Powder sweet spot..... A discussion

[Mulligan]

The data below is of a new-to-me powder being used in my dasher. For the sake of this discussion, the powder maker and type is irrelevant.
I rarely use my labradar when tuning, so I do not have a robust velocity data set. For me, the chronograph is distracting and has been misleading at times. I have found I shoot smaller if I just tune with the target data. But, maybe, that's just one of my many quirks?

What I am seeing is the tune or node is much flatter than the velocity data would suggest. In other words, adjusting powder charge to maintain a previously selected velocity would in this case not have resulted in the best tune.
I have also noticed this with other powders including Hodgdon's "Extreme" powders.


In the data above there are green boxes that have {no vel data} printed in them. This is where I shot a small three shot ladder to find the tune before a match. In this case it is with my HG shooting 600 yard BR.

For you folks that tune for each match, and or tune/load at the range, do you see the same thing?

Thanks
CW

 

[Dave M.]

I assume you are shooting your 6 Dasher for mostly 600 yard comps, like you stated this is for your 600 yard BR HV gun.
I would suggest that you don’t tune your rifle for each match unless you have endless components and really want to burn barrels out quickly. Finding a really good 600 yard load isn’t terribly hard if you follow a set process. I suggest you select a bullet that is a good fit for your FB and tune a quality load with it. You can continue to refine your load as needed but it should be robust enough to shoot the same load for 200-400 shots.
dave
dave

 

[Dave M.]

Mulligan,
As an example, I have been shooting the exact same load in my dasher for the last 1075 rounds
Berger 105g VLD
33.1g of RL-15
.009” in to the lands
.003-.004” neck tension
Anneal after each fire

 

[Mulligan]

Mulligan,
As an example, I have been shooting the exact same load in my dasher for the last 1075 rounds
Berger 105g VLD
33.1g of RL-15
.009” in to the lands
.003-.004” neck tension
Anneal after each fire

I have tried that and it worked well with RL-16 when I was shooting F-Class.
For BR, I do not want to leave anything on the table. I test before each match, and adjust as needed because the competition can be fierce.
CW

 

[JFrank]

@Mulligan
Assuming these are all at the same elevation/location I see a .04gr movement of your node throughout a 40 degree temperature swing, maybe the air in Colorado has something to do with it. My tuner range is 2000 ft while DC is 3400 ish ‘ and from 20 degrees to over 100 and still the node only moves a couple tenths on paper.

 

[Dave M.]

I have tried that and it worked well with RL-16 when I was shooting F-Class.
For BR, I do not want to leave anything on the table. I test before each match, and adjust as needed because the competition can be fierce.
CW

Please explain how you test before each match without wasting components and putting unnecessary rounds through your barrel. I’m very anxious to hear your response.

 

[Mulligan]

Please explain how you test before each match without wasting components and putting unnecessary rounds through your barrel. I’m very anxious to hear your response.

I don’t consider testing a waste of components. Barrels are consumables. I actually get as much enjoyment from loading and testing as I do attending matches. It is not a waste, it’s fun.
CW

 

[Mulligan]

@Mulligan
Assuming these are all at the same elevation/location I see a .04gr movement of your node throughout a 40 degree temperature swing, maybe the air in Colorado has something to do with it. My tuner range is 2000 ft while DC is 3400 ish ‘ and from 20 degrees to over 100 and still the node only moves a couple tenths on paper.

Jim,
I am shooting in very dry, fairly thin air. The range I shoot at the most is around 4800’ and 8-12% relitive humidity is common. If the RH gets above 50% it’s an anomaly, except during the Southwest Monsoon.
I have to move H4895 .4gr in the same temperature range as the above info.
CW

 

[JFrank]

Crap’ I see my typo of .04 rather than .4 gr

I’m loosing it man’

 

[Mulligan]

Crap’ I see my typo of .04 rather than .4 gr

I’m loosing it man’

The winters are long in the frozen north. It’s nothing some sunshine and laughter wont fix. Besides, I knew what you meant.
It’s all good brother.
CW

 

[Northridge]

The data below is of a new-to-me powder being used in my dasher. For the sake of this discussion, the powder maker and type is irrelevant.
I rarely use my labradar when tuning, so I do not have a robust velocity data set. For me, the chronograph is distracting and has been misleading at times. I have found I shoot smaller if I just tune with the target data. But, maybe, that's just one of my many quirks?

What I am seeing is the tune or node is much flatter than the velocity data would suggest. In other words, adjusting powder charge to maintain a previously selected velocity would in this case not have resulted in the best tune.
I have also noticed this with other powders including Hodgdon's "Extreme" powders.

View attachment 1325713
In the data above there are green boxes that have {no vel data} printed in them. This is where I shot a small three shot ladder to find the tune before a match. In this case it is with my HG shooting 600 yard BR.

For you folks that tune for each match, and or tune/load at the range, do you see the same thing?

Thanks
CW

Agreed clay and I am the same, chrono not typically used and for the same reasons, if I have chroni out it’s used as reference vs a location…

Shawn Williams

 

[Brians356]

Barrels are consumables. I actually get as much enjoyment from loading and testing as I do attending matches. It is not a waste, it’s fun.

Re-barreling is fun as well?
-

 

[Evan]

I don’t consider testing a waste of components. Barrels are consumables. I actually get as much enjoyment from loading and testing as I do attending matches. It is not a waste, it’s fun.
CW

I’m with you on that. I enjoy testing and tuning more than competing and I do it pretty much every week while the weather is suitable. “Saving a barrel and components” reminds me of guys who buy a new car and then limit how much they drive it cause they don’t want to “put the miles on it.”

To your question: I don't use a chrono, so I can’t say what the velocity does, but my powder nodes stay parked for a given condition and the same lot of powder across the life of the barrel. Crossing 40 or more degrees means I load at the bottom of my node for the morning so I don’t climb out of it by the end of the match when temps are peaking. Most of the nodes I find are 0.3gns wide or less in BR and x47 sized cases. Frequently less. I haven’t found any “temperature insensitive” powders yet despite what the advertising implies.

Fun sidenote: I was shooting a lot of varget from 2007 and finished it off a couple weeks ago. Across Jerry’s labradar, it clocked 2930fps. Opened my new lot from 2022. Same charge only clocked 2820fps. Still shot really nice and the ladder showed there was still a node there despite the >100fps change but wow! Thats almost like a different class of powder it was so much slower.

 

[Mulligan]

I haven’t found any “temperature insensitive” powders yet despite what the advertising implies.

Marketing .............

CW