FL sizing 7mm

[Rogmay]

I have a tikka 7mm that I have always necked sized, have just over 200 cases, have 5-6 firings on each case and they're stating to get a little heavy bolt opening and closing, so I was planning on running them through the FL die. I also have a Cooper 7mm that has a smaller chamber and those cases go right in with ease, the only measureable difference I can see is at the shoulder, about .003-.004, but when I run them through the die it's not bumping them back at all, any suggestions as to why this is would be greatly appreciated, thanks in advance for your suggestions.

 

[RockyMtnMT]

I think you are saying that when you full length size it is not bumping the shoulder enough to get rid of the crush fit in one rifle but it is good for the other?

Are you camming over when you size? How many shots on the brass? It may need to be annealed.

Steve

 

[codyadams]

Either that, or your chamber is tight enough that when you run your ram all the way up against your die, it's still not bumping the shoulder. I had this in a Remington .308 with a stupid tight chamber, I had to use a small base die to size it enough to fit, it wasn't just the shoulder area that was tight.

If your die isn't sizing enough, you can get a new shell holder and measure it, and use a diamond stone to remove about .005" of material off the top at a time until you begin to bump the shoulder. Put that shell holder in your die box, specifically for that rifle. Essentially what your doing is letting your press push your brass farther up into your die, allowing proper sizing for that rifle.

I believe there are adjustable shell holder kits as well to resolve this issue, but I haven't used them, because I had enough shell holders laying around that I could spare one for a rifle, and it was quicker and cheaper than ordering one.

 

[TwoMore]

I have had to take a lil off the bottom of a die on a couple to get the correct bump but you have to remember on a longer chambered rifle you wont feel the camover on that brass when it bumps the shoulder, I now have three 7 WSMs but each one has its own sizer, one of them is factory and its chamber is sloppy big lol

 

[J E Custom]

I have a tikka 7mm that I have always necked sized, have just over 200 cases, have 5-6 firings on each case and they're stating to get a little heavy bolt opening and closing, so I was planning on running them through the FL die. I also have a Cooper 7mm that has a smaller chamber and those cases go right in with ease, the only measureable difference I can see is at the shoulder, about .003-.004, but when I run them through the die it's not bumping them back at all, any suggestions as to why this is would be greatly appreciated, thanks in advance for your suggestions.

A simple way to resolve this is to leave the dies set normally and use a feeler gauge or a shim between the shell holder and the case head.

I like to try feeler gauges first starting with .002 thousandths and do a test sizing to see if it is enough to have the right chamber feel. If it is not I try .003 and so on. (I have never had to add more than .004 or .005 thousandth thick shims to get the desired results).

Once I find the proper gauge thickness, I cut a shim of the same thickness and place it between the shell holder and the case head (Cases must be de primed before the shim can be used) with a touch of grease to hold it in place and proceed sizing all of my cases.

After many firings, cases have more spring back and may need more sizing. By using the shim, it does the job without changing the dies when you need to size new cases. Then I can write the thickness on the shim, and place in the die set for future use.

A neat little trick that does the job and doesn't alter the original setting and/or saves dies that are to large for some chambers.

J E CUSTOM

 

[TwoMore]

I will try that for sure

 

[Rich Coyle]

J E Custom,

Doesn't make any sense. You puting a shim between the shell holder and the die seems counter productive. What I understand you posting is lengthening the die. I have taken a few thousandth off dies to get what I need.

 

[TwoMore]

I may be wrong but I understood it to be between the brass and holder, but I have took some off the die to. my problem is I use a Hornady progressive press but only single stage it. and my shell holder is a bit different

 

[Rogmay]

Awesome reply's guys, a lot of great advise, all cases are already deprimed so I'm going to try the shim between the brass and shell holder and see how that works, once again guys, this is why these sites are here, for all of us to help and get help from everyone, take in what you can and use what you want! I'll post again and let you know the results.

 

[Rogmay]

I think you are saying that when you full length size it is not bumping the shoulder enough to get rid of the crush fit in one rifle but it is good for the other?

Are you camming over when you size? How many shots on the brass? It may need to be annealed.

Steve

RockyMntMt, you are correct when I was not getting the shoulder bumped back enough, I am camming over as well, brass has 5-6 firings on them and annealing might be a good idea!

 

[J E Custom]

J E Custom,

Doesn't make any sense. You puting a shim between the shell holder and the die seems counter productive. What I understand you posting is lengthening the die. I have taken a few thousandth off dies to get what I need.

J E Custom,

Doesn't make any sense. You puting a shim between the shell holder and the die seems counter productive. What I understand you posting is lengthening the die. I have taken a few thousandth off dies to get what I need.

I said between the shell holder and the "Case Head". This save you from grinding on the die body to size or bump the shoulder.

Placing the shim between the shell holder and the case head forces the case farther up inside the die sizing it more and bumping the shoulder
without having to buy another set of special dies or shell holders.

It also gives you infinite Adjustments on different size chambers of the same calibers.

J E CUSTOM

 

[Rich Coyle]

Thanks.

 

[okie man]

5 or 6 firings, things are changing, spend a $100 bucks and start with a new batch of brass

 

[Rich Coyle]

5 or 6 firings, things are changing, spend a $100 bucks and start with a new batch of brass

I must be missing something. Today I fired my Weatherby Mark V .270 Win six lug ultralight at 200 yards to make sure it was sighted in for Saturday's opener. The brass has been used at least ten times and maybe a dozen times or more. The four shot group was 1 3/8" or about .66MOA.