I was wondering if there is any case volume differences between factory new (winchester) 308 and FL sized once fired cases. I am hoping to develop a load and have some that I have fired and some that are still factory fresh. Thanks.
Case volume difference: new vs FL sized
- Thread starter turbohardtop
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Re: Case volume difference: new vs FL sized
I think you won't see hardly any difference, especially if they are all from the same lot of brass. If they are different brands then all bets are off.
Fill a couple up with water and weigh them to see how much variation you have.
I think you won't see hardly any difference, especially if they are all from the same lot of brass. If they are different brands then all bets are off.
Fill a couple up with water and weigh them to see how much variation you have.
Re: Case volume difference: new vs FL sized
Same batch/lot of brass (sorted?) there will be little if any capacity difference. You're not worried about capacity when loading it's about what it is when fired. As soon as pressure builds both cases will expand to fit the chamber. I was doing some final load testing over chrono today, some brass virgin and some 1X fired. Couldn't see any difference. I did keep them seperated but I saw no difference in speed and the POI relative to POA was same. That's why you measure h2o capacity after firing not after sizing or with virgin brass.
Same batch/lot of brass (sorted?) there will be little if any capacity difference. You're not worried about capacity when loading it's about what it is when fired. As soon as pressure builds both cases will expand to fit the chamber. I was doing some final load testing over chrono today, some brass virgin and some 1X fired. Couldn't see any difference. I did keep them seperated but I saw no difference in speed and the POI relative to POA was same. That's why you measure h2o capacity after firing not after sizing or with virgin brass.
Re: Case volume difference: new vs FL sized
What kind of volume are you getting?
I got 53.6gr for win and 54.7 for LC 09 brass.
I'm plugging the primer hole with putty then weighing by adding water to the brass.
Interesting that LC has more capacity.
What kind of volume are you getting?
I got 53.6gr for win and 54.7 for LC 09 brass.
I'm plugging the primer hole with putty then weighing by adding water to the brass.
Interesting that LC has more capacity.
Re: Case volume difference: new vs FL sized
For my 308, Winchester brass averages 57.60 and FGMM 55.24. Measured 10 each after firing with spent primer in place and averaged the number. Winchester is weight sorted and saw very little variation in h2o capacity. FGMM was not sorted, it had a little more variation but wasn't terrible.
For my 308, Winchester brass averages 57.60 and FGMM 55.24. Measured 10 each after firing with spent primer in place and averaged the number. Winchester is weight sorted and saw very little variation in h2o capacity. FGMM was not sorted, it had a little more variation but wasn't terrible.
