30 sherman magnum

So my first run of the 250g A-tips with N570 got me this:

80g, Fed 215, ADG 5th firing, BTO 2.827 and a col of 3.697 - 2825 fps

80.5g, Same components - 2839 fps

81g - 2871 fps

81.5g - 2865 fps

82g - 2893 fps

My barrel is a Benchmark #4, 9T at 26". The 81.5g flattened a primer slightly but other than that I had no pressure signs. I think I will stop at 82g and see how that groups. These were initial powder loads - one shot each. I used labradar for my chrono with a magneto speed for verification. The 2 units were 4 fps different so I will call that good as well. These are the loads that worked in my rifle. They may not work in yours.

Temp was 30 degrees at 4473 ft elevation.
 
So my first run of the 250g A-tips with N570 got me this:

80g, Fed 215, ADG 5th firing, BTO 2.827 and a col of 3.697 - 2825 fps

80.5g, Same components - 2839 fps

81g - 2871 fps

81.5g - 2865 fps

82g - 2893 fps

My barrel is a Benchmark #4, 9T at 26". The 81.5g flattened a primer slightly but other than that I had no pressure signs. I think I will stop at 82g and see how that groups. These were initial powder loads - one shot each. I used labradar for my chrono with a magneto speed for verification. The 2 units were 4 fps different so I will call that good as well. These are the loads that worked in my rifle. They may not work in yours.

Temp was 30 degrees at 4473 ft elevation.
I'm gonna shoot for this bullet for my long range steel. That's for Doing the work.
 
Today's results.
1x ADG brass
215m primers
250gr A-Tips
RL33
82.3gr: 2784
82.6gr 2812? Weird one
82.9gr 2760
83.2gr 2791
83.5gr 2815
83.8gr 2812
84.1gr 2824
84.4gr 2823
84.7gr 2851
85.0gr 2859
85.3gr 2875
85.6gr 2888
85.9gr 2868
86.2gr 2902
86.5gr 2903
86.8gr 2932
87.1gr 2923
87.4gr 2933
87.7gr 2960
88.0gr 2953
I never hit pressure and can go a little further if I wanted to. The cases were pretty full but nothing crazy.
I'm going to test between 86.8gr and 87.4gr.
20220213_161133.jpg
20220213_161143.jpg
20220213_161148.jpg
 
Last edited:
Today's results.
1x ADG brass
215m primers
250gr A-Tips
RL33
82.3gr: 2784
82.6gr 2812? Weird one
82.9gr 2760
83.2gr 2791
83.5gr 2815
83.8gr 2812
84.1gr 2824
84.4gr 2823
84.7gr 2851
85.0gr 2859
85.3gr 2875
85.6gr 2888
85.9gr 2868
86.2gr 2902
86.5gr 2903
86.8gr 2932
87.1gr 2923
87.4gr 2933
87.7gr 2960
88.0gr 2953
I never hit pressure and can go a little further if I wanted to. The cases were pretty full but nothing crazy.
I'm going to test between 86.8gr and 87.4gr.
View attachment 341018View attachment 341019View attachment 341020
Impressive
 
Man I may have to chase that load also.
I have a few boxes of those a tips sitting around.
Pretty impressive numbers with the 250s. Never imagined that 30SM would get to 3K. So much for hearing the guys say that Sherman's numbers are all way over pressured and exaggerated numbers. While I'm sure the 300PRC will serve me well, the 30SM definitely is a good step above it's performance.
 
Pretty impressive numbers with the 250s. Never imagined that 30SM would get to 3K. So much for hearing the guys say that Sherman's numbers are all way over pressured and exaggerated numbers. While I'm sure the 300PRC will serve me well, the 30SM definitely is a good step above it's performance.
I started out with a 28" M24 9 twist SS Proof barrel chambered in 300PRC. I was running it at 2943fps with 225gr ELDM's and RL26. Can't remember the exact powder charge. I had a chance to get a Straight Jacket Armory chambered 28" M24 8 twist Bartlein in 30 Sherman Magnum. I am running 225grELDM'S around 3020fps in a lower node. I have been extremely happy with the 30SM for accuracy and overall performance. Something to note, I am not chasing my top end nodes in hopes that it will help extend the life of my barrel and brass. I have been trying to run a few grains under max load.
Yesterday's results running the 250gr A-Tips and RL33 were good but I did not see pressure signs even at 88.0gr. I still might run it up higher yet to see where my max will be. I would imagine that I am close.
 
Pretty impressive numbers with the 250s. Never imagined that 30SM would get to 3K. So much for hearing the guys say that Sherman's numbers are all way over pressured and exaggerated numbers. While I'm sure the 300PRC will serve me well, the 30SM definitely is a good step above it's performance.
The truth comes out eventually. I just need to let clients do it instead of getting in the fray! Its better for my blood pressure and also for my witness.
 
The truth comes out eventually. I just need to let clients do it instead of getting in the fray! Its better for my blood pressure and also for my witness.
@elkaholic you were on point when telling me 88-89 grains of RL33. Now I'm wishing I would have loaded up to 89gr of RL33.
All of your advice regarding the 30SM has been good.
 
Last edited:
Just so everyone knows. I run an off barrel mounted v3 magnetospeed for all velocity collection. When I dial in my load I do not like how the barrel mounted magnetospeed changes the point of aim and usually doubles the group size. No Bueno.
 

Attachments

  • 20210710_093138.jpg
    20210710_093138.jpg
    1.8 MB · Views: 80
Thank you and you're welcome!
Yes thank you. I am really enjoying the 30SM. I think it pushes the 300Norma mag and or a 338LM out of the picture for me. I am surprised more people aren't running it.
Running the numbers yesterday with the 250gr A-Tips at 2935fps muzzle velocity did not go transonic until 2100 yards. Freaking awesome.
 

Recent Posts

Top