Load development.....opinions??

[willyqbc]

So I am always curious as to how others do their load development, and had some results at the range today that opens the door to some potentially interesting discussion.

rifle is a savage lightweight hunter in 7-08 19" barrel
120 nosler ballistic tip over Varget
brass has not been fired in this rifle and was annealed,full length sized and trimmed
initial work up loads of 42.5 - 45.5 grns and shot them at 110yds

42.5 - 2759, 2808, 2798fps 1.425"
43.0 - 2826, 2834, 2819fps 1.315"
43.5 - 2857, 2835, 2846fps 1.132"
44.0 - 2899, 2898, 2922fps 1.202"
44.5 - 2911, 2907, 2918fps 0.657"
45.0 - 2947, 2963, 2957fps 0.363"
45.5 - 2980, 3013, 2977fps 1.580"

Now, at this point we look at the data and decide where to go next? for the sake of argument, lets say we are developing a 500 yd hunting load.

44.0 and 44.5 show a total standard deviation of 9.75 and an extreme spread of 24 fps, but point of impact was approximately 3/4" different

44.5 and 45.0 show a total standard deviation of 24.7 and an extreme spread of 56 fps, point of impact was identical. 45.0 group would have landed inside the 44.5 group.

So moving out further for testing, do you go after the 44.0 - 44.5 range with the very consistant velocity

OR

do you chase the 44.5 - 45 range with the tighter groups and consistant point of impact?

Seeing as I have allready loaded tomorrows rounds, I know which one I'm chasing

.....just curious how you all would proceed in your load development??

Chris

 

[L.Sherm]

44.5 and 45.0

 

[ShtrRdy]

44.5 - 45.0
I go off of the groups shrinking and ending up in the same location. The sweet spot might be a powder charge in between those two values.

 

[Jud96]

I would try 44.3, 44.6, and 44.8

 

[Deleted member 107796]

45.0 without question, IMO, especially for long range hunting with that nice velocity.

 

[willyqbc]

okay, by and large I agree with the advice above given the info I provided, I had loaded 5 shot groups of 44.4,44.6,44.8 and 45.0 to shoot tomorrow at 330 yds.

However, I'll fill in some more info....temp today was -5c (23F), round has the potential to be shot in temps from -30c (-22F) up to +25c (77F). Would this info change opinions any? How bout if I said it was to be shot at 1000yds? would that change opinions on what direction to go with this load development?

what say you?
Chris

 

[Jud96]

okay, by and large I agree with the advice above given the info I provided, I had loaded 5 shot groups of 44.4,44.6,44.8 and 45.0 to shoot tomorrow at 330 yds.

However, I'll fill in some more info....temp today was -5c (23F), round has the potential to be shot in temps from -30c (-22F) up to +25c (77F). Would this info change opinions any? How bout if I said it was to be shot at 1000yds? would that change opinions on what direction to go with this load development?

what say you?
Chris

Varget is a very temp stable powder, but it's not 100% perfect, just like everything. I would make sure you settle on a load that doesn't show any signs of pressure in the cold weather. I would also test beyond 100 yards if that's possible. You want a load with a low ES and the load with the least amount of vertical stringing for 1000yds. A load that shoots 1/2 MOA at 100 but has an ES under 20 will be more consistent and shoot better at 1000 than a load that shoots 1/4 MOA with an ES in the 30s or higher.

 

[jjmp]

When varget came out a high power shooter told me it likes to run throttled up , THIS info is NOT for newbie reloads ,only very Sage Experienced reloaders with yrs n yrs under their belt thks .

 

[DUSTY NOGGIN]

there is a more stable velocity plateau between 44&45 , id focus there

then seating , you see if you can bring that group down to the lower sd range

its awesome to see three lines in intersecting to show a more realistic trend. when i do the loads first velocity test, i normally just do the one shot of each 42.5, 42.7 42.9 43.1 43.3 43.5 ect... up to max .

same amount of shots but your three shot groups helps see the variation at each point that i miss , plus gives an idea of group size ...

what speedometer are you using ??

 

[willyqbc]

what speedometer are you using ??

Using a labradar. I like the chart Dusty...what app/program are you using to generate that? Havent been able to find anything that wasnt a PITA to work with.

Thanks for all the replies folks!

I think all of the above is great info, and illustrates a bit that the intended use can drastically change the way we approach load development. If this were intended to be used at 1000 yds I think i would be working with the velocity "flat spot" between 44.0 and 44.5 and try and fine tune the group size with seating depth.

In this particular instance, the load will be used for coyote/wolf all year round out to probably 400 yd max. So for this, the consistant point of impact across a powder range coupled with good group size makes the most sense. given current temps here and knowing it will be used in substantially warmer and cooler weather something around 44.6 would be ideal as it would allow some temp induced velocity change up and down without losing the same POI.

Off to the range shortly to test 44.4 up to 45.0 in .2 increments at a further distance!

Chris

 

[cperazza]

Based on your initial results:

44.5 and 45.0 show a total standard deviation of 24.7 and an extreme spread of 56 fps, point of impact was identical. 45.0 group would have landed inside the 44.5 group.

I would try 44.5, 44.8, 45.0, 45.2. most likely your accuracy node will be 44.8, since any small deviation in powder charge will keep you within the same point of impact. My 2¢s

 

[willyqbc]

NOV 25/18 0 DEG C 220 YDS

44.4 – 2917, 2917, 2912, 2919, 2899, 2917, 2913 2.685"
44.6 – 2947, 2925, 2924, 2927, 2934 2.113"
44.8 – 2960, 2952, 2954, 2926, 2949 2.446"
45.0 – 2957, 2948, 2966, 2954, 2954 1.779"

inconsistant, gusty right to left 15 mph wind may have opened these groups up. All POI the same
45.0 SD 6.5 ES 19 AVG – 2956 FPS (8 shots)

Need to go above 45.0 to see if the POI remains the same....if it will hit in the same spot up to 45.2 or 45.4, I would be happy with that, would give me close to a grain of variation without a poi shift. If POI starts to shift at 45.2, prolly back down to 44.8 and play with seating depth there.

 

[Mikecr]

brass has not been fired in this rifle and was annealed,full length sized and trimmed

If this was with brass that has not been fireformed to stable capacity & chamber fit, then you have this to go before powder development begins.
Until then, it's a good time to do Berger's recommended full bullet seating testing.

 

[Buzzsaw]

Just my opinion but I think what your doing is a waste of components. Yes, Its fun for some.
Most ladder tests are run by folks looking for a ultra long range load, the PRS guys who aren't pro's and shoot free factory ammo, etc.
No offense but your rifle is a good "hunting" rifle to 300ish yards. Find a load which groups the best. Test it at 300 yards, Be done with it. I doubt you will get any true half MOA groups with the Savage, or many other factory $500 rifles.

If a MACHINE rest were used in ladder testing it would make sense but as long as there is a human shooting, there will never be conclusive data.

like I say, just my opinion. reloaders obsess over these ladder test, I just dont get it.

But I'm now obsessing over load data for Hammer Bullets, so I'm goofy