A follow up and conclusion to this thread: http://www.snipershide.com/shooting...first-ocw-ditched-lead-sled-good-results.html
Test platform:
Long Rifles Inc. built Surgeon 591 - 26" Bartlein 5R M24 Contout - 1-11" twist - Manners T4A stock - Nightforce 5.5-22x56 - Jewell Trigger
Test Load -
Lapua Brass - minimal prep (primer pockets squared, trimmed / chamfered / deburred on Giraud), neck sized with Redding Comp. bushing die, and full length sized with Redding body die to .002" shoulder bump - Varget - 175 Sierra Match Kings - FGMM Primers.
I made it out yesterday to do the confirmation of the node I discovered during my last OCW test. I had a nice wide node from 43.4 grains all the way to 44.6 - all with similar POI and sub .5 MOA groups at 100 yards so the next step was to confirm this node at long range. 500 is about the best I can do without driving really far so that is what I stuck with. I wanted to do a bracket test with different points in the node so chose three points to test - 43.6, 43.7 and 43.8 grains of varget and loaded 2 each of these. From here I loaded 2 rounds @ 1% above each of these points and 2 rounds @ 1% below these points. What I ended up with was this:
Test #1
43.2 x 2
43.6 x 2
44 x 2
Test #2
43.3 x 2
43.7 x 2
44.1 x 2
Test #3
43.4 x 2
43.8 x 2
44.2 x 2
I pulled DOPE from JBM ballistics with inputs for 2700 FPS (average velocity for this charge range) and dialed 10.5 MOA from my 100 yard zero. I shot each test and its own target "semi round-robbin" style ie: the low charge weight, middle charge weight next, high charge weight, and repeat for second set of rounds. Each target received 6 rounds total.
My lasered range was 489 yards - wind was 2-3 mph and shifting from my 7 o'clock to my 8 o'clock. I was rushed for time as the sun had already set but I still had decent vis. of the targets.
The results.
Test 1:
Test 2:
Test 3: (smallest group - measured 3.972" C To C)
This last target was shot very quickly just before it got too dark to shoot - the wind had increased to approx 5mph and increased its angle ( 8 o'clock, left to right )
All of these rounds were the 43.8 charge - (vertical measures 1.865" horizontal measures 3.96")
My conclusion - I like the 43.8 node group (test #3) as is had not only the smallest group center to center, but also the least vertical dispersion. I will be sticking with this charge weight and load recipe and playing around with the seating depth a bit to see if I can get it dialed even tighter.
Questions, comments or criticisms appreciated -
Test platform:
Long Rifles Inc. built Surgeon 591 - 26" Bartlein 5R M24 Contout - 1-11" twist - Manners T4A stock - Nightforce 5.5-22x56 - Jewell Trigger
Test Load -
Lapua Brass - minimal prep (primer pockets squared, trimmed / chamfered / deburred on Giraud), neck sized with Redding Comp. bushing die, and full length sized with Redding body die to .002" shoulder bump - Varget - 175 Sierra Match Kings - FGMM Primers.
I made it out yesterday to do the confirmation of the node I discovered during my last OCW test. I had a nice wide node from 43.4 grains all the way to 44.6 - all with similar POI and sub .5 MOA groups at 100 yards so the next step was to confirm this node at long range. 500 is about the best I can do without driving really far so that is what I stuck with. I wanted to do a bracket test with different points in the node so chose three points to test - 43.6, 43.7 and 43.8 grains of varget and loaded 2 each of these. From here I loaded 2 rounds @ 1% above each of these points and 2 rounds @ 1% below these points. What I ended up with was this:
Test #1
43.2 x 2
43.6 x 2
44 x 2
Test #2
43.3 x 2
43.7 x 2
44.1 x 2
Test #3
43.4 x 2
43.8 x 2
44.2 x 2
I pulled DOPE from JBM ballistics with inputs for 2700 FPS (average velocity for this charge range) and dialed 10.5 MOA from my 100 yard zero. I shot each test and its own target "semi round-robbin" style ie: the low charge weight, middle charge weight next, high charge weight, and repeat for second set of rounds. Each target received 6 rounds total.
My lasered range was 489 yards - wind was 2-3 mph and shifting from my 7 o'clock to my 8 o'clock. I was rushed for time as the sun had already set but I still had decent vis. of the targets.
The results.
Test 1:
Test 2:
Test 3: (smallest group - measured 3.972" C To C)
This last target was shot very quickly just before it got too dark to shoot - the wind had increased to approx 5mph and increased its angle ( 8 o'clock, left to right )
All of these rounds were the 43.8 charge - (vertical measures 1.865" horizontal measures 3.96")
My conclusion - I like the 43.8 node group (test #3) as is had not only the smallest group center to center, but also the least vertical dispersion. I will be sticking with this charge weight and load recipe and playing around with the seating depth a bit to see if I can get it dialed even tighter.
Questions, comments or criticisms appreciated -
