AB Link -Temp/MV input

[BattleAxe]

Quick question on this feature in AB link...in this window at the bottom of the screen do you insert the full MV number w/current OAT or just the FPS per degree of temp change like you do in shooter?

 

[jbailey]

think you have it right. Although I would stack the temps in order of lowest to greatest. Also, there might be a bug on the Kestrel. If you select another gun, and then return to this gun, the Kestrel turns OFF the MV-temp feature - at least it does in mine.

Also, I would grab a wilder range of MVs and temps. 72 to 77 isn't much of a range. I have data from 20* to 85*, for example.

 

[BattleAxe]

Thanks. Haven't noticed if mine is turning off yet. Just upgraded to this kestrel from a non-AB version so I haven't been switching platforms yet. As for the temps...yes...I need to do that but this is Florida so getting numbers on a cold day can be difficult sometimes. I may not have many more chances this year.

 

[Holliday]

Quick question on this feature in AB link...in this window at the bottom of the screen do you insert the full MV number w/current OAT or just the FPS per degree of temp change like you do in shooter?

The way you have it is correct.

 

[DocUSMCRetired]

The way you have entered it is correct, however you need a minimum of 20 degrees Fahrenheit and preferred more between inputs.

 

[Timo Turl]

I would love AB to measure / calculate temp sensitivity with the most popular powders and match ammunition and to have that populated by ABM in the Kestrel just like they do with drag curves & with a toggle on/off feature.

 

[DocUSMCRetired]

I would love AB to measure / calculate temp sensitivity with the most popular powders and match ammunition and to have that populated by ABM in the Kestrel just like they do with drag curves & with a toggle on/off feature.

We are talking about this internally. The issue is lot to lot variation. I have personally seen the same powder, across two different lots give different results. But we are talking about it.

 

[Timo Turl]

We are talking about this internally. The issue is lot to lot variation. I have personally seen the same powder, across two different lots give different results. But we are talking about it.

I can understand that but the same is true for bullets to some extent with lot to lot variation and you managed to create the G7 so in theory you could do the same for powder temp sensitivity. It might need tweaking at the shooter level like the DSF or muzzle calibration but it would be a big jump forward for the industry and again AB could be at front of the debate and it could work for both powders and purchased ammunition or even ammunition supplied to the military. If you don't have the time or inclination to come up with your own temp sensitivity table then having the option to use yours would be huge. Just another advancement in long range shooting

 

[Holliday]

We are talking about this internally. The issue is lot to lot variation. I have personally seen the same powder, across two different lots give different results. But we are talking about it.

I recently saw a 30 fps change with Varget from 70 degs F to 40 degs (same can). 1 fps per degree. Does this seem consistent with ABs findings?

 

[DocUSMCRetired]

I recently saw a 30 fps change with Varget from 70 degs F to 40 degs (same can). 1 fps per degree. Does this seem consistent with ABs findings?

This is not consistent with my current lot of Varget which sits at about a 0.4.

 

[DocUSMCRetired]

I can understand that but the same is true for bullets to some extent with lot to lot variation and you managed to create the G7 so in theory you could do the same for powder temp sensitivity. It might need tweaking at the shooter level like the DSF or muzzle calibration but it would be a big jump forward for the industry and again AB could be at front of the debate and it could work for both powders and purchased ammunition or even ammunition supplied to the military. If you don't have the time or inclination to come up with your own temp sensitivity table then having the option to use yours would be huge. Just another advancement in long range shooting

We are looking in to it, and a couple other things as well. You tend to have more powder lots, than you do bullet lots on the market. So it is something that needs to be handled with care.

 

[Holliday]

This is not consistent with my current lot of Varget which sits at about a 0.4.

Here is my data from today from a new "lot" . Actually it's two cans of different lots mixed to create a 2lb lot. These are the lowest numbers I have seen from this load.....really low.

MagnetoSpeed XFR Results:

.308 new powder lot
7260 DA 36.4 deg F
46.5 grains Varget
155 Lapua Scenars
Lapua brass
Federal 210 match primers

Device: V3
Sensitivity: 3
Units: ft/s


Shots: 10
Max : 2915
Min : 2894
ES : 21
Avg : 2901
SD : 6
1: 2902
2: 2899
3: 2895
4: 2902
5: 2915
6: 2906
7: 2904
8: 2900
9: 2894
10: 2899

 

[BattleAxe]

While we're on this topic...once a solution is reached, is the spin drift value already added to the WS1/WS2 values, or is this a separate value to be accounted for by the user?

 

[jbailey]

While we're on this topic...once a solution is reached, is the spin drift value already added to the WS1/WS2 values, or is this a separate value to be accounted for by the user?

Yes, it is added into the WS1 and 2 values -- UNLESS you turn it OFF. To turn it off and on, go to ENVIRONMENT and scroll down list a ways until you see SpnDft Yes/No. Toggle left and right arrows to turn on and off.

Note: to get accurate spin drift, make sure your bullet length and barrel twist (rate and direction) are accurate. It doesn't start to matter until your about 1000 yards out...