Sizing Die Adjustment - Needed??

[Bitis Arietans]

I need some help. I've been hand loading for several years, but I'm still learning. I have found some info on your site...but need to get a better understanding.
I am loading for a friend's 7 MM Rem Mag. (I have one as well). I used new brass for my first loads. After sizing this fired brass, it will not chamber well, it's very tight, difficult to close the bolt.
The sized brass chambers just fine in my 7MM. What to do?? Perhaps the sizing die requires adjustment? Here's where my experience starts to fail!
I set the die the way I always do...run the shell hold up to the sizing die, and then tighten 1/4 turn.
Been playing with this problem for almost 2 days.

Please tell me where I'm going wrong.

 

[Dosh]

B, no two chambers are the same. Sounds like you're brass is mixed together. If his brass doesn't fit yours or yours doesn't fit his, that is common. Keep your brass separate of his. To bump the shoulder, the die must be closer to the shell holder and the press "cam over". See You-Tube for visual demo. Good luck

 

[Bitis Arietans]

Dosh...I guess what I'm struggling with is that, I'm thinking as soon as I FL Size the case I'm back to where I need to be with any rifle. I started with new brass with HIS rifle. FL sized it and it won't chamber in HIS rifle...It's very tight...you can slam the bolt down, but that's not where I'd like to be with a hunting rifle
Any thoughts? Thanks much for your reply!!

 

[bigedp51]

Dies and chambers vary in size, meaning in diameter and headspace length.

If you measure the cases after they are fired with a Hornady cartridge case headspace gauge you will know how far to bump the shoulders back.

Below measuring a fired case from my AR15 carbine and after full length sizing the case measured 1.464 or .003 shoulder bump.

During sizing the brass has only one direction to move and that is upward and the case shoulder location is squeezed forward. And on a bolt action you want to push the shoulder back .001 to .002 below the "red" the dotted line.

There are two possibilities with your tight fitting belted case.
1. The shoulder is not being pushed back far enough.
2. The case was not sized enough just above the belt.

Blacken the problem case with a felt tip marker and chamber the empty case and see where the black marker has rubbed off.

If the shoulder has rub marks you might have to lap the top of the shell holder. This will allow the case to be pushed further into the die for more shoulder bump.

If the rub marks are just above the belt you may need a belted collet die.
Belted Magnum Collet Resizing Die
Innovative Technologies - Reloading Equipment

 

[Bitis Arietans]

Big Ed...Gonna digest what you have sent me...I have never really considered the issues that you have raised as I've been loading for newer rifles, that have been well cared for. I suspect my buddy's rifle has a sloppy chamber and the cases have been fire formed larger? I figured that after the sizing procedure...you are kind of back to where it should be...

 

[Dosh]

B, while you're at it, measure the case length. They should not be more than 2.48" and all should be trimmed and de-blurred to the same exact length to maximize accuracy. Hope its the shoulder or case length causing the tightness. Good luck

 

[WildRose]

Dosh...I guess what I'm struggling with is that, I'm thinking as soon as I FL Size the case I'm back to where I need to be with any rifle. I started with new brass with HIS rifle. FL sized it and it won't chamber in HIS rifle...It's very tight...you can slam the bolt down, but that's not where I'd like to be with a hunting rifle
Any thoughts? Thanks much for your reply!!

It all depends on how you have your sizing die set up.

To start, do no use brass fired in your rifle for his, only use his brass for his rifle.

Try a piece of the once fired brass before you resize it and see if it chambers and extracts easily in his rifle and then go from there.

 

[nmbarta]

Make sure your setting the bullet off the lands, jamming the lands could cause this problem and cause pressure issues as well.

If your fl sizing with the method you described and your not bumping the shoulder, either the chamber or the die is out of spec.

Is this a custom rifle/barrel? If so, who did the work?

Setting up the die the way to are should set the shoulder back farther than you need to, and can over work the brass. If you don't have the tools to measure the shoulder, you can try a piece of 9mm brass, it won't give you a perfect measurement, but should give you enough to know if your moving the shoulder.

 

[Bitis Arietans]

Hey Nm / W Rose- the bullet isn't seated as yet. I started with new brass. Shot the rifle. FL sized the brass, setting the sizing die, as I always do. Screwing down the die to touch the shell holder, then screwing down about 1/8-1/4 turn, to take the play out. I loaded the once fired brass, (fired in this same rifle) and the cartridges were tight. I fired them, although the bolt was tight, (Not banging down the bolt tight). I proceeded to size them again, the same way.
This time I'm checking the sized brass in the rifle before loading them.
They are tight!

Is it possible that I shouldn't size them? as they are fire formed? I'm at a loss!

I have done the "Sharpie thing" and I see a faint mark in the middle of the shoulder, and faint scuffing at the bottom of the case, just above the belt

 

[Dosh]

B, while you're at it, measure the case length. They should not be more than 2.48" and all should be trimmed and de-blurred to the same exact length to maximize accuracy. Hope its the shoulder or case length causing the tightness. Good luck

Did you measure?

 

[Bitis Arietans]

Hey D

Yeah I did... The Barnes Handbook says the case length is 2.500" and trim to 2.490"...but I did as you said a went to 2.480" and no change.

It may be the shoulder, but I did the Sharpie paint test
The result showed some light scuffing on the case just above the belt., and some faint marks around the center of the shoulder...neither case seem to be the cause for such a tight "bolt closing".

I will start with new brass. ..But after the new case fire forming, Should I not resize the case?...I'm lost.

 

[WildRose]

Hey D

Yeah I did... The Barnes Handbook says the case length is 2.500" and trim to 2.490"...but I did as you said a went to 2.480" and no change.

It may be the shoulder, but I did the Sharpie paint test
The result showed some light scuffing on the case just above the belt., and some faint marks around the center of the shoulder...neither case seem to be the cause for such a tight "bolt closing".

I will start with new brass. ..But after the new case fire forming, Should I not resize the case?...I'm lost.

As a rule I only neck size my brass unless it grows enough to start being a little snug and then I'll full length resize.

Depending on the rifle and the caliber that may be every third, fourth, or fifth firing.

Most people find that your best accuracy and consistency comes from neck sized brass rather than full length resized brass.

If all you have is a full length resizing die you can partially full length resize and get nearly the same results. To do this you back your resizing die off a good bit and smoke the neck and shoulder area then work it through the die slowly lowering the die until it just almost shows to be working the brass to the base of the neck.

I did this for many years with .220 Swift, 7mm RM, and 7mm STW because I was just on a shoestring budget and couldn't at that time justify buying a neck sizer die for each of them.

Another benefit is that the more frequently you full length resize the quicker you'll wear your brass out and I find that neck sized only brass gives me considerably better case life.

 

[bigedp51]

Full length resizing does not shorten case life when done properly with minimum shoulder bump.
Please note the post below and "who" wrote it.

Also I would measure the shell holder for proper deck height and if needed lap the top of a shell holder to push the case further into the die. Just remember to mark the shell holder and keep the lapped shell holder separate from your standard shell holder.

Also remember rifle chambers and dies vary in size, I have a standard Lee FL die that reduces the case diameter more than a small base die does.

 

[Bitis Arietans]

Thanks Big Ed, W Rose, Dosh and all of the folks that have contributed!
The problem that I am having difficulty understanding is ...

Why doesn't a case that I have FL Sized (that started as new brass, shot only once in the same rifle) not chamber well (tight)??

In my way of thinking... we resize the case to get it back to spec, Yes?

I've "markered-up" the case... and after chambering the case, No "significant" marks were seen.
I must get a head space gage...I guess... and check what is happening after the round is fired in this rifle.

I think that I must now learn that the Sizing Die can be adjusted somewhat.

I have loaded for 2 different 30.06's and never changed the way I set the Sizing Die...so, if I understand.. Just setting the Die per RCBS: "Screw down the die to till it contacts the shell holder, then down a 1/8 to 1/4 turn" is a one size fits all approach?

The BUMPING of the neck is what I have to play with and understand better.

The graphics that Big Ed posted makes it much clearer...I think doing it may be another matter

I will keep at it after I make a couple of purchases to get the head space tools.
I will likely reach out again soon.

I heard NS Dies increase brass life also...so I bought them for all of my calibers...but abandoned them after a NS round wound chamber in my Dakota Mod, 10 Falling Block