Case capacity ?

[wisconsinteacher]

Nosler #7 says 6.5 Grendel brass can hold 33 grains of water. I just measure a few of mine and average 32.6 grains. So can I load my test ammo .3 lower than max and be okay. I would check for pressure signs but I want to know if my brass is close enough to Noslers specs.

 

[DrMike]

Are you measuring once-fired cases? Or are they virgin? Nosler is reporting case capacity to represent their chamber. Fascinatingly enough, QL lists 35 grains of water as case capacity for the 6.5 Grendel. I'd recommend working up your load to find your maximum. However, loading below maximum listed charge is likely safe. It is still a good idea to work up to ensure safety.

 

[wisconsinteacher]

The brass has been fire formed in my rifle from 7.62 brass.

 

[FOTIS]

Start low work up slow.

 

[JD338]

Keep in mind that ANY published load date is a reference and every rifle has its own max.
This is why you should always start low and work up to your MAX.

JD338

 

[RiverRider]

Yup. There are too many variables to focus so hard on just one of them. As a handloader you just have to always be on your toes! It can be a little nerve-wracking at times when you're new at it. Just do the steps: work up a little at a time and watch for pressure signs. A time or two you will likely see that you've gone to far. Some say the rifle will talk to you. It's true, it will, but it's much better to learn to hear it whispering. If you do that, you'll likely never have a rifle YELL at you, which is definitely undesirable!

 

[DrMike]

Some say the rifle will talk to you. It's true, it will, but it's much better to learn to hear it whispering. If you do that, you'll likely never have a rifle YELL at you, which is definitely undesirable!

Well said, RR. Well said, indeed.

 

[onesonek]

I just measure a few of mine and average 32.6 grains. So can I load my test ammo .3 lower than max and be okay.

Like all those said start low and work up, so do I.
Also, you can not correlate the load difference as you proposed here. It just don't work that way. As mentioned also, too many factors involved.

 

[onesonek]

Some say the rifle will talk to you. It's true, it will, but it's much better to learn to hear it whispering. If you do that, you'll likely never have a rifle YELL at you, which is definitely undesirable!

Well said, RR. Well said, indeed.

Indeed, very much so!

 

[Silent Sam]

That would work if you were using water as a propellant. Water does not equal powder.

 

[DrMike]

That would work if you were using water as a propellant. Water does not equal powder.

True, few of us load with water. However, it does permit measuring case capacity (volume), which permits an estimate of the amount of powder that can be loaded. If a person wished to be precise, they could determine the density of powder chosen and perform appropriate calculations and get a slightly different estimate. However, they could be speaking of volumes that are insignificant.

 

[nvbroncrider]

Good point Sam, its just a reference. Just like 223 vs 5.56 it is slight and generally not an issue. But once you get them good and hot that little bit of difference can be the difference from hot but safe to hot and dangerous. Always best to give yourself a little cushion rather than jump too far and find out the hard way.

 

[Silent Sam]

I understand the uses of determining case capacity. Using water is easy and has a constant density. Grains of water equal a specific volume. Directly basing changes in powder weight based on a given volume of water expressed in grains (weight) is pure folly. There is no correlation and is no way to approach handloading safely.