reloading .223

[Mark Bellon]

I'm new to rifle ammunition reloading and I'd like to get some insight from those with more experience.

I've got some .223 once fired brass - fired it myself. I did some measurements and see that the brass length is all over the place, anywhere from 1.7495 to 1.762. I expected that, as they're going to stretch when fired. What I notice is that all of the cases measure up differently when I rotate them, sometimes by as much as 0.003. Is this normal?

Seems like I need to trim to 0.001 over my goal as chamfering and deburring cause the length to go down slightly. None-the-less I see the same slight variations in length when I rotate the cases, albeit they are now less than 0.001. Is this normal?

Is there a suggested way to measure case length given the rotational variation? Are the short cases problematic for reuse (0.0005 below the target of 1.750)? Any trimming, chamfering and deburring recommendations?

Thanks!

mark

[Chills1994]

Forum search results for my screenname plus the word "possum"

[Hammar]

Make sure you resize them before trimming. The trimming process should even things out at the case mouth.

[Ken Kwiat]

I'm not surprised that you will see variations in length after firing in an AR. If you think of what's causing the lengthening (essentially extraction while the brass is very heated), there are variables at play. I don't think the rotational variation makes any difference other than an interesting observation as you should be full length re-sizing and trimming to get everything back to spec (for semi autos, bolt guns have different characteristics). Similiar to what Hammar said, I FL resize then trim/chamfer with a Giraud trimmer to 1.750". The Giraud is a very good trimmer but there are plenty others out there that work well (Dillon's for example). Note: I trim after every firing and I believe most 3-gun shooters do as well. I have heard that some get away with every other firing or so. For me, I want consistency (within reason of the time/benefit tradeoff).

There are measuring tools for concentricity, neck wall thickness, and all sorts of of other stuff. For example check out Sinclair International's catalog. They are targeted more towards the benchrest crowd as they run through all sorts of gymnastics in brass prep since they're trying to eliminate all variables. This is way overkill, imo, for our sport. I spend much less time in case prep for .223 (for 3-gun) than I do for LR tactical shooting.

.0005" shorter? Shouldn't be a problem at all assuming you're getting the COAL desired. It likely will be longer than 1.750" after the next firing.

[jmurch]

IMO: Size, trim, and load.

You're not shooting 1000 yds with 90grn bullets. Practice is worth way more than trying to load perfect ammo.

Jeff