Sticky cases

[Britz]

How can you use the compatition holders to increase headspace? The holders are designed to make the cartidges longer from base to sholder by .002, .004, .006... more than the standard shellholder. I'm not trying to be a smart A, maybe I am missing something -- that wouldn't be a first

 

[rick smith]

From the Redding catalog "Each shellholder has a distinct black oxide finish and is clearly marked to indicate the amount it will Decrease case-to- chamber headspace."Rick.

 

[kraky]

Rick...it's all about how you think about it. I think they are saying if you have .010" too much headspace in your chamber you will reduce the headspace problem by making the shell longer as you size. (It reduces the amount of excess headspace) If you take a caliper and check the thickness of the shellholder they get thicker as you go up in numbers.

 

[rick smith]

That is why you start with the + 0.010 and then use the + 0.008--- to decrease the headspace of the case. This may be a discussion of the glass half full or half empty. I realize they may be used in either direction but if you start with the +0.002 and go to the +0.010, you are not going to get the case to grow that much. As I quoted from the Redding catalog, they are to help the loader "decrease case-to-chamber headspace".
I also think that if you grind the top of a shellholder, it should be kept as straight as possible if the shellholder is making contact with the base of the sizing die. We go to great lengths to keep our cases as uniform as possible and runout as low as possible. If you put an uneven shellholder in contact with the base of a sizing die something is not going to be in alinement. There is enough mechanical advantage in a press to bend the brass out of concentricity.
Not trying to go to war with you. Just trying to show why the Redding competition shellholders will work as advertised and as they were designed.Rick.

 

[lmerickson]

Well in my case it doesn't matter either way because the shell holder can hit the bottom of the die and still not get enough sizing due to the fact that the shell that the gunsmith just made the chamber a little to tight. SO now the question is.....have the chamber reamed out a little more...... or take my resizing die and bring it to a machine shop and have them put it in the lathe and take a little off. Opinions???? It shoots extremely well right now, just can only use the brass once.

 

[SakoSteve270wsm]

Shell holders are cheaper than dies,if you are going to grind/machine I would do it to the shell holder.

 

[JungleJim]

Redding competition shell holders won't solve this problem. They are designed to increase head space to keep shoulders from being pushed to far back increasing head space. They have the same effect as adding appropriate amount of shim stock between shell holder and base of the die when setting up.

A standard shell holder has a pocket .125 deep. This is standard for all shell holders in rifle cartridges in the US.

A .002, .004, .006, .008, .010 Redding shell holder means the shell holder pocket is now .127, .129, .131, .133, and .135 deep.

To fix the problem of not enough head space when FL resizing. Either you can roll the dice a get another brand of FL die sometimes it works. Went from a RCBS FL die to a Redding FL die on one application and the problem went away. Or you can take your die to a GOOD machinist have him take .010 -.015 off the bottom of the die on a lathe after indicating it in dead nuts. Than use Redding competition shell holders or shim stock to readjust the desired head space when setting up.

 

[Britz]

go get two shell holders from the gunshop and some sandpaper from the hardware store (I want to say 400 grit, but I'm not sure). place the sandpaper on a good countertop or something very flat. Take a measurement of the shellholder and commence sanding in a figure 8 fassion for 10 strokes. twist the shelholder 1/4 turn and continue the process until you get to the desired dimension. When or if you screw one up, you can fix the other shelholder that you purchased and save yourself a trip to the store.
happy sanding, Mark

 

[lmerickson]

I have already started working on the shell holder. By the time I would get down to the needed size I'm thinking I may run into trouble with durability of the shell holder. I have tried the RCBS die and Forester die. Does anybody have a redding die in 7mm RUM. If the dimensions go smaller I'll order one otherwise I may gamble and get my current sizer die worked on.

 

[rick smith]

I stand corrected on the competition shellholders as to their size, thank you Jungle Jim. They will not work in the current presented problem. They will work with the belted mags as advertised. The reason is loaders headspacing on the shoulder and not the belt. I just measured the difference in a 7mm Mag unfired case vs a case from the same lot of brass fired in a Ruger 7 Mag. 0.020". If I used a standard shell holder with a FL die to size, using the directions of shellholder against the bottom of the die at full ram height, I would probably set the shoulder way too far back. That is when the competition shellholders can be a help.
Imerickson, FL dies are hardened so it may cost less to return the die to the manufacturer for a change if you choose that route. When you try the shellholder you are sanding use a different case each time you size.Rick.

 

[kraky]

I just checked the shellholder I ground off to work with a friends 300 rum. Looks like I took off about .014" as this one now measures .231 thick and it probably started about .245. It works perfect now and doesn't bump the bottom of the die. I thought the original poster only needed about another .002" bump????
Sandpaper would take forever....hit the grinder wheel....it works.

 

[lmerickson]

Well I went to a local machine shop. I got everything in working order again. Thanks for everybody's help. I hope this may help other people that may have a similar problem. The machinist took off about 50 thousandths, a little more than what I needed but everything seems to work fine. Can't wait to get to the range. Gotta get some ballistics data this weekend. Once again thanks!!!!!

 

[rickt300]

If fired factory ammo can be chambered before resizing then something you are doing while sizing is causing the problem. I normally don't try to push the shoulder back any and don't mind using some pressure to get the bolt down. If you ar pushing the shoulder back too much there may be a bulge just behind the shoulder. You may need another set of dies and it sounds like your chamber might be a bit rough. Another thing, judging the pressure you are getting by your bullet speed is a flawed system. You could be getting much higher pressures than you think, not all rifles and barrels perform identically. I prefer to judge by sticky extraction, case head deformatian and primer appearance.

 

[lmerickson]

Factory ammo could be chambered before resizing. And I have already tried purchasing another die thinking that would maybe fix it.....it didn't. The measurement of the case after being fired is smaller than either of the dies can resize to.

 

[Britz]

It's been a long time since I've loaded for an automatic, but isn't there a Small base die that sized brass to slightly less than spec? If so, would that possibly work for you?

After I initially posted this, I felt a little stupid and looked at RCBS's website. They offer the Small base die in some cartridges but apparently not the 7 RUM.