Looking for advice on charge weight

[Gil P.]

I've worked up load with my 6.5x47 Lapua using 140 Bergers, and RL 16.

Theres a node from 39.8-40.1gr. 40.1 gr produced velocities just above 2800 fps. I tested this load in the shade at 99 deg. I settled on 40.0gr

When I went to shoot this load I shot it in the sunlight and the high velocities where around 2835 fps,SD 10 with 40.0gr. I don't have my data with me but I think the lows were in the 2980`s.

I thought the sun was heating the rounds unevenly in the metal magazine and shot some more rounds from the shade. This time my velocities were in the high 2990's and I got an SD of 5.

What would you do? Reduce the charge weight closer to the bottom of the node, or start over and purposefully let the rounds heat up in the sunlight before finding a new node?

 

[manitou210]

Quit using reloader powders the are double base and go crazy on hot days at range go to H 4350

 

[HillBillyPirate]

New to the 6.X47 Lapua but not reloading. From research a lot of PRS shooters are running Varget with this round. Varget is a great powder with slight changes due to temperature variances. Give it a shot.

 

[Gil P.]

The thing is, Varget and H4350 are in short supply right now. I ran out of Varget and only have about 5 pounds of H4350 left.

From what I read about RL16, it's supposed to me temp stable. I was wondering if this powder gets more sensitive if it's compressed. I'm using 40 gr and I can just hear powder rattle around. I'm going to keep experimenting with it and see how it reacts of I try to keep it in a pack put of the sun.

 

[Falfan2017]

Quit using reloader powders the are double base and go crazy on hot days at range go to H 4350

This is not exactly accurate. Reloader 15 and 17 can be very temp unstable. Rl 16 is their treated formula that is one of the more stable powders out there

 

[Falfan2017]

What kind of crono are you using? This could be a crono issue if you’re moving in and out of the shade.

 

[Rsadams]

If it's all you can get , then it's all you can get.. If you're just shooting at the range for fun I would be safe for sure...

 

[Gil P.]

What kind of crono are you using? This could be a crono issue if you’re moving in and out of the shade.

Magnetospeed, it shouldn't affect the velocity.

 

[Gil P.]

If it's all you can get , then it's all you can get.. If you're just shooting at the range for fun I would be safe for sure...

I like to shoot in club matches, but I've got about a month before the next one. It gives me time to test the sensitivity of this powder a little more.

 

[David Christian]

I've worked up load with my 6.5x47 Lapua using 140 Bergers, and RL 16.

Theres a node from 39.8-40.1gr. 40.1 gr produced velocities just above 2800 fps. I tested this load in the shade at 99 deg. I settled on 40.0gr

When I went to shoot this load I shot it in the sunlight and the high velocities where around 2835 fps,SD 10 with 40.0gr. I don't have my data with me but I think the lows were in the 2980`s.

I thought the sun was heating the rounds unevenly in the metal magazine and shot some more rounds from the shade. This time my velocities were in the high 2990's and I got an SD of 5.

What would you do? Reduce the charge weight closer to the bottom of the node, or start over and purposefully let the rounds heat up in the sunlight before finding a new node?

@Gil P. I don't think you have a problem with the powder. R16 has not been an issue for me regardless of weather.

How many rounds did you have on that barrel before you did the first work up? How many are on it now? Do you think you have a consistent barrel cleaning technique? What is your process for load work up that targeted 40.0 grains? Can you share your data for the load work up--FPS for each shot along with average and ES for each charge weight?

 

[Gil P.]

Ignore row A. That one wasnt loaded in the same way B and C where. I may re do this test because my bullets where just touching the lands, whereas they are now seated 20 thou off.

Barrel had about 20 rounds on it before this test that I used to do a break in procedure and pressure test. Since this velocity test the barrel has 110 rounds on it.

My method of cleaning is good. I use bore tech rods with a Lucas bore guide. Bore tech powder solvent and Sweets 7.62. I wet the barrel with a couple patches, let it sit, scrub with a nylon or bronze brush saturated with solvent, clean l, repeat with Sweets. Though I stopped using Sweets since this powder doesn't produce hardly any copper fouling.

My method for finding this load was loading cases in increasing charge weights and shooting them. I'm looking for a node where there is little increase in velocity between charge weights. In the past I've done ladder tests at 400-600 yards. I was trying something new with this velocity test.

The increase in velocity due to shooting in direct sunlight and then the velocity dropping back down when shooting in the shade happened during the same shooting session less than 20 minutes apart. I don't think that had anything to do with the barrel needing to be broken in.

 

[David Christian]

Ignore row A. That one wasnt loaded in the same way B and C where. I may re do this test because my bullets where just touching the lands, whereas they are now seated 20 thou off.

Barrel had about 20 rounds on it before this test that I used to do a break in procedure and pressure test. Since this velocity test the barrel has 110 rounds on it.

My method of cleaning is good. I use bore tech rods with a Lucas bore guide. Bore tech powder solvent and Sweets 7.62. I wet the barrel with a couple patches, let it sit, scrub with a nylon or bronze brush saturated with solvent, clean l, repeat with Sweets. Though I stopped using Sweets since this powder doesn't produce hardly any copper fouling.

My method for finding this load was loading cases in increasing charge weights and shooting them. I'm looking for a node where there is little increase in velocity between charge weights. In the past I've done ladder tests at 400-600 yards. I was trying something new with this velocity test.

The increase in velocity due to shooting in direct sunlight and then the velocity dropping back down when shooting in the shade happened during the same shooting session less than 20 minutes apart. I don't think that had anything to do with the barrel needing to be broken in.
View attachment 1202655

I normally don't do real testing until I see the barrel speed stabilize, which for me happens after 200 rounds on it. Yes, I anecdotally pay attention to the numbers as the barrel is breaking in, but don't find my true node until post 200 rounds. For example, I was in a rush to break in a new barrel on a rifle last month and found my initial testing done at the 150 round mark to be .5 grains higher than what I just saw while retesting this week at the 300 round mark.

 

[Willie]

New brass and new barrel = frustration.

 

[Rsadams]

I like to shoot in club matches, but I've got about a month before the next one. It gives me time to test the sensitivity of this powder a little more.

That's good it should only be getting cooler...

 

[Gil P.]

I normally don't do real testing until I see the barrel speed stabilize, which for me happens after 200 rounds on it. Yes, I anecdotally pay attention to the numbers as the barrel is breaking in, but don't find my true node until post 200 rounds. For example, I was in a rush to break in a new barrel on a rifle last month and found my initial testing done at the 150 round mark to be .5 grains higher than what I just saw while retesting this week at the 300 round mark.

I'll take your advice and shoot 100 more before doing another charge weight test.