bangerjim
01-10-2014, 03:08 PM
I cannot find Unique. I have lots of TG ( and others).
There are some cal's that U is listed but TG is not. I built a little spreadsheet and grabbed data from Lyman CB book using known starting loads for the two powders as an example:
Unique
4
4.4
4.1
5
3
5.4
4.5
4.6
4.5
3.7
3.7
4.0
4.2
8.9
7.5
8.6
6.0
7.4
6.3
6.0
4.8
5.6
TightGroup
3.2
3.4
3.3
4
3
4.3
3.6
3.7
2.9
3.1
3.0
2.9
3.2
6.3
5.3
6.1
5.6
5.3
5.6
5.6
3.7
4.4
ratio
1.3
1.3
1.2
1.2
1.3
1.3
1.3
1.2
1.6
1.2
1.2
1.4
1.3
1.4
1.4
1.4
1.1
1.4
1.1
1.1
1.3
1.3
28.2
AVG
1.3
(sorry for the cramming, but that's just the way it cuts & pastes into here from Excel. JPG was only 1/2" long!)
The average difference is 1.3gn in the various verified load data. This is from 9, 38, & 45 charts.
TG is a much faster powder....#14 vs #31 according to Hodgdon charts.
Question is, can one use that ratio of ~1.3 as a good starting point for pistol loads that do NOT have TG data but do have U? I know this does not take into account CUP or other factors, but the load data for most pistol powders seems to be within a grain or so of each other anyway. In no way am I proposing anyone use this simple mathematical solution for MAX loads!
I am sure there are others out there that are pondering the same questions, what with the extreme regional scarcity of certain powders on the shelves.
Looking for a little input from those wiser than I in the venue of powder loads.
bangerjim
There are some cal's that U is listed but TG is not. I built a little spreadsheet and grabbed data from Lyman CB book using known starting loads for the two powders as an example:
Unique
4
4.4
4.1
5
3
5.4
4.5
4.6
4.5
3.7
3.7
4.0
4.2
8.9
7.5
8.6
6.0
7.4
6.3
6.0
4.8
5.6
TightGroup
3.2
3.4
3.3
4
3
4.3
3.6
3.7
2.9
3.1
3.0
2.9
3.2
6.3
5.3
6.1
5.6
5.3
5.6
5.6
3.7
4.4
ratio
1.3
1.3
1.2
1.2
1.3
1.3
1.3
1.2
1.6
1.2
1.2
1.4
1.3
1.4
1.4
1.4
1.1
1.4
1.1
1.1
1.3
1.3
28.2
AVG
1.3
(sorry for the cramming, but that's just the way it cuts & pastes into here from Excel. JPG was only 1/2" long!)
The average difference is 1.3gn in the various verified load data. This is from 9, 38, & 45 charts.
TG is a much faster powder....#14 vs #31 according to Hodgdon charts.
Question is, can one use that ratio of ~1.3 as a good starting point for pistol loads that do NOT have TG data but do have U? I know this does not take into account CUP or other factors, but the load data for most pistol powders seems to be within a grain or so of each other anyway. In no way am I proposing anyone use this simple mathematical solution for MAX loads!
I am sure there are others out there that are pondering the same questions, what with the extreme regional scarcity of certain powders on the shelves.
Looking for a little input from those wiser than I in the venue of powder loads.
bangerjim