Nemo288
Member
I scored some of the Maxam CSB-1 in the hope it could replace Universal/Unique in my target loads.
I finally got to shoot my first test box.
The equipment:
A ProChrono digital with Caldwell infrared light bar for indoor use.
A 30 year old Ruger Redhawk 7.5" and a S&W 629-2 4" ported.
The load:
Brand new Starline nickel 44 magnum brass.
WLP primers.
X-Treme 240 grain Plated Flat Point bullet loaded to 1.563" COAL
Light Pro Crimp in cannelure
6-9.5 grains CSB-1 (I chickened out at the last moment on loading 10)
The Data:
..........................4" 629-2....................................7.5" Redhawk
Grains..........FPS.........SD.........CE....................FPS..........SD.............CE
6.................670........24...........4533................747..........17..............454
7.................829.........7............4562................870..........20..............456
8.................897........10...........4575................985...........6...............4576
9 ................977........14...........4587...............1066..........16..............4586
9.5.............1024........16...........4592...............1096..........10..............459
Notes:
CE is case diameter at its largest at the pressure bulge ahead of the rim. This is NOT case head expansion.
By the last 2 loads it is approaching maximum allowed by the chamber and is starting to move downward towards the rim.
In a given lot of brass you can get a feel for the pressure regime by the "profile" of the bulge.
If it is a steep shelf you are in trouble.
I would load 10 grains but that would be it. The cases looked fine and were not anywhere near the look of a "full" load.
The performance is in line with Universal and Unique. 10 grains is the accepted standard maximum for Universal under a 240 either lead or copper.
A regression of the load data shows a best fit using a logarithmic curve and predicts a 10 grain velocity of 1145 in the Redhawk.
Again this is in the ballpark compared to published data.
To show the futility of using Standard Deviation with small data sets (5 in this case), the best target was turned in by 7 grains in the Redhawk which had the 2nd worst SD.
In retrospect, I should have used a stronger bullet as I started to get some keyholing with the top 2 loads.
I have also seen this phenomenon when driving the Speer GDHP (also a plated bullet) too fast.
I have loaded some side by side comparison rounds with CSB-1 and Universal.
When I get them shot I will append the results here.
I have not had a working optical chronograph for many years so most of my Universal target loads were developed using holes in paper.
Consequently I don't have all the data I would wish for to make better comparisons here.
===
Nemo
I finally got to shoot my first test box.
The equipment:
A ProChrono digital with Caldwell infrared light bar for indoor use.
A 30 year old Ruger Redhawk 7.5" and a S&W 629-2 4" ported.
The load:
Brand new Starline nickel 44 magnum brass.
WLP primers.
X-Treme 240 grain Plated Flat Point bullet loaded to 1.563" COAL
Light Pro Crimp in cannelure
6-9.5 grains CSB-1 (I chickened out at the last moment on loading 10)
The Data:
..........................4" 629-2....................................7.5" Redhawk
Grains..........FPS.........SD.........CE....................FPS..........SD.............CE
6.................670........24...........4533................747..........17..............454
7.................829.........7............4562................870..........20..............456
8.................897........10...........4575................985...........6...............4576
9 ................977........14...........4587...............1066..........16..............4586
9.5.............1024........16...........4592...............1096..........10..............459
Notes:
CE is case diameter at its largest at the pressure bulge ahead of the rim. This is NOT case head expansion.
By the last 2 loads it is approaching maximum allowed by the chamber and is starting to move downward towards the rim.
In a given lot of brass you can get a feel for the pressure regime by the "profile" of the bulge.
If it is a steep shelf you are in trouble.
I would load 10 grains but that would be it. The cases looked fine and were not anywhere near the look of a "full" load.
The performance is in line with Universal and Unique. 10 grains is the accepted standard maximum for Universal under a 240 either lead or copper.
A regression of the load data shows a best fit using a logarithmic curve and predicts a 10 grain velocity of 1145 in the Redhawk.
Again this is in the ballpark compared to published data.
To show the futility of using Standard Deviation with small data sets (5 in this case), the best target was turned in by 7 grains in the Redhawk which had the 2nd worst SD.
In retrospect, I should have used a stronger bullet as I started to get some keyholing with the top 2 loads.
I have also seen this phenomenon when driving the Speer GDHP (also a plated bullet) too fast.
I have loaded some side by side comparison rounds with CSB-1 and Universal.
When I get them shot I will append the results here.
I have not had a working optical chronograph for many years so most of my Universal target loads were developed using holes in paper.
Consequently I don't have all the data I would wish for to make better comparisons here.
===
Nemo