Sizing question, I think?

[limon32]

I've got some .270 brass that was Winchester new and then fired once. I can't recall but I think it was in my old .270. I FL sized it, loaded up a new test batch and they wouldn't chamber. I could get the bolt forward but it would not close with moderate force, I didn't push it beyond that.

I took some pieces that I hadn't loaded yet and measured their length and they were longer than the case length shown in my Lyman manual. I went out and bought a Lee case trimmer and appropriate pilot/shell holder. I just trimmed them up and they measure 6 thousandths under the case length shown in my manual.

I tried to chamber them again (no bullet or primer) and I can now close the bolt but it takes a fair amount of pressure. Way more than factory rounds.

I sized them one more time (after trimming) and the bolt seems to close slightly easier, might be my imagination.

Any thoughts on what's going on here? Are these going to chamber easier after shooting them in the new gun? Are they un-safe?

Thanks in advance!

 

[sh]

Since you trimmed the length, the shoulders might have to be bumped a bit more. Do you have a headspace gauge?
I am thinking you might be trimming too much case length also. I think .001 less than spec would be perfect, not 0.006
When you set your die to resize , move it down in tiny amounts until your brass chambers easily, should be about 0.001-0.002 less than a fired case. ( headspace).

 

[limon32]

Since you trimmed the length, the shoulders might have to be bumped a bit more. Do you have a headspace gauge?
I am thinking you might be trimming too much case length also. I think .001 less than spec would be perfect, not 0.006
When you set your die to resize , move it down in tiny amounts until your brass chambers easily, should be about 0.001-0.002 less than a fired case. ( headspace).

Thanks for the input, I'll double check my sizing die but I think it's as far down as it will go without contacting the shell holder.

As far as the trim length I'm .003 longer than the trim to length that I found in a few references. So I think I'm good there, I think...


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[alaska2go]

try turning the die to where it touches the shell holder when the handle is in the down position. Go to you tube search long range reloading and they will give you all sorts of pointers.

 

[limon32]

try turning the die to where it touches the shell holder when the handle is in the down position. Go to you tube search long range reloading and they will give you all sorts of pointers.

Will do thanks!


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[dkwarthog]

Are you lubing the inside of the case necks? Sometimes the sizer button will pull the shoulder up with it when you pull the button back thru on the way out.

Also, to add to what was already said, to fl size you should screw the die in to touch the shellholder and then another 1/4 to 1/2 turn. That will make sure you get full length sizing.

 

[limon32]

Are you lubing the inside of the case necks? Sometimes the sizer button will pull the shoulder up with it when you pull the button back thru on the way out.

Also, to add to what was already said, to fl size you should screw the die in to touch the shellholder and then another 1/4 to 1/2 turn. That will make sure you get full length sizing.

I have been putting a little lube on the inside of the case neck, I'll try tightening down the sizing die here in a few minutes, thanks!


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[sh]

if you do that

if you do that

Are you lubing the inside of the case necks? Sometimes the sizer button will pull the shoulder up with it when you pull the button back thru on the way out.

Also, to add to what was already said, to fl size you should screw the die in to touch the shellholder and then another 1/4 to 1/2 turn. That will make sure you get full length sizing.

you might be oversizing, creating excessive headspace.

 

[.338WM]

Adjust the die all the way down against the shell holder as dk mentioned, to the point the lever "cams" over lightly. There will be no "excessive headspace" concern, they should then chamber easily and then once fired should never be an issue. Also, be sure the chamber of the rifle is immaculate, a tiny little spec of powder, grime, small piece of cleaning patch, etc., will cause difficulty chambering a round-inspect the shoulder of the brass for the least indentation/deformation for an indication of this.

 

[limon32]

Thanks again fellas, I tightened the sizing die all the way down and now get a little cam over, just a touch. I can now close the bolt on several pieces that I was afraid to before. They are still tighter than brass that's ONLY been through the new gun but at least it closes now. I was taking more measurements just now and noted that the base of the neck on the pieces that are tight are measuring right at the dimension shown in the book (.310) and the pieces that chamber easily measure .306, what are the odds that will work itself out when I fire it in the new gun?

 

[Smitty of the North]

I think you probably need to size the case "All the way".

Sizing can be funny, in that, you can have a fireformed case that chamber's easily, but when you size it "partially", it will NOT chamber. Because, before the case has been fully sized, the shoulder is squeezed, and that causes the shoulder to move forward, and it won't chamber UNTIL you complete the sizing which will move the shoulder back again.

I don't know that this is the case in all, or many situations. It likely depends on the cartridge design, die dimensions, and the rifle chamber dimensions. In any case, your cases must not be getting sized enough. Adjust your die and see if it solves the problem.

Also, if you have a case that is VERY hard to size, (Surely, not a 270) and you are using a press that has a lot of FLEX, the case won't size well. There's a lot more about sizing than meets the eye.

In answer to your other questions, when I make 7mm Rem Mag cases into 7mm Wby, using a 7mm Wby sizing die, in order for the sized cases to chamber, I need to put a feeler gauge under the shell holder, to take out the slop.

Once they are sized enough to chamber they chamber hard, but after I fireform them they are fine, and chamber easily. They do have shorter necks, from the shorter 7 Rem Mag brass, but that creates no problems.

Smitty of the North

 

[limon32]

I think you probably need to size the case "All the way".

Sizing can be funny, in that, you can have a fireformed case that chamber's easily, but when you size it "partially", it will NOT chamber. Because, before the case has been fully sized, the shoulder is squeezed, and that causes the shoulder to move forward, and it won't chamber UNTIL you complete the sizing which will move the shoulder back again.

I don't know that this is the case in all, or many situations. It likely depends on the cartridge design, die dimensions, and the rifle chamber dimensions. In any case, your cases must not be getting sized enough. Adjust your die and see if it solves the problem.

Also, if you have a case that is VERY hard to size, (Surely, not a 270) and you are using a press that has a lot of FLEX, the case won't size well. There's a lot more about sizing than meets the eye.

In answer to your other questions, when I make 7mm Rem Mag cases into 7mm Wby, using a 7mm Wby sizing die, in order for the sized cases to chamber, I need to put a feeler gauge under the shell holder, to take out the slop.

Once they are sized enough to chamber they chamber hard, but after I fireform them they are fine, and chamber easily. They do have shorter necks, from the shorter 7 Rem Mag brass, but that creates no problems.

Smitty of the North

Thanks Smitty, I appreciate the input, particularly the part about your 7mm Wby cases, that sounds exactly what mine are doing. I'll load up a couple and shoot them and see what happens I think.