Case length


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ny32182
January 10, 2008, 11:50 AM
I'm just getting started reloading, and I'm prepping some .223 and .308 cases for the first time.

So far I've tumbled->sized->tumbled, and then checked case lengths. They are all coming up over maximum and look like they will need to be trimmed. Is this normal for once fired and FL resized brass? I was under the impression it would take at least 3 firing and resizing cycles to get them over length... Thanks,

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The Bushmaster
January 10, 2008, 12:27 PM
Brass and ammunition manufacturers are not that careful about OAL and as long as they are within specification it's a go. When you trim them back to minimum length some will need retriming after the second reloading and some will not. A lot depends on how hot you load them. It also depends on the die and the lube you use. Neck sizing should minumize stretching of the case...Case length is important on bottle necked rifle cases...Too long and you will force the case into the rifling and have a very high and dangerous pressure spike...

Mark whiz
January 10, 2008, 12:34 PM
That is not too surprising, especially if those cases came out of a semi-auto.
Now is a good time to get the whole batch trimmed to the same length, so all you loads will start with that known quantity.

When loading for my M1A or Win Model100 semi, I find I usually have to trim after 2 or 3 reloads. I also anneal the cases after 3 to 6 reloads to keep the brass pliable for proper resizing and case life.

ny32182
January 11, 2008, 01:09 PM
Well I got the trimmer fired up last night and trimmed, chamfered, and deburred 100 .223 cases and 22 .308 cases.

Man that takes some time. I hope that doesn't have to be done after every single firing.

I trimmed them to about .001" over the listed "trim to" length. I checked each length as they came off the trimmer, and then spot checked lengths after chamfer/deburring. I'd say the extreme spread was .003", with the vast majority of them right at the .001" over minimum that I planned for. Hope thats alright.

Tonight I get to try some primer pocket cleaning/swaging, as my tools for doing that are scheduled to get here today.

SASS#23149
January 11, 2008, 01:36 PM
The mandrel type of sizing dies are suppposed to all but eliminate the trimming chore,you might want to consider one of those.
One thing that will stretch the case out is the expander ball grabbing the inside of the neck as it's drawn out of the case.I changed to a mandrel type die and life got a lot easier.

The Bushmaster
January 12, 2008, 11:36 AM
ny32182...Trim, debur, chamfer THEN measure for length...

ny32182
January 12, 2008, 04:22 PM
I did spot check a number of them after chamfer/deburring, and the were almost all coming up exactly at my intended length.

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