just some reference points on mil 5.56 case volume

[ar10ar15man]

i am in the brass business. i have a couple of lots of brass that came in recently. i took the time to sample the brass for weight and volume

wwc11 94.7+.8/-1.3 vol 30.2
lc08 92.3+1/-.9 vol 30.4
lc09 92.3+.2/-.2 vol 30.8
lc10 92.0 +1/-1 vol 30.8
lc11 92.2 +.5/-1 vol 30.5

fed crimped 91.6 +2.5/-1.5 vol 30.3 (commercial 223 rem not mil)

never use someone else's data for target loads..sample you own brass and go from there

 

[LCazador]

My Lake City virgin brass is 92.4 and 92.3g. , O9 and 08 respectively . So you're right on . BTW I'll second that excellent advice on your statement " sample your own brass " ! , check and weigh before you start loading !

 

[gilream]

I understand that the 1st number listed is the average case weight.

I'm guessing the +../-.. is the variance from the average

And the vol number is grains of water? or would that be grains of powder?

Do these numbers tell you anything pertaining to hand loading or do they simply reflect the quality/consistency of the lot of brass that you are dealing with?

What percentage of cases did you test from each lot?

 

[ar10ar15man]

I understand that the 1st number listed is the average case weight.yes

I'm guessing the +../-.. is the variance from the averageyes

And the vol number is grains of water? or would that be grains of powder?water at 77degrees

Do these numbers tell you anything pertaining to hand loading or do they simply reflect the quality/consistency of the lot of brass that you are dealing with?hmmmm how to adjust your load for a lot, what to expect in variation so you do not over charge...to check your own

What percentage of cases did you test from each lot?.....that is almost funny...i weighed a handful, devided by actual count, did diviation on 10..pure random

 

[amlevin]

Just curious but were these case all sized equally before measuring volume? Trimmed to equal length?

 

[ar10ar15man]

yes

Just curious but were these case all sized equally before measuring volume? Trimmed to equal length?

 

[Ackman]

Did you fire them all in the same chamber before trimming?

 

[ar10ar15man]

no and it does not matter...
the brass is deprimed, small based sized, then full lenght sized......trimed to lgth and a spent primer is intalled upside down.

Did you fire them all in the same chamber before trimming?

 

[Ackman]

no and it does not matter...
the brass is deprimed, small based sized, then full lenght sized......trimed to lgth and a spent primer is intalled upside down.

Did you fire them all in the same chamber before trimming?

I've been throught this case weighing/volume measuring stuff. You're talking about comparing internal volume along with weight. Fireform them in the same chamber and leave 'em that way.

 

[bigedp51]

Cartridge Case Capacities

http://kwk.us/cases.html

"When measuring the water capacity (volume) of a case, it's better to use a fired case before it is resized, since this is closer to the size of the case expanded at firing"

From Quickload

"Besides the standard entered information the actual internal volume or cartridge case capacity of the used cases is an important parameter for QuickLOAD to obtain usable predictions. The internal case volume has to be established by weighing empty once fired cartridge cases from a production lot and filling the cases with fresh or distilled water (H2O) up to the point of overflowing and weighing the water filled cases."


Quickload Instructions: