Jim Watson
Member
Well, a walk around the block, anyhow.
My "goodie bag" at the Mississippi Showdown IDPA match included a pound of Win. 572. Quick reference on the iPhone showed 9mm data so I did not try to swap it off.
Objective, Minor power factor ammo with 147 gr Xtreme plated bullets.
Like a good little reloader, I started at the book starting load and worked my way up. I went in increments of 0.2 grain because I figured that was about the limit of scale resolution and measure accuracy.
147 gr Xtreme, WSP primer, Federal nickel 9mm cases, 1.142" OAL.
3.5 gr = 803 fps SD 34! f = 118 Starting load, Hodgdon says 855 fps with 147 XTP
3.7 gr = 829 fps SD 19 f = 121
3.9 gr = 860 fps SD 26 f = 126 Barely minor, erratic.
4,1 gr = 929 fps SD 10 f = 136 Much more uniform, CoV 1.1% Hodgdon book MAXIMUM claims 954 fps
I will go with 4.1. It gave a larger increase for .0.2 gr, obviously reaching the "balance point" for good burn. It is a little hotter than I wanted but it is consistent and I am not worried about loading to the book maximum, I do it routinely with HP38 and no broken gun yet.
I will try 4.0 at the next opportunity but if it has a large spread/standard deviation, I will not load it.
My "goodie bag" at the Mississippi Showdown IDPA match included a pound of Win. 572. Quick reference on the iPhone showed 9mm data so I did not try to swap it off.
Objective, Minor power factor ammo with 147 gr Xtreme plated bullets.
Like a good little reloader, I started at the book starting load and worked my way up. I went in increments of 0.2 grain because I figured that was about the limit of scale resolution and measure accuracy.
147 gr Xtreme, WSP primer, Federal nickel 9mm cases, 1.142" OAL.
3.5 gr = 803 fps SD 34! f = 118 Starting load, Hodgdon says 855 fps with 147 XTP
3.7 gr = 829 fps SD 19 f = 121
3.9 gr = 860 fps SD 26 f = 126 Barely minor, erratic.
4,1 gr = 929 fps SD 10 f = 136 Much more uniform, CoV 1.1% Hodgdon book MAXIMUM claims 954 fps
I will go with 4.1. It gave a larger increase for .0.2 gr, obviously reaching the "balance point" for good burn. It is a little hotter than I wanted but it is consistent and I am not worried about loading to the book maximum, I do it routinely with HP38 and no broken gun yet.
I will try 4.0 at the next opportunity but if it has a large spread/standard deviation, I will not load it.
