I think he means, as I do, if belt headspace on the cases is .217", set barrel back so it's chamber belt headspace is the same or .001" greater.
7mm mag case sizing
- Thread starter BW64
- Start date
Ok so I measure from the bottom of the belt not the base of the case to the shoulder??
You car correct. But using a belted go gauge makes the stretching worst.
Here is a pic of one of my belted cases fired 10+ times, then cut lengthwise to inspect for head stretching. Proof is in the pudding.
Using a dremel to dissect a case is not the prettiest way of doing it but does the job.
Belted case headspace is measured from case head to front edge of the belt. .220 - .008 inch is the norm. Most new cases are in the .217 to .219 range.
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Put up a picture marked where the stretching is. I don't see it.
Later...
My mistake, I now see no stretching signs.
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Are you going to adjust your full length sizing die so resized fired cases chamber that way?
I think it's best to size them 1 to 2 thousandths more. Better accuracy if the bolt just closes freely without binding.
Do you have a tool to measure case head to shoulder that's about 2.045"?
I have the Hornady headspace gauge with the seven Magnum insert but that doesn't go all the way down to the point of the shoulder
Attachments
That's the point of the picture I put up. There is no stretching at all after 10+ reloads when I set my own headspace with commercial brass instead of go-no-go-gauges.
The reference point on the case shoulder is its .420" diameter location about in the middle of the sloping shoulder.
Not where the shoulder curves back onto the case body.
Go to page 44 in ...
http://www.saami.org/specifications_and_information/publications/download/Z299-4_ANSI-SAAMI_CFR.pdf
... to see actual dimension specs.
Not where the shoulder curves back onto the case body.
Go to page 44 in ...
http://www.saami.org/specifications_and_information/publications/download/Z299-4_ANSI-SAAMI_CFR.pdf
... to see actual dimension specs.
Always check with a piece of tape on the base of the gauge/case being use to set HS.
Sometimes if there is excessive HS, you can try loading a mild load with the bullets jammed hard in the rifling for the first firing of the brass. This will mitigate most of the brass stretching above the belt.
Even if HS is spot on, I always load the first firing of the brass in the lands to make sure it stretches more evenly. This is with belted and non-belted cases.
For the first firing all we're doing is fireforming the brass anyways so why not.
Never heard of that .004" thick "tape on the base" thing using a case headspace guage. Must not be popular, helpful nor mandatory. Especially because no such tools instructions mention it.
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Sounds like something moved. Remove the ejector (very easily done on Savage bolts) to have most positive feel.
Best part about the Savages is being able to set and re-set the headspace at home.
Someone will read your post and thing you're serious lol
They'll be better off if they do.
Why measure anything to .001" tolerance with a rubber shim that compresses more than .002" under load?
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