The rifle is a defiance tenacity with a bartlein 24” 1:7.5tw carbon wrapped barrel that was built by Marc at Spartan Precision rifles. Shoots factory hornady at 1/2moa with a es of around 20fps so I am definitely happy with it so far. I live in Comifornia so I have to hunt with copper and started load development with Barnes 127lrx and H1000.
The rifle had 155 rounds down it so far till today and I loaded up 4 strings from 57.7 to 59.5gr. Two identical strings with cci magnum primers and two identical with fed 210M primers. The far left column is the first ladder on a cold barrel, followed by column 3 with 210m, then column 2 and lastly column 4. These 4 strings were all within about a 30min span so the barrel got pretty hot. Seems there was a velocity shift from the first column to the other three. Not sure if this is cause of the solid copper projectiles as I have had issues with copper in the past after shooting jacketed bullets or if it has to do with the way the barrel handles heat but the es in the other three columns is definitely a lot better after the barrel was warm and it didn’t open up a bunch on the last one when the barrel was hot either so I am not sure what to make of it all. 59.3 and 59.5 are slightly compressed so I don’t plan to go up any even though I would like more speed. Looking at the numbers I think I will load up 5 of 59.2 and 5 of 59.4 and see what it looks like unless someone is seeing something I am not it seems around 59.3 is where my node is.
This is all on once fired hornady brass, 2 thou shoulder bump, about 2 thou neck tension with a Redding type s and a SAC .290 bushing. Powder is dropped .1gr low from a Frankfort arsenal intellidropper and then trickled up to the target charge. Everything was seated 50 thou off.
The rifle had 155 rounds down it so far till today and I loaded up 4 strings from 57.7 to 59.5gr. Two identical strings with cci magnum primers and two identical with fed 210M primers. The far left column is the first ladder on a cold barrel, followed by column 3 with 210m, then column 2 and lastly column 4. These 4 strings were all within about a 30min span so the barrel got pretty hot. Seems there was a velocity shift from the first column to the other three. Not sure if this is cause of the solid copper projectiles as I have had issues with copper in the past after shooting jacketed bullets or if it has to do with the way the barrel handles heat but the es in the other three columns is definitely a lot better after the barrel was warm and it didn’t open up a bunch on the last one when the barrel was hot either so I am not sure what to make of it all. 59.3 and 59.5 are slightly compressed so I don’t plan to go up any even though I would like more speed. Looking at the numbers I think I will load up 5 of 59.2 and 5 of 59.4 and see what it looks like unless someone is seeing something I am not it seems around 59.3 is where my node is.
This is all on once fired hornady brass, 2 thou shoulder bump, about 2 thou neck tension with a Redding type s and a SAC .290 bushing. Powder is dropped .1gr low from a Frankfort arsenal intellidropper and then trickled up to the target charge. Everything was seated 50 thou off.
