Would appreciate your help with interpreting some ladder test data
I made my first attempt at doing a load ladder test and generated some data with my 12FV 223 using a few different bullets and H322 powder.
Powder charges were trickled and weighed on my trusty old RCBS 5-0-2 scale. I do question if this scale is adequate for doing this type of work.
All rounds were loaded in full length sized Starline brass trimmed to 1.750" and using Winchester primers.
Velocity measurements were taken with a Magnetospeed Sporter chronograph.
In both tests, shots 2 and 3 were lower in velocity than shot 1. What's up with this? I saw the same thing a week before in data that I eventually discarded due to the chrono bayonet loosening and changing position mid test. Interesting that it repeated itself.
My gut tells me that this data is questionable.
Would anyone care to interpret the data and provide comments/opinions? I would appreciate any thoughts you may have on this.
Hornady 53 grain V-Max loaded at 2.310" COL (0.040 off the lands)
Gr H322 |
FPS |
22.2 |
3092 |
22.4 |
3037 |
22.6 |
3046 |
22.8 |
3131 |
23.0 |
3174 |
23.2 |
3171 |
23.4 |
3173 |
23.6 |
3272 |
23.8 |
3282 |
24.0 |
3317 |
Sierra Match King 52 gr BTHP loaded at 2.210" COL (0.020 off the lands)
Gr H322 |
FPS |
22.5 |
3128 |
22.7 |
3115 |
22.9 |
3120 |
23.1 |
3198 |
23.3 |
3221 |
23.5 |
3261 |
23.7 |
3305 |
23.9 |
3330 |
24.1 |
3353 |
24.3 |
3378 |