Brass sizing question

jacky

jacky

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I was looking over some of my 7mm mag brass that I reload and noticed a "ring" or " band" just above the belt on the case. Now my sizing die is set such that there is a penny's width between the top of the die and the case holder when resizing. I always thought I was neck sizing only by doing this but now I think I was wrong given that band on my case. Some of my brass has been reloaded 3 times and it works great and is not stretched a ton.

Is the band something to worry about ??

Can I set my sizing die to neck size only ??

Thanks
 
I'm not the expert you're looking for but since no one else is answering, I'll give her a go.

My RCBS concentricity gauge setup came with instructions on how to detect a problem which you may have starting, case head separation. The RCBS gauge has a probe with a hooked tip that, inserted into the case mouth and in conjunction with the gauge itself measures brass thickness/uniformity in the region just forward of the case head. In advance of failure in that area there apparently develops a ring of thinning of the case wall. The gauge will identify this ring as a groove. You may be seeing visual evidence of the same thing. This is just my inexperienced guess but I'd be careful until I eliminated this as a problem if I were you.

To neck size brass, you need a neck sizing / bushing die. Redding makes em. No doubt others make em too.
 
First off, you are partially full length sizing not neck sizing. You are going to see a frosty wear pattern on the body of the case. Since you are PFL sizing case head separation should be a non-issue. As long your ammo is chambering easily, I wouldn't worry about it.
Many magnum chambers are cut sloppy, and there is a limit to how far the die reaches to the bottom on the case. This can leave a raised ridge above the belt. As long as the cases still chamber easily, it doesn't matter.
 
Take a bent paper clip, and scrape along the inside of the case. If you feel a ridge, where the ring is, then the brass may be pooched. Lots of my 300wm, and some of my 22-250 cases have the ring, but none have any ridge that I can feel, so I keep using them. I mainly just try to size the neck, as they are both for bolt actions. Some of my cases have been fired 4 times, and all are still going strong.
 
Case Sizing

It sounds like you are setting the shoulder back each time you resize. This can lead to early case separation. Magnum cases do not reliably headspace on the belt. Set your dies so the cases headspace on the shoulder.:)
 
"...there is a penny's width between the top of the die and the case holder..." Too much. The shell holder should just kiss bottom of the die with the ram all the way up.
 
If you are partial full length sizing you shouldn't be setting the shoulder back--the marks are normal on the case but it doesn't hurt to chech occasionally with the bent paper clip for a separation--also if you suspect an impending separation--section a case or two to actually check.

44Bore
 
Well first I have never had a problem chambering a cartridge. I shoot a Tikka M685 Deluxe and it has a long chamber so I even seat my bullets a little less than normal ( giving a longer overall length ) and I get some unreal accuracy. No problems feeding or chambering. The paper clip idea is good and I will try it but just out of interest how do I set my dies so they headspace on the shoulder ??
 
Accurate Resizing ....

Jacky,
Reloading any belted magnum caliber requires a bit more information than reloading non-belted calibers. Factory ammo headspaces on the belt. However, handloads should ALWAYS be headspaced on the shoulder.

The first firing of a belted case causes case serious stretching. It weakens the case, making belted cases more prone to separation. I recommend using a full length resizing die, because it's a good idea to push the shoulder back .002" for 100% reliable chambering. HOWEVER, if you bump the shellholder into your resizing die, you'll definitely push the shoulder back too far, and that will CAUSE problems . . . . . . including the "band" on your case. That will soon lead to headspace separation.

Our Digital Headspace Gauge (below) compares your handloads to one of your fired cases. Then it displays the exact clearance that YOUR handloads have in YOUR particular chamber. You can then set your die height perfectly.

COAD-06SM.jpg

I also designed a special collet resizing die that properly resizes the body of almost ANY belted magnum case. The top of this die is a case width gauge that shows when a little extra resizing is needed. Our Belted Magnum Collet Resizing Die ensures reliable chambering, and it extends the life of your brass by quite a bit. It also works on 20 different belted calibers.

diesmall.jpg

You can read all about these products on our website. Visit WWW.LARRYWILLIS.COM

- Innovative
 
Larry,
great stuff, but does the handload not also have to be a fired case so that the platform that fits around the shoulder of the case that is being measured, is measuring from a known point?

Sorry, I'm a bit thick sometimes.
 
Oh no I think I got it. Use the DTI on a fired case to get the known point. Then size other brass similarly. Thats my guess anyway.

EDIT: but no will all other brass stop that platform at exactly the same place?
 
Innovative,

Nice stuff but all my loads chamber smooth and I have never had a problem. I will move my resizing die up a hair so that the shellholder "kisses" the die and see what it looks like.
 
jacky said:
Innovative,

Nice stuff but all my loads chamber smooth and I have never had a problem. I will move my resizing die up a hair so that the shellholder "kisses" the die and see what it looks like.
Click to expand...

They will chamber smoothly if you are bumping the shoulder back. If you're trying to neck size only, there should be a very slight resistence on chambering. Note I said very slight, not much at all...
 
Jacky,
If you look at Blacksmithden's pictures you will see a lot of things. First you can see the line where the die stops sizing the case. You can see the line from incipent separation, and if you look closely at the last blown up picture you can see a real nice false belt forming above the belt on two of the cases.
What exactly is it that you are seeing on your cases? While I don't deny that we hounds are having fun barking up three different trees, I doubt that it is helping you much.:D
My bet's on the false belt, slightly higher than the one in the picture.
 
Here are my cases. I don't think they are that bad after looking at those other ones. These have been reloaded three times and now I am on my fourth.

April-June001.jpg


April-June003.jpg
 
Judging from your picture you have nothing to worry about. One of these days you will likely have to bump the shoulder back when chambering gets tough, but that's a different issue. Nothing that a match and a couple minutes won't take care of.
 
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