shoot accurately without leading than a HARD alloy.
2) Cast instead of swaged.
You went from a near perfect swaged bullet of near perfect 11 BHN to a cast bullet that is too hard and may be too small.
I would try Zero 357 158gn L-SWC for $133/2000 (6.7 cents/bullet) and forget the others.
If you must use cast, go to Penn, where his 158gn SWCs can be had in 0.357, 0.358, 0.359, or 0.360" and run $72/1000 (7.2 cents/bullet) for match grade.
Just for those who may not know:
For revolvers you need bullets that are at least a snug slip-fit in the cylinder's throats and are at least 0.001" over actual measured groove diameter. 
I have never used a 18-22 BHN alloy in any of my revolvers, not even my .44 Rem Mags, but when I ordered some cast bullets for .45 and 9x19, when I stopped casting, I quickly learned that the 18-22 BHN alloys they used needed to be at least 0.001" larger than my "soft" bullets, that were already 0.001" over groove diameter and that the only way to get these hard abominations to work was to tumble lube in LLA to prevent leading.

Thanks for all that, explains a lot. I'll measure the Berrys and see how they fit the throats.  I'll report on how the Zero 148 HBWCs shoot after I get them and load some up.