Hey, dudes. Guess I should call this load development testing, not a ladder test, but you get the idea.
Just started reloading. Took my new bolt gun out today to test 10 different loads. Here is the rifle and load info:
Savage 10T .308 Win, 24" bull barrel, 1-10" twist, 5R rifling
Only 60 rounds down the tube of cheap plinking ammo prior to today's test
Hornady 168 BTHP Match
PMC Brass (switching to something better soon)
IMR 4064
CCI-200 large rifle primers
Full length resized, cut to 2.005, COAL was 2.800"
Temp was 31ºF.
Reloads were from 42.0 up to 43.8 in 0.2 grain increments.
Below are the pics.
Here are my measurements. I am pretty sure a few groups had a single flyer, but I counted them anyway. Whatever.
42.0 - 0.75"
42.2 - 1.19"
42.4 - 0.88"
42.6 - 0.81"
42.8 - 0.50"
43.0 - 1.00"
43.2 - 0.88"
43.4 - 0.88"
43.6 - 1.25"
43.8 - 0.88"
A few caveats that I am aware of: Rifle is new and not fully broken in. I am new to the rifle and still mastering it. Pressure (and hence groups) may change once I switch brand of cases. And I should be shooting groups at 300, too.
It's obvious that the 42.8, or thereabouts, was a good low node. But a lot of the other groups seemed pretty good, and my instincts told me that my groups were starting to tighten up again at the top of the ladder range (43.8). I only loaded to 43.8 grains today because it's my first time reloading and I didn't want to push it. I am interested in shooting out to 1000 eventually, so I am not interested in low-velocity, bunny-fart loads. So, as much as I loved that 0.5" group at 42.8 grains, the velocity probably sucks, probably somewhere in the 2550-2600 range. I would like to push a 168 grain pill to about 2700-2750 fps, which shouldn't be an issue with a 24" barrel. So I am looking for a high node, hopefully in the 43.5-44.5 range of powder. I don't want to push max loads at 45+ grains. I am not interested in wearing out my brass or rifle prematurely ... or my shoulder.
At 43.8 grains, I saw zero pressure signs on my cases. There was a noticeable increase in recoil and pressure starting at 43.6 grains. It was a like a light switch. 43.4 grains was nothing. 43.6 grains started to kick a bit. But still, zero pressure signs on the cases. So I think I am safe to carefully push up to the mid-44 grain range.
But the problem I see is that, with the exception of a few 1.0"+ groups, a lot of these groups were decent, in the 0.8" range. My next time out I would like to explore the 43.5 range up to about 44.3 or so in 0.1 grain increments and really get this narrowed down to a good load. I have a friend who can chrono it for me when I find a load, to confirm that velocity is up to par for what I want to do.
But am I missing something with regards to analyzing these groups? Should I be paying more attention to vertical dispersion or both vertical and horizontal?
Thanks for any help.
Just started reloading. Took my new bolt gun out today to test 10 different loads. Here is the rifle and load info:
Savage 10T .308 Win, 24" bull barrel, 1-10" twist, 5R rifling
Only 60 rounds down the tube of cheap plinking ammo prior to today's test
Hornady 168 BTHP Match
PMC Brass (switching to something better soon)
IMR 4064
CCI-200 large rifle primers
Full length resized, cut to 2.005, COAL was 2.800"
Temp was 31ºF.
Reloads were from 42.0 up to 43.8 in 0.2 grain increments.
Below are the pics.
Here are my measurements. I am pretty sure a few groups had a single flyer, but I counted them anyway. Whatever.
42.0 - 0.75"
42.2 - 1.19"
42.4 - 0.88"
42.6 - 0.81"
42.8 - 0.50"
43.0 - 1.00"
43.2 - 0.88"
43.4 - 0.88"
43.6 - 1.25"
43.8 - 0.88"
A few caveats that I am aware of: Rifle is new and not fully broken in. I am new to the rifle and still mastering it. Pressure (and hence groups) may change once I switch brand of cases. And I should be shooting groups at 300, too.
It's obvious that the 42.8, or thereabouts, was a good low node. But a lot of the other groups seemed pretty good, and my instincts told me that my groups were starting to tighten up again at the top of the ladder range (43.8). I only loaded to 43.8 grains today because it's my first time reloading and I didn't want to push it. I am interested in shooting out to 1000 eventually, so I am not interested in low-velocity, bunny-fart loads. So, as much as I loved that 0.5" group at 42.8 grains, the velocity probably sucks, probably somewhere in the 2550-2600 range. I would like to push a 168 grain pill to about 2700-2750 fps, which shouldn't be an issue with a 24" barrel. So I am looking for a high node, hopefully in the 43.5-44.5 range of powder. I don't want to push max loads at 45+ grains. I am not interested in wearing out my brass or rifle prematurely ... or my shoulder.
At 43.8 grains, I saw zero pressure signs on my cases. There was a noticeable increase in recoil and pressure starting at 43.6 grains. It was a like a light switch. 43.4 grains was nothing. 43.6 grains started to kick a bit. But still, zero pressure signs on the cases. So I think I am safe to carefully push up to the mid-44 grain range.
But the problem I see is that, with the exception of a few 1.0"+ groups, a lot of these groups were decent, in the 0.8" range. My next time out I would like to explore the 43.5 range up to about 44.3 or so in 0.1 grain increments and really get this narrowed down to a good load. I have a friend who can chrono it for me when I find a load, to confirm that velocity is up to par for what I want to do.
But am I missing something with regards to analyzing these groups? Should I be paying more attention to vertical dispersion or both vertical and horizontal?
Thanks for any help.
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