A&D 120 scale

[Jimbo42]

Couple questions with the FX 120 scale and humidity.
Does the scale compensate for high humidity days? Loading 30.2 grains of Varget on a day that’s 53% humidity compared to a day that’s 73% humidity, how is my load affected, or at all?
I weighed the cup on the scale on a low humidity day and wrote down the weight. You can see the fluctuation in weight “higher” on more humid days.
If I load on a humid day and shoot a couple days later on a low humidity day will I see problems?
I not able to wrap my head around this issue.
Thanks
Jim

 

[BKA]

I have this scale but only use it in a controlled environment. I imagine on high humidity days that your powder will absorb some moisture allowing each kernel to gain weight. The added moisture also has the potential to change the burn rate if sealed tightly in the cartridge. I'd expect things to be sightly different between high humidity days and low humidity days. Does it really matter for your discipline? Does it show up on the chrony or on the target?

 

[Jimbo42]

I have this scale but only use it in a controlled environment. I imagine on high humidity days that your powder will absorb some moisture allowing each kernel to gain weight. The added moisture also has the potential to change the burn rate if sealed tightly in the cartridge. I'd expect things to be sightly different between high humidity days and low humidity days. Does it really matter for your discipline? Does it show up on the chrony or on the target?

Just haven’t had the time to test it. We shoot
2-400 yard varmint targets. Most of these guys have guns that’ll shoot in the low 2’s or better. It’s pretty darn tough competition.

 

[R.Morehouse]

I load in my house and put the charges in 1 dram vials. If I have to load at the range, it happens much faster for me ( I use a beam scale ) than weighing them and the atmosphere of the powder is what it was in my reloading room............Just some food for thought.

Regards
Rick

 

[nmkid]

Never experienced any "humidity" problems when I lived in Virginia for 10 years.

 

[JFrank]

Couple questions with the FX 120 scale and humidity.
Does the scale compensate for high humidity days? Loading 30.2 grains of Varget on a day that’s 53% humidity compared to a day that’s 73% humidity, how is my load affected, or at all?
I weighed the cup on the scale on a low humidity day and wrote down the weight. You can see the fluctuation in weight “higher” on more humid days.
If I load on a humid day and shoot a couple days later on a low humidity day will I see problems?
I not able to wrap my head around this issue.
Thanks
Jim

My A&D glass cup weighs 869.82 gr during the winter or summer, yes it can vary a few 1/100 but my check weights are always the same 40.0 grain, hot dry air will effect the speed of the load as much as 30 fps compared to colder months.

 

[Straightshooter1]

Couple questions with the FX 120 scale and humidity.
Does the scale compensate for high humidity days? Loading 30.2 grains of Varget on a day that’s 53% humidity compared to a day that’s 73% humidity, how is my load affected, or at all?
I weighed the cup on the scale on a low humidity day and wrote down the weight. You can see the fluctuation in weight “higher” on more humid days.
If I load on a humid day and shoot a couple days later on a low humidity day will I see problems?
I not able to wrap my head around this issue.
Thanks
Jim

To answer your question . . . no, the FX-120i will not compensate for variations in humidity.

Powder in higher humidity will gain moisture, which will make it will burn slower and weigh more (weighing more means less powder for your target weight). However, it takes quite a bit of time for the powder's moisture to equalize. The time it takes to load cartridges isn't going to change it's moisture much even with a high difference in humidity and the powder's moisture content.

Loaded cartridges can leak at different rates, mostly depending on the difference is air pressure within the cartridge and the atmospheric pressure. When the bullet is seated, the cartridge is temporarily pressurized and some air within slowly leaks out to equalize with the outsize air pressure. That leaking can still continue when outside air pressure changes causing air to either move into or out of the cartridge. When outside air leaks into the cartridge, then it's humidity can effect the powder's moisture content, but again, it's a slow process that takes many days. This could be an issue like when shipping your loaded cartridges on a plane (planes tend to have very low pressure in their cargo holds and passenger cabins) for an overseas competition. This is where I'd probably want my primer pockets sealed as well at the necks. Loading and shooting just a couple day later where you live with different atmospherics isn't going to allow enough, if any, leaking to effect the powder inside your cases.

 

[Jimbo42]

To answer your question . . . no, the FX-120i will not compensate for variations in humidity.

Powder in higher humidity will gain moisture, which will make it will burn slower and weigh more (weighing more means less powder for your target weight). However, it takes quite a bit of time for the powder's moisture to equalize. The time it takes to load cartridges isn't going to change it's moisture much even with a high difference in humidity and the powder's moisture content.

Loaded cartridges can leak at different rates, mostly depending on the difference is air pressure within the cartridge and the atmospheric pressure. When the bullet is seated, the cartridge is temporarily pressurized and some air within slowly leaks out to equalize with the outsize air pressure. That leaking can still continue when outside air pressure changes causing air to either move into or out of the cartridge. When outside air leaks into the cartridge, then it's humidity can effect the powder's moisture content, but again, it's a slow process that takes many days. This could be an issue like when shipping your loaded cartridges on a plane (planes tend to have very low pressure in their cargo holds and passenger cabins) for an overseas competition. This is where I'd probably want my primer pockets sealed as well at the necks. Loading and shooting just a couple day later where you live with different atmospherics isn't going to allow enough, if any, leaking to effect the powder inside your cases.

Thank you for that response. Helps me understand what’s going on !

 

[ShtrRdy]

I've been using these humidity control packs to manage the humidity of my powder. Put a pack in the jar of powder and in a zip-loc bag which holds the loaded cartridges. I use the 49 % ones.

Two Way Humidity Control Packs - Boveda® Official Site

Boveda is the global leader in two way humidity control packs for preserving humidity sensitive products like cigars, cannabis and guitars.

bovedainc.com