I did some more testing of the MBC 148gr coated DEWC bullets this weekend.
At this point I am playing around with the crimping to see if I can get that elusive small grouping. Based on all my results so far, I think the grouping size is more a result of my inability to aim consistently with the Ruger SP101, instead of the loads.
Following is the chrono data for the loads I tested:
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, 700X, 2.1gr, WSP
Average: 500
ES: 27
SD: 12.6
Force: 82
PF: 74
Velocities: 488, 486, 507, 513, 509
The 2.1gr 700-X load was a very soft load. Actually most of the 700-X loads were soft shooting.
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, 700X, 2.2gr, WSP
Average: 524
ES: 19
SD: 7.5
Force: 90
PF: 77
Velocities: 512, 528, 531, 528, 524
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, 700X, 2.3gr, WSP
Average: 545
ES: 21
SD: 9.1
Force: 98
PF: 80
Velocities: 534, 555, 546, 538, 553
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, 700X, 2.4gr, WSP
Average: 580
ES: 24
SD: 10.7
Force: 111
PF: 85
Velocities: 570, 589, 594, 576, 572
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, Bullseye, 2.7gr, WSP
Average: 644
ES: 19
SD: 7.7
Force: 136
PF: 95
Velocities: 657, 641, 647, 638, 640
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, Bullseye, 2.8gr, WSP
Average: 666
ES: 28
SD: 13.5
Force: 146
PF: 98
Velocities: 680, 680, 654, 667, 652
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, Bullseye, 2.9gr, WSP
Average: 688
ES: 15
SD: 6.8
Force: 156
PF: 101
Velocities: 697, 682, 688, 694, 682
SP101, 38spl, 3"
COL: 1.210"
MBC, 148gr, B12HTDEWC, Bullseye, 3gr, WSP
Average: 714
ES: 40
SD: 16
Force: 168
PF: 105
Velocities: 723, 709, 722, 689, 729
Following are the targets from some of the better groupings I saw. All the testing was done with a Ruger SP101, 3" barrel and open standard sights at 10 yards using a rest. It seems that I always have a decent grouping and then one flyer: