I don't normally like to resurrect threads from the dead, but in this case I have something useful to add. One of the reasons I got into the Grendel was for the ability to shoot the 144 Lapua Scenar.
My first attempt at chronographing the 144s was on April 29, 2013 at an indoor range. Rifle used was an Alexander Arms upper from ca. 2007, midlength gas, 16" barrel. Speed was calculated using a Magnetospeed. Results were as follows:
Group 1
Wolf brass - once-fired
Lapua Scenar 144 FMJ
CCI 34
Accurate 2520
28.0 grains
COAL 2.250"
No crimp
Average velocity: 2265 fps
Extreme spread: 37 fps
Std. deviation: 15 fps
4 shots
Group 2
Wolf brass - once-fired
Lapua Scenar 144 FMJ
CCI 34
Accurate 2520
28.5 grains
COAL 2.250"
No crimp
Average velocity: 2307 fps
Extreme spread: 31 fps
Std. deviation: 14 fps
4 shots
Group 3
Lapua brass - virgin
Lapua Scenar 144 FMJ
CCI 41
Accurate 2520
29.0 grains
COAL 2.250"
No crimp
Average velocity: 2309 fps
Extreme spread: 31 fps
Std. deviation: 14 fps
4 shots
My second attempt at chronographing the 144s was today. Rifle used was the same Alexander Arms upper, 16" barrel, midlength gas. I believe the twist rate is 1:8. Chronographed using a Labradar. Results are as follows:
Group 1
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
27.2 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2191, 2184, 2188 fps
Average velocity: 2188 fps
Extreme spread: 7 fps
Standard deviation: 4 fps
3 shots
Group 2
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
27.5 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2223, 2214, 2232 fps
Average velocity: 2223 fps
Extreme spread: 18 fps
Standard deviation: 9 fps
3 shots
Group 3
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
27.8 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2261, 2262, 2279 fps
Average velocity: 2267 fps
Extreme spread: 18 fps
Standard deviation: 10 fps
3 shots
Group 4
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
28.1 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2270, 2263, 2263 fps
Average velocity: 2265 fps
Extreme spread: 7 fps
Standard deviation: 4 fps
3 shots
Group 5
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
28.4 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2277, 2277, 2280 fps
Average velocity: 2278 fps
Extreme spread: 3 fps
Standard deviation: 1.7 fps
3 shots
Group 6
Lapua brass
Lapua Scenar 144 FMJ
CCI 41
28.7 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2306, 2301, 2302 fps
Average velocity: 2303 fps
Extreme spread: 5 fps
Standard deviation: 2.6 fps
3 shots
I had one more group loaded with 29.0 grains ready to go, as that is the max load in Alexander Arms' load data. But because I was already starting to see light ejector swipes at 28.4 and 28.7 I decided to forgo it, especially since I already had the data from 9 years ago. 28.4 grains was the most accurate of the loads, so I think I'll search around that 28-28.5 grain range to find what the most accurate load could be.
ETA: In 2013 I was running a carbine buffer tube, spring, and buffer combo. And I don't remember checking the brass for ejector swipes afterward, but I do remember seeing some brass after the fact from other loads with heavy swipes so I suspected the gun was overgassed. Today I was running an A5 buffer system with the VLTOR A5-3 buffer.
I'm in the middle of building another 6.5 upper with an adjustable gas block, so I hope to test some of these loads soon on that upper to see whether this is a gas issue, a pressure issue, or merely a strong ejector spring. Primers looked the same at 28.7 as they did at 27.2.
My first attempt at chronographing the 144s was on April 29, 2013 at an indoor range. Rifle used was an Alexander Arms upper from ca. 2007, midlength gas, 16" barrel. Speed was calculated using a Magnetospeed. Results were as follows:
Group 1
Wolf brass - once-fired
Lapua Scenar 144 FMJ
CCI 34
Accurate 2520
28.0 grains
COAL 2.250"
No crimp
Average velocity: 2265 fps
Extreme spread: 37 fps
Std. deviation: 15 fps
4 shots
Group 2
Wolf brass - once-fired
Lapua Scenar 144 FMJ
CCI 34
Accurate 2520
28.5 grains
COAL 2.250"
No crimp
Average velocity: 2307 fps
Extreme spread: 31 fps
Std. deviation: 14 fps
4 shots
Group 3
Lapua brass - virgin
Lapua Scenar 144 FMJ
CCI 41
Accurate 2520
29.0 grains
COAL 2.250"
No crimp
Average velocity: 2309 fps
Extreme spread: 31 fps
Std. deviation: 14 fps
4 shots
My second attempt at chronographing the 144s was today. Rifle used was the same Alexander Arms upper, 16" barrel, midlength gas. I believe the twist rate is 1:8. Chronographed using a Labradar. Results are as follows:
Group 1
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
27.2 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2191, 2184, 2188 fps
Average velocity: 2188 fps
Extreme spread: 7 fps
Standard deviation: 4 fps
3 shots
Group 2
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
27.5 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2223, 2214, 2232 fps
Average velocity: 2223 fps
Extreme spread: 18 fps
Standard deviation: 9 fps
3 shots
Group 3
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
27.8 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2261, 2262, 2279 fps
Average velocity: 2267 fps
Extreme spread: 18 fps
Standard deviation: 10 fps
3 shots
Group 4
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
28.1 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2270, 2263, 2263 fps
Average velocity: 2265 fps
Extreme spread: 7 fps
Standard deviation: 4 fps
3 shots
Group 5
Lapua brass - once-fired
Lapua Scenar 144 FMJ
CCI 41
28.4 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2277, 2277, 2280 fps
Average velocity: 2278 fps
Extreme spread: 3 fps
Standard deviation: 1.7 fps
3 shots
Group 6
Lapua brass
Lapua Scenar 144 FMJ
CCI 41
28.7 grains Accurate 2520
COAL 2.250"
Crimped with Lee FCD
2306, 2301, 2302 fps
Average velocity: 2303 fps
Extreme spread: 5 fps
Standard deviation: 2.6 fps
3 shots
I had one more group loaded with 29.0 grains ready to go, as that is the max load in Alexander Arms' load data. But because I was already starting to see light ejector swipes at 28.4 and 28.7 I decided to forgo it, especially since I already had the data from 9 years ago. 28.4 grains was the most accurate of the loads, so I think I'll search around that 28-28.5 grain range to find what the most accurate load could be.
ETA: In 2013 I was running a carbine buffer tube, spring, and buffer combo. And I don't remember checking the brass for ejector swipes afterward, but I do remember seeing some brass after the fact from other loads with heavy swipes so I suspected the gun was overgassed. Today I was running an A5 buffer system with the VLTOR A5-3 buffer.
I'm in the middle of building another 6.5 upper with an adjustable gas block, so I hope to test some of these loads soon on that upper to see whether this is a gas issue, a pressure issue, or merely a strong ejector spring. Primers looked the same at 28.7 as they did at 27.2.