Redding Full Length Sizing Die Question

[svana]

I've got a Redding FL type S die (.308) that I started prepping brass with. I've got a Wilson case trimmer with the "new" 308 brass case bushing per Wilsons information (full length sized brass uses the same bushing as new). When I slid the brass into the bushing, it didn't fit.

Long story short, the shoulders are wider than an unfired manufactured round (.453" sized vs .450" unfired). I've tried sizing without the bushing, without the expander ball inside (just the body die), and adjusting the overall depth but it didn't affect the shoulder width any more. Does anybody have a similar setup that had the same problem? It's still within spec (.454") and they were fire formed to my rifle (bolt-action), but my understanding was that it should've brought it to unfired spec.


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[DaemonAssassin]

I've been doing some thinking about this, since we spoke yesterday and I am still scratching my head. Sorry buddy, but I have nothing right now.

 

[atblis]

The dimensions of a factory loaded round are more or less meaningless. Go by the SAAMI drawing. If the die gets it inside SAAMI specs, it's doing its job.

 

[Blacksmith101]

Here is the SAAMI Drawing. Looks like the die is doing a better job than the manufacturer.
http://www.saami.org/pubresources/cc_drawings/Rifle/308 Winchester.pdf

 

[svana]

I've been doing some thinking about this, since we spoke yesterday and I am still scratching my head. Sorry buddy, but I have nothing right now.

No worries, figured it couldn't hurt to get a couple more heads thinking it over.

Here is the SAAMI Drawing. Looks like the die is doing a better job than the manufacturer.
http://www.saami.org/pubresources/cc_drawings/Rifle/308 Winchester.pdf

Ya, it's within spec. The only reason I expected it to be slimmer was because my understanding is that it was supposed to fit in the Wilson "new" 308 case holder. I'll pick up the "fired" holder, just wanted to make sure I wasn't missing something...

 

[svana]

So in theory if you're just neck sizing fired brass from your rifle, the brass could be larger than SAAMI spec but still fit your chamber - right?

 

[DaemonAssassin]

No worries, figured it couldn't hurt to get a couple more heads thinking it over.



Ya, it's within spec. The only reason I expected it to be slimmer was because my understanding is that it was supposed to fit in the Wilson "new" 308 case holder. I'll pick up the "fired" holder, just wanted to make sure I wasn't missing something...

I take no offense, my friend. I don't know everything, and I am actually happy you posted this, because if somebody does know the answer, we can all gain that knowledge. Nothing ventured, nothing gained.

If it is within spec, I generally leave it alone. Don't try to fix what isn't broke.

 

[DaemonAssassin]

So in theory if you're just neck sizing, the brass could be larger than SAAMI spec but still fit your chamber - right?

It depends on how close to spec your chamber is...

 

[Blacksmith101]

In real life unless you have access to a shadow graph or CMM that dimension is impossible to measure. According to SAAMI that dimension is to the point where two straight lines would intersect however in real life there is a small radius there in the real brass case so the intersecting point only exists in theory.

 

[DoctorBob]

To clarify, there are 3 case sizes a reloader has to deal with.
A new unfired cartridge case will be the smallest. It is only
this small once. After it is fired it will never be that small again
unless you use a VERY small FL Die. I know of none made this way.
The largest size of a particular case, that was fired in your chamber,
is the largest dimension it will expand too. In the middle is the case
size after you have FL sized it. All sizes are relative, your chamber
is machined different than mine, new Lapua cases are different
than Remington cases, etc. The comment by “atblis” is exactly right.
I don’t have a certain answer, but I do have a few things to check.
Are you sure you are bumping the shoulder only .001 - .002” after
having done the FL sizing, and no more? Can you re chamber one
of your freshly FL sized cases back into your chamber, with proper
bolt closure? A properly sized case, when chambered, should offer
only a ounce or two of finger pressure on the bolt. This is checked
with the firing pin assy out of the bolt, thus only the lugs are providing
the resistance you feel. If the case is not put into the FL die deep
enough it will be both too long and the body / shoulder junction
will not be compressed enough. Hence your old .454” measurement
may well decrease to .452”, with proper FL sizing, and that likely will
allow the case to chamber properly. For reference, you have already
proved a new case (.450”) will chamber. Dr. Bob

 

[Seabee]

Dr Bob +1
Also, maybe you just need to use the Wilson case holder for fired brass even though yours is sized. I've had to do that myself.

Ken