Touch a tissue corner to flatten
Are you loading for hunting or for competitions? Think the method involves using a fired, unsized case, using the spent primer as a plug. I'd be interested to see your results with the 21st century plug.
If its for hunting, grab 10-15, get the water weight of each and average them. You will find that most are within a few tenths- which wont be enough to really throw off the grouping if you are on an OBT node. Here is an example of my 22-250 cases, that vary +/- .4 in only a few cases. I can expect a range of +/- 20 fps velocity difference from the average, if my math is right.
Lapua
avg: 45.072
Dry Wet
167.9 | 212.6
167.5 | 212.8
167.7 | 212.5
167.7 | 213
168 | 212.8
167.4 | 212.7
167.9 | 212.5
167.5 | 212.7
168.1 | 212.4
167.4 | 212.8
167.7 | 212.7
167.8 | 212.8
167.8 | 213
167.2 | 212.3
167.9 | 212.9
167.7 | 212.8
167.7 | 212.8
167.4 | 212.7
167.9 | 213
167.9 | 213
166.4 | 212.7
167.7 | 212.3
167.4 | 212.6
167 | 212.9
167.4 | 212.5
AVG: 167.6 | 212.712
Are you loading for hunting or for competitions? Think the method involves using a fired, unsized case, using the spent primer as a plug. I'd be interested to see your results with the 21st century plug.
If its for hunting, grab 10-15, get the water weight of each and average them. You will find that most are within a few tenths- which wont be enough to really throw off the grouping if you are on an OBT node. Here is an example of my 22-250 cases, that vary +/- .4 in only a few cases. I can expect a range of +/- 20 fps velocity difference from the average, if my math is right.
Lapua
avg: 45.072
Dry Wet
167.9 | 212.6
167.5 | 212.8
167.7 | 212.5
167.7 | 213
168 | 212.8
167.4 | 212.7
167.9 | 212.5
167.5 | 212.7
168.1 | 212.4
167.4 | 212.8
167.7 | 212.7
167.8 | 212.8
167.8 | 213
167.2 | 212.3
167.9 | 212.9
167.7 | 212.8
167.7 | 212.8
167.4 | 212.7
167.9 | 213
167.9 | 213
166.4 | 212.7
167.7 | 212.3
167.4 | 212.6
167 | 212.9
167.4 | 212.5
AVG: 167.6 | 212.712
I guess I have a different outlook than Mike. QL lists an estimate of how the charge will perform, and lists the time it takes for the bullet to leave the muzzle- (barrel time) for the range of charges.
If you take the time to enter your guns profile, measure your components (bullets weight, length, diameter, case length and H2o capacity) and enter them into QL, adjust the weighting factor correctly for the cartridge, adjust the burn rate to match chronographed velocities, it can estimate what will be a performing charge and what would be a waste when coupled with Chris longs node tables. The more precise the input is, the more accurate the estimates are. Should it be your only source for load data? Absolutely not. QL is a great supplement to show you what you can expect with YOUR components. it can give an understandable explaination why your seeing pressure signs when your at the min load of published data and why you are not seeing pressure signs when you are 3 grains over published max. If it can be used to validate performing loads, show why a component combination produces horrible results in one rifle but the same load is a performer in another, why can't it predict (I think estimate is a better word) a good load? In all honesty, it's made me a safer reloader because I can see where I will be pushing the line of saami pressure and I can see which range of charges I can focus on that give me the fastest velocity at the safer pressure levels and greatest accuracy.
I'll say again though, it shouldn't be the only source used when developing a load. Stay safe, caution first, start low, work up, watch for the telling signs of approaching danger.
Without knowing your capacity or velocity, and going by the supplied info, I get
at 2.800 ( .294 seating depth in QL):
+00.0 108 46.20 2616 2362 61771 11946 95.8 0.844 !DANGEROUS LOAD-DO NOT USE!
at 3.079 (.015 seating depth in QL):
+00.0 97 46.20 2468 2103 49558 12178 93.7 0.931
What is your case capacity, velocity and cartridge OAL?
Do you happen to have 8" of barrel that you're not telling us about?