I just recently finished all of my load data for my 20" Noveske barreled AR .308 Found Here and I am completely puzzled. I went shooting the other day and was blown away by the Sierra program, but in a bad way. I've been chatting with a good friend of mine, who basically taught me everything I know about LR shooting, and we think it could possibly be my loading. However I wanted to get some opinions if we are both missing something possibly.
1) All my loading procedure's are the same. The brass, powder, primers, seating depth, brass prep, etc are all the same. The only thing that changed was I opened a new box of 168 SMK's from a new lot, but can it really create that much of difference of impact at only 300 yards? The BC could be slightly different due to a new die, but can it create that much of difference in impact?
2) I weighed all my throws to make sure they come out to 42.1.
3) All COAL were the same at 2.775, in all IMI match brass, with FGMM primers, and IMR 4895 powder.
Firstly I confirmed my 100y zero with my CB shot (pulled it 1/4 inch left.. which by the way I'm seeing a pattern after logging my CB shots. All my CB shots are to the left anywhere from 1/4-1/2 inch). So after that I began confirming my real world drop data for Sierra's predicted drop. Sierra had a 5.3 MOA drop (16.5 inches), without adding in the temp change from my nominal. At 300 the MOA temp change was so minimal I didn't bother at this distance (think it said .35MOA at 600y, so half of that isn't even a click). Fired off the first round (aiming at center of a shoot and see) and it struck just right of the 9... thought that was weird because it was real high, and I thought it was me for a second. Emptied the mag and this is the end result (happy its a 1/2 MOA group at 3 bills and with pretty bad wind, etc) but the drop is WAY OFF! By my calculations it's almost 7 clicks/1.75 MOA off (5 inches to center from the 9 in the center of the group to the X). I thought that was weird. So then I went to 565 and put in the MOA change according to Sierra and I didn't even hit paper. In fact I shot almost 1/2 mil above the target. Adjusted again adjusted 7 clicks just to hit the top part of the paper, then had to adjust another 8 clicks to put it in the X, so that's 15 clicks off at that range. I loaded all my rounds at the 2572 (42.1) range and I didn't do anything out of the ordinary. So I have a few questions:
1) What does this mean? I'm something I did was off then I could see a few rounds going off, but all of them were pretty consistent and I shot 1/2 MOA pretty consistently that day. Every shot I dialed with the Sierra program past my zero range (100 yd) was substantially high.
2) Does this mean that I may reach longer ranges because there isn't as much drop as predicted?
3) Can Sierra be that far off?
4) Is there something I'm missing? I am not a master of felt recoil, but the shots did all feel pretty much the same and I didn't notice them anywhere near as hot as I was using during load development.
Below is my drop data. Just for shits and giggles I ran my data through my KAC iPhone program and it is nearly identical to the Sierra program.
Here are my nominal settings:
Rifle type and caliber? LR-308
Ammo? 168 SMK
Velocity? 2572
Altitude you shoot most at? 92
Nominal temperature (59F)? 85
Nominal barometric (29.53 in.Hg)? 30.01
Nominal Humidity (78%)? 75
Scope to bore height (in.)? 1.375
Your Zero distance (yds)? 100
Cross wind setting in ballistic program (10 mph?) 10 mph
Yards Inches MOA clicks
25 -0.51 1.95 8
50 0.02 -0.04 -0
75 0.19 -0.24 -1
100 0 0.00 0
125 -0.58 0.44 2
150 -1.55 0.99 4
175 -2.94 1.60 6
200 -4.76 2.27 9
225 -7.02 2.98 12
250 -9.76 3.73 15
275 -12.98 4.51 18
300 -16.7 5.32 21
325 -20.96 6.16 25
350 -25.77 7.03 28
375 -31.17 7.94 32
400 -37.16 8.87 35
425 -43.8 9.84 39
450 -51.09 10.84 43
475 -59.08 11.88 48
500 -67.8 12.95 52
525 -77.28 14.06 56
550 -87.56 15.20 61
575 -98.67 16.39 66
600 -110.67 17.61 70
625 -123.58 18.88 76
650 -137.46 20.19 81
675 -152.36 21.55 86
700 -168.32 22.96 92
725 -185.4 24.42 98
750 -203.65 25.93 104
775 -223.12 27.49 110
800 -243.88 29.11 116
825 -265.98 30.79 123
850 -289.48 32.52 130
875 -314.45 34.32 137
900 -340.93 36.17 145
925 -368.99 38.09 152
950 -398.69 40.08 160
975 -430.09 42.12 168
1000 -463.24 44.24 177
1025 -498.2 46.41 186
1050 -535.03 48.66 195
1075 -573.77 50.97 204
1100 -614.48 53.34 213
1125 -657.22 55.79 223
1150 -702.02 58.29 233
1175 -748.95 60.87 243
1200 -798.06 63.51 254
1225 -849.39 66.21 265
1250 -902.99 68.98 276
1275 -958.91 71.82 287
1300 -1017.2 74.72 299
1325 -1077.91 77.68 311
1350 -1141.09 80.72 323
1375 -1206.79 83.81 335
1400 -1275.05 86.97 348
1425 -1345.93 90.19 361
1450 -1419.46 93.48 374
1475 -1495.71 96.83 387
1500 -1574.72 100.25 401
1) All my loading procedure's are the same. The brass, powder, primers, seating depth, brass prep, etc are all the same. The only thing that changed was I opened a new box of 168 SMK's from a new lot, but can it really create that much of difference of impact at only 300 yards? The BC could be slightly different due to a new die, but can it create that much of difference in impact?
2) I weighed all my throws to make sure they come out to 42.1.
3) All COAL were the same at 2.775, in all IMI match brass, with FGMM primers, and IMR 4895 powder.
Firstly I confirmed my 100y zero with my CB shot (pulled it 1/4 inch left.. which by the way I'm seeing a pattern after logging my CB shots. All my CB shots are to the left anywhere from 1/4-1/2 inch). So after that I began confirming my real world drop data for Sierra's predicted drop. Sierra had a 5.3 MOA drop (16.5 inches), without adding in the temp change from my nominal. At 300 the MOA temp change was so minimal I didn't bother at this distance (think it said .35MOA at 600y, so half of that isn't even a click). Fired off the first round (aiming at center of a shoot and see) and it struck just right of the 9... thought that was weird because it was real high, and I thought it was me for a second. Emptied the mag and this is the end result (happy its a 1/2 MOA group at 3 bills and with pretty bad wind, etc) but the drop is WAY OFF! By my calculations it's almost 7 clicks/1.75 MOA off (5 inches to center from the 9 in the center of the group to the X). I thought that was weird. So then I went to 565 and put in the MOA change according to Sierra and I didn't even hit paper. In fact I shot almost 1/2 mil above the target. Adjusted again adjusted 7 clicks just to hit the top part of the paper, then had to adjust another 8 clicks to put it in the X, so that's 15 clicks off at that range. I loaded all my rounds at the 2572 (42.1) range and I didn't do anything out of the ordinary. So I have a few questions:
1) What does this mean? I'm something I did was off then I could see a few rounds going off, but all of them were pretty consistent and I shot 1/2 MOA pretty consistently that day. Every shot I dialed with the Sierra program past my zero range (100 yd) was substantially high.
2) Does this mean that I may reach longer ranges because there isn't as much drop as predicted?
3) Can Sierra be that far off?
4) Is there something I'm missing? I am not a master of felt recoil, but the shots did all feel pretty much the same and I didn't notice them anywhere near as hot as I was using during load development.
Below is my drop data. Just for shits and giggles I ran my data through my KAC iPhone program and it is nearly identical to the Sierra program.
Here are my nominal settings:
Rifle type and caliber? LR-308
Ammo? 168 SMK
Velocity? 2572
Altitude you shoot most at? 92
Nominal temperature (59F)? 85
Nominal barometric (29.53 in.Hg)? 30.01
Nominal Humidity (78%)? 75
Scope to bore height (in.)? 1.375
Your Zero distance (yds)? 100
Cross wind setting in ballistic program (10 mph?) 10 mph
Yards Inches MOA clicks
25 -0.51 1.95 8
50 0.02 -0.04 -0
75 0.19 -0.24 -1
100 0 0.00 0
125 -0.58 0.44 2
150 -1.55 0.99 4
175 -2.94 1.60 6
200 -4.76 2.27 9
225 -7.02 2.98 12
250 -9.76 3.73 15
275 -12.98 4.51 18
300 -16.7 5.32 21
325 -20.96 6.16 25
350 -25.77 7.03 28
375 -31.17 7.94 32
400 -37.16 8.87 35
425 -43.8 9.84 39
450 -51.09 10.84 43
475 -59.08 11.88 48
500 -67.8 12.95 52
525 -77.28 14.06 56
550 -87.56 15.20 61
575 -98.67 16.39 66
600 -110.67 17.61 70
625 -123.58 18.88 76
650 -137.46 20.19 81
675 -152.36 21.55 86
700 -168.32 22.96 92
725 -185.4 24.42 98
750 -203.65 25.93 104
775 -223.12 27.49 110
800 -243.88 29.11 116
825 -265.98 30.79 123
850 -289.48 32.52 130
875 -314.45 34.32 137
900 -340.93 36.17 145
925 -368.99 38.09 152
950 -398.69 40.08 160
975 -430.09 42.12 168
1000 -463.24 44.24 177
1025 -498.2 46.41 186
1050 -535.03 48.66 195
1075 -573.77 50.97 204
1100 -614.48 53.34 213
1125 -657.22 55.79 223
1150 -702.02 58.29 233
1175 -748.95 60.87 243
1200 -798.06 63.51 254
1225 -849.39 66.21 265
1250 -902.99 68.98 276
1275 -958.91 71.82 287
1300 -1017.2 74.72 299
1325 -1077.91 77.68 311
1350 -1141.09 80.72 323
1375 -1206.79 83.81 335
1400 -1275.05 86.97 348
1425 -1345.93 90.19 361
1450 -1419.46 93.48 374
1475 -1495.71 96.83 387
1500 -1574.72 100.25 401
