I've had some very good results using Quickload to work out optimal loads for my .308 rifles with 155, 175 and 185 bullets. I'm now trying to get 230s working in my 32" 10-twist barrel but things aren't going to plan...
I'm using Berger 230 Hybrids in Lapua brass with Reloder 17. The OAL is around 3.22" (barrel has been chambered specifically for the heavy Bergers).
A couple of days ago I tried loads from 41.6gn to 45.5gn of R-17 and every shot was chrono'd. When I plugged the results into Quickload and adjusted the Ba variable to match the measured MV of one of the loads, I find that when I then change the charge weight to match one of the tested loads, the predicted MV is way out. I've tried tweaking bullet weight and weighting factor but I can't find any way to make the velocities tie up with my test data across the range of loads I tested.
This means I can't currently use it to work out loads based on the OBT method.
Does anyone know why this is going wrong and whether there's something else I should be doing to get this to work with this bullet/powder combination?
I've double checked the bullet measurements and case capacity to make sure they're spot on.
Here's an example of what I'm getting:
Load Actual MV QL MV with Ba changed to match 41.6 load
41.6 2257 2257
43 2355 2328
44 2430 2379
45 2500 2429
If I correct the Ba to match the 45gn load I get this:
Load Actual MV QL MV with Ba changed to match 45 load
41.6 2257 2337
43 2355 2405
44 2430 2453
45 2500 2500
I don't know what to try next, other than to go back to ladder tests and group tests to try and find the nodes.
I'm using Berger 230 Hybrids in Lapua brass with Reloder 17. The OAL is around 3.22" (barrel has been chambered specifically for the heavy Bergers).
A couple of days ago I tried loads from 41.6gn to 45.5gn of R-17 and every shot was chrono'd. When I plugged the results into Quickload and adjusted the Ba variable to match the measured MV of one of the loads, I find that when I then change the charge weight to match one of the tested loads, the predicted MV is way out. I've tried tweaking bullet weight and weighting factor but I can't find any way to make the velocities tie up with my test data across the range of loads I tested.
This means I can't currently use it to work out loads based on the OBT method.
Does anyone know why this is going wrong and whether there's something else I should be doing to get this to work with this bullet/powder combination?
I've double checked the bullet measurements and case capacity to make sure they're spot on.
Here's an example of what I'm getting:
Load Actual MV QL MV with Ba changed to match 41.6 load
41.6 2257 2257
43 2355 2328
44 2430 2379
45 2500 2429
If I correct the Ba to match the 45gn load I get this:
Load Actual MV QL MV with Ba changed to match 45 load
41.6 2257 2337
43 2355 2405
44 2430 2453
45 2500 2500
I don't know what to try next, other than to go back to ladder tests and group tests to try and find the nodes.