Case capacity??

[surfclod]

I am just wondering if anyone knows the "official" case capacity for the .204 Ruger.

A guy who has the QuickLOAD software plugged my load info into the program to see how close it was to my results and while it was very close in performance (only a difference of 2.4% fps) the program said that this load exceeded the Maximum Average Pressure. However this load (26.6 grains of H322 for 32 grain V-Max) is about halfway between the recommended starting load and the maximum load from the Hodgen load chart.

The program is very detailed including such information as bullet seating depth, burning rate of powder, barrel length, and much, much more. Some of the info is user input while others is based on information that the program has in a database.

My first though was that the case capacity figure in the QuickLOAD software's database was off. I can't find it anywhere online so I filled 3 identical weighing cases with water. I found a case capacity of 33.2 grains of water for the .204 Ruger in my fired Hornady cases. The QuickLOAD uses a case capacity of 30.96 before bullet is seated, a usable case capacity of 29.124 grains H20 after the bullet is seated .222" deep.

Has anyone else checked case capacity or know what the case capacity is supposed to be for the .204????

[Hawkeye Joe]

Could the difference be that they used a full length sized case and you used a fireformed case. Your rifles chamber and how you size your cases(neck or full) will dictate your rifles case capacity. Hope this helps.

[surfclod]

I just found a list of case capacities!!
http://kwk.us/cases.html

Its funny cause I was trying to find a partial list that I had found earlier so I put in the same Google info and the list I wanted didn't come up (even with exact inputs) so I just check out some of the new results and I found above linked list. That list is based on a program that calculated case capacity based on the dimensions of the case so, just like anything in this game, real world results will vary.

Anyways the program results list the 204 as having 33 grains of H2O capacity so I think I am pretty close with my fireformed cases giving 33.2gr. The QuickLOAD program recommends using fireformed cases to get the case capacity data for higher pressure rounds. Those below 30,000 psi peak pressure they recommend resized cases. If I had $150 kicking around I might buy the program just to play with different load ideas and crazy wildcats.


I also got an email from the fella with the QuickLOAD program and when he input the new case capacity his results were within 30 fps of my chronographed results. I find that to be very impressive considering the Chrony is supposed to be 99.5% accurate. The 30 fps difference is only 0.75% so we are really splitting hairs here when comparing real world results with what the software gives.