308 Brass Volumes

[waste_knot]

Just some data for the rest of you to comment on.
I measured the water volumes of 4 brands of 308 cases.
All weights are in grains All cases are new xcept resized LC. Primer pockets were plugged with putty.

1978 Win -- MT 154.7 WW 56.1
New Win -- MT 178.4 WW 53.2
LC 76 -- MT 176.8 WW 53.3
Lapua -- MT 173.1 WW 55.0
It will be interesting to see how the Lapua and the new Win brass compare through the crono with the same charge of IMR 4895

 

[RyeDaddy]

Re: 308 Brass Volumes

Measuring new brass straight from the package doesn't tell much.

My recent production Winchester brass holds 2.1 grains more water on average than my Lapua, and weighs 13 grains per case less than the Lapua. This is after being fireformed in my chamber and all trimmed to the same length.

 

[winxp_man]

Re: 308 Brass Volumes

I can add this info. This is from a post I posted on another forum.

Here are some Lapua .308 brass weights and how much they can hold. These are all at least once fired.

Brass GR Amount of H2O held by case in GR
177.2 held 56.3
176.3 held 56
176.5 held 55.8
176.6 held 56.1
177.2 held 55.1
177.2 held 55.6
176.4 held 55.9
177.1 held 55.8
177.9 held 55.9
177.5 held 56

So average is 55.84

Winchester Brass also at least once fired.

163.1 57.3
163.3 57.4
164.1 57.5
163.2 57.4
164.3 57.0
161.8 57.6
163.6 57.0
163.8 57.2
161.0 57.5
161.8 57.3

Average Grains held is 57.32

This is how it was with powder of various sorts. This brass was prep'd but the top was recently shot.

Winchester Brass Trim Length- 2.005 can hold 51.2 grains of IMR 4064

Winchester Brass Trim Length- 2.005 can hold 52.5 grains of Varget

Winchester Brass Trim Length- 2.005 can hold 53.3 grains of R-15

Lapua Brass Trim Length- 2.005 can hold 51.8 grains of R-15

Lapua Brass Trim Length- 2.005 can hold 51.2 grains of Varget

Lapua Brass Trim Length- 2.005 can hold 50.1 grains of IMR 4064


Here is the Federal Brass numbers:

These cases are once fired FGMM cases.
Case Weight: Case Capacity:
181.9 55.7
182.3 55.7
182.2 55.7
182.0 55.5
180.5 56.0
181.6 55.9
182.9 56.0
181.8 56.0
181.3 55.9
181.4 55.9

These cases are regular federal cases.

Case Weight: Case Capacity:
184.0 55.3
183.9 55.6
183.4 55.9
183.9 55.3
183.7 55.5
184.3 55.5
184.0 55.4
183.4 55.6
183.1 55.5
184.5 55.3




Aron-

 

[waste_knot]

Re: 308 Brass Volumes

Rye
Production chamber or match chamber. Bolt gun?

 

[winxp_man]

Re: 308 Brass Volumes

All mine are in a factory SPS Tac chamber.