Winchester Brass - Reloading

Another question for all you shooters... I sure like this place.... As you know i have been shooting my Savage 300 win mag using Winchester brass and IMR 4350 (69.0gr) and Federal 215M primers with some good results....

Purpose of this thread is does anyone have any issues with measuring up the COAL with Winchester brass???? i use a Mitutoyo Caliper #500-196-20 and the Hornady comparator and measuring from the base of the case you never get the same reading...

I notice that from the very begining... to tell ya my procedure for reloading is not nearly as intense as some since this really is a factory huting rifle except for the replacement stock i have on.

I square up the primer pockets, debur in/out flash hole, full length size the brass with a forester die(only new brass) if its fired brass i only neck size using redding dies and then i trim to length, deburr the necks in/out, i use a redding competition seating die and i try to mic up each case to exactness. see nothing too crazy in my process.

The biggest probelm i found is that the brass base is never flat. I know they are punch out on a machine, but damn, they are out .002-.004.. so i tyically just have a range of what my actual COAL is... my rifle using the nosler 168BT, touch at 2.931 using the Hornady guage, and shooting them they like its at 2.920-2.925 with the hornady comparator. so when i mic it up,its some where in that bull park... i just thought you buy Winchester brass and your good to go.... guess not.

what can you do to the bras to fix it the basses for a much for exact measurement.

It's not just Winchester, I had to resize Lapua and check the OAL, some I had to trim. I was told to do this with any new brass, whatever the brand is!

yes, trimming the necks is yes a thing you must do... I was asking bout the base of the cases..... none of them are truely FLAT/SQR..

so you never get a consistant measurment..

Sometimes the stamping of the brand name of the brass will give you inconsistent readings as well.

With 600 grit sandpaper, remove the raised portions.

First,try a half dozen or so bullets in the comparator,to see how consistant they are.Some of your +/- COAL could be there.I can believe the bases not being square,but I would think they would form after one or two firings.One thing I've found on winchester brass is off-centered flash holes, on about 8-10% of the cases.

has any one ever put a brass case in a lathe and took a very light skim cut on the base
to really see how much they are not square?

Well sometimes is not what we're measuring, but how we're measuring it.

Runout or not you need a method to measure the same thing your shellholder saw sizing -seating, the longest point of any runout. If a piece of brass has .005" case head runout thats the point it will rest on sizing-seating. So, the most accurate and consistent way to measure it is the same way time after time.

http://i43.tinypic.com/f0zsrp.jpg http://i40.tinypic.com/2na7cqb.jpg

The second bushing duplicates where the casehead contacted the shellholder during the sizing-seating operations including any variation around the primer pocket. It also ensures the case is always aligned consistently. The bushing is bored exactly .100"deep , so you can add .100" to the measurement for a real number if you want.

You might be surprised just how consistent your ammo is already.


Oh, to align the two bushing holders to be sure they're square....
http://i39.tinypic.com/2rz89ro.jpg


Bill

Quote:

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Originally Posted by MatthewUSMC8791

perfect.. that is EXACTLY what i was talking about..... where do i find the other half of that comparator to put the base of the case in?????

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I don't know where you'd find them, I made the three I have, one each .378", .470" and .532".

Bill

i only need one for the 300 win mag brass...

>>>
i only neck size
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I'm hoping this is not a hunting rifle?

Regards,
Brian in CA