finally got to range after a 3 month hiatus. brought the chrony along to get some cold-ish weather data on rounds that shoot lights out during the summer months. unfortunately i dont have data during the warm months so i cant compare yet but perhaps someone with a similar setup can extrapolate.
gun is stock rem 700 308 AAC-SD with SWFA SS 5-20
loads
44.1 IMR 4064 and 47.2 CFE 223 behind 178 AMAX, federal 210GM and 7x fired necked only win brass loaded LONG .02 off lands
the numbers:
40-47 F with 50% humidity. 30.05 baro according to weather channel. no, i dont have a do it all pocket weather station.
the 4064 loads started off opening up badly but tightened up the hotter the barrel got. numbers look like this over 2 10 shot strings. grouped the same as they did in the summer
Highs: 2515,2510 ES: 46,46
Lows: 2469,2464 SD: 15,18
AVG: 2494, 2492
the CFE 223 has me miffed. they are tight during the summer but looked bad today. normal .6 load was 1.5 moa today. 2 10 shot strings.
Highs: 2574, 2564 ES: 78, 77
Lows: 2496, 2487 SD: 22, 27
AVG: 2537, 2534
now, my thoughts. i had high hopes for the CFE. promising higher velocities at the expense of temp stability over varget. during the summer it seems to do well but i dont have concrete data yet. the ES is pretty big though and im wondering where the difference is coming from. is this temp instability or perhaps my scale was off a bit? is this just a property of the powder regardless of temperature?
if i can get groups to tighten back up is the added 50 fps worth any downside? not sure if im wasting time perusing negligible speed.
lastly to ensure it isn't my poor shooting, i will be repeating the test next month in similar conditions with another known shooter.
ready, set, discuss!
gun is stock rem 700 308 AAC-SD with SWFA SS 5-20
loads
44.1 IMR 4064 and 47.2 CFE 223 behind 178 AMAX, federal 210GM and 7x fired necked only win brass loaded LONG .02 off lands
the numbers:
40-47 F with 50% humidity. 30.05 baro according to weather channel. no, i dont have a do it all pocket weather station.
the 4064 loads started off opening up badly but tightened up the hotter the barrel got. numbers look like this over 2 10 shot strings. grouped the same as they did in the summer
Highs: 2515,2510 ES: 46,46
Lows: 2469,2464 SD: 15,18
AVG: 2494, 2492
the CFE 223 has me miffed. they are tight during the summer but looked bad today. normal .6 load was 1.5 moa today. 2 10 shot strings.
Highs: 2574, 2564 ES: 78, 77
Lows: 2496, 2487 SD: 22, 27
AVG: 2537, 2534
now, my thoughts. i had high hopes for the CFE. promising higher velocities at the expense of temp stability over varget. during the summer it seems to do well but i dont have concrete data yet. the ES is pretty big though and im wondering where the difference is coming from. is this temp instability or perhaps my scale was off a bit? is this just a property of the powder regardless of temperature?
if i can get groups to tighten back up is the added 50 fps worth any downside? not sure if im wasting time perusing negligible speed.
lastly to ensure it isn't my poor shooting, i will be repeating the test next month in similar conditions with another known shooter.
ready, set, discuss!
