LC, RP, FC Case Comparision (223)

[Will Lee]

I have read on my 4 favorite Forum (many times) that Lake City cases are thicker therefore have less volume so charges need to be reduced slightly to avoid excessive pressure.

Being retired and with tons of free time on my hands I did a little test today to satisfy my own curiosity.

Here is the data (all cases were SS Media tumbled and Ultrasonic cleaned with new CCI 450 primers). All cases were randomly selected. All cases weight on RCBS digital scales. Also all of these cases have been cycled several times. All cases trimmed to 1.750.

RP
96.0
95.5
94.9
94.1
96.6
AVG=95.48 ES=2.5

FC
96.0
96.4
96.2
96.5
95.9
AVG=96.2 ES=.5

LC-08
95.2
95.3
95.3
95.9
96.1
AVG=95.56 ES=.9

Selected 1 case from each group of the same dry weight (almost) and filled them with water.

LC = 96.1 = 126.4
FC = 96.0 = 126.5
RP = 96.0 = 126.3

Needless to say there is some contradiction in what I've read and what this data shows.

 

[jet_lagged]

Re: LC, RP, FC Case Comparision (223)

Good info.

Accurate Shooter did something similar a awhile back. They do show some of the foreign military (RG, PMP, IMG) being heavier.

http://www.accurateshooter.com/cartridge-guides/223rem/

LC for 7.62/.308 and .30-06 still seem to be heavier than most commercial brass, but I guess for the 5.56 they really needed the case capacity to get the powder charge up to where it needs to be.