when is 308 brass not working when converting to 7mm-08?

[crustyrusty]

I have 500 brass cases of multiple manufacturers , Barnes , Hornady, FC, Lake City ......I have tried all of these manufacturers and re-sized the cases into 7mm-08 brass using RCBS dies(new) and it doesn't matter the manufacturer they wont function in my brand new savage axis rifle so I bought once fired 7mm-08 brass and it fitted perfectly after sizing. OK so I tried neck turning, it helped but the bolt face tension was so strong that it marred the face of the 308 case face. ok so I have Redding competition shell holder kit and eventually went to .010 taller and still bolt turn pressure was too high it scarred the brass face of the cartridge. Well I got a real good deal on .243 Win brass, and went back to a standard shell holder and after re-sizing the new brass fit just perfect,,,,....
ok so i found some 260 rem brass bought 25 cases and and did the same thing to them as I did with the .243 Win brass
and they fit perfectly as well....... ok so 243 Win, 260 Rem brass work just peachy keen but the 308 brass is unusable.. any Ideas as to why 308 brass doesn't work? I would like to use that stuff up if I could.

 

[Murray Brook]

I've use 308 cases in my 7/08 with no problem. One pass through the resizing die and good to go. Neck is a little short is the only thing. Is your die turned down enough to bump the shoulder back enough for easy chambering. By the way try the .002 Redding shell holder, as it will give you more bump than the .010 one.

 

[RegionRat]

The Redding incremental shell holders are not what you try when you are suffering with brass that appears to be too tight to begin with since they are used for making shoulders longer not shorter.

1) Have you been able to get a shoulder datum length gage on these?

2) How about a diameter reading on them at about 0.200" above the base?

3) I assume the neck length and diameters have been the focus so they should have been checked up front?

One of the first two accounts for about the vast majority of the instances where cases are too tight. When making 7-08 out of 308, make sure you start with 308 that otherwise gages well in a gage or chamber before you convert it otherwise don't expect that neck reduction operation to go smoothly.

 

[gunsandgunsmithing]

I have 500 brass cases of multiple manufacturers , Barnes , Hornady, FC, Lake City ......I have tried all of these manufacturers and re-sized the cases into 7mm-08 brass using RCBS dies(new) and it doesn't matter the manufacturer they wont function in my brand new savage axis rifle so I bought once fired 7mm-08 brass and it fitted perfectly after sizing. OK so I tried neck turning, it helped but the bolt face tension was so strong that it marred the face of the 308 case face. ok so I have Redding competition shell holder kit and eventually went to .010 taller and still bolt turn pressure was too high it scarred the brass face of the cartridge. Well I got a real good deal on .243 Win brass, and went back to a standard shell holder and after re-sizing the new brass fit just perfect,,,,....
ok so i found some 260 rem brass bought 25 cases and and did the same thing to them as I did with the .243 Win brass
and they fit perfectly as well....... ok so 243 Win, 260 Rem brass work just peachy keen but the 308 brass is unusable.. any Ideas as to why 308 brass doesn't work? I would like to use that stuff up if I could.

Are they bushing dies, by chance? Nevermind, I just saw where you still have the problem after turning necks. I was gonna say that the neck may not be sizing all the wat to the neck/shoulder junction but turning should fix that.

 

[crustyrusty]

well lets see..... I started out with the standard number 1 shell holder or number 2 I just don't remember the correct numbering for the shell holder. I set the die to contact the shell holder with a mild cam over on the arm of the press. when I reload 308 rounds for my boss this brass is smooth as silk in his Winchester 100. when I set it up for the 7mm-08 die I set it up exactly as explained. using the standard shell holder, the re-formed brass acts just like a no-go gauge..you cannot close the bolt at all. if I use redding comp shell holders and move back the shoulder some I can start to turn the bolt in increments untill I get to the last shell holder marked .010 where I can get full bolt turn but with goodly pressure. I was under the impression that the Redding shell holders were to move the shoulder back in essence making the case shorter. I really am in for a loss as to why I cant seem to make these work.

 

[crustyrusty]

The Redding incremental shell holders are not what you try when you are suffering with brass that appears to be too tight to begin with since they are used for making shoulders longer not shorter.

1) Have you been able to get a shoulder datum length gage on these?

2) How about a diameter reading on them at about 0.200" above the base?

3) I assume the neck length and diameters have been the focus so they should have been checked up front?

One of the first two accounts for about the vast majority of the instances where cases are too tight. When making 7-08 out of 308, make sure you start with 308 that otherwise gages well in a gage or chamber before you convert it otherwise don't expect that neck reduction operation to go smoothly.

the diameter at .200 above the base is the same as at the base itself .468, 1.553,to the shoulder, 1.75 to the base of the neck where the neck clearly stops, and 2.00 oal.
as for a shoulder datum length gauge I will gladly show my ignorance and say "whats that?"

 

[Sandstorm]

The * 10 shell holder moves the shoulder bump the least amount...and
the # 2 the most.

 

[crustyrusty]

the diameter at .200 above the base is the same as at the base itself .468, 1.553,to the shoulder, 1.75 to the base of the neck where the neck clearly stops, and 2.00 oal.
as for a shoulder datum length gauge I will gladly show my ignorance and say "whats that?"

neck diameter is .3105 after necking down and is .238 long
so if I am trying to convert brass that has seen high PSI loads don't expect much?
I noticed on several pieces that I looked at that you could see ejector marks on the face of the brass that I chose too convert

 

[Sandstorm]

You really need once fired brass for optimum results.

 

[RegionRat]

Redding incremental shell holders don’t help size more, they help size less,

If a regular shell holder can be assumed to give you at or below SAAMi minimum, then going from incremental holder +2, to +4, to +6 etc, will make that brass longer by +0.002, +0.004, +0.006” etc. Not shorter. So, anything in that kit is designed to work brass down less, not more.

If anything, we need to see if it is the shoulder length headspace that is the issue, or the body diameter at some point.

Is the root of the neck at the shoulder junction fully formed? Try flipping the bushing with the sharper radius down and see if that radius makes any difference, but use a regular shell holder with complete closure on the die or good cam over.

Also, by chance have you got any factory 7-08 that fits well for a comparison?

 

[crustyrusty]

Redding incremental shell holders don’t help size more, they help size less,

If a regular shell holder can be assumed to give you at or below SAAMi minimum, then going from incremental holder +2, to +4, to +6 etc, will make that brass longer by +0.002, +0.004, +0.006” etc. Not shorter. So, anything in that kit is designed to work brass down less, not more.

If anything, we need to see if it is the shoulder length headspace that is the issue, or the body diameter at some point.

Is the root of the neck at the shoulder junction fully formed? Try flipping the bushing with the sharper radius down and see if that radius makes any difference, but use a regular shell holder with complete closure on the die or good cam over.

Also, by chance have you got any factory 7-08 that fits well for a comparison?

Yeah I just got off you tube and this guy explained these Redding shell holders real well now I know where I went wrong(I think) Yes I have good 7mm-08 that fits well as does the converted 243 win and 260 rem brass,, and thanks for your example as well it was very easy to see how it works and I have been thinking in exactly the opposite!

 

[crustyrusty]

OK after taking in everybodys ideas and cues I went downstairs to my reloading bench and took everything completely apart and cleaned everything very well. Then I re-installed my 7mm-08 die to my Redding Boss press ,, set the depth to interfere with the arm to a mild over cam on the arm using the standard shell holder
I re-ran all 100 pieces of 308 brass that wont work, and took my time running them thru, holding the arm at full cam over for a full 5 count then lowering it down. for the first 5 or so pieces I test fit it in my rifle and low and behold fit was perfect so whatever I was doing wrong I am now doing right, Thanks again guys for all of your valuable insight and advice! Rusty

 

[snert]

Yeah I just got off you tube and this guy explained these Redding shell holders real well now I know where I went wrong(I think) Yes I have good 7mm-08 that fits well as does the converted 243 win and 260 rem brass,, and thanks for your example as well it was very easy to see how it works and I have been thinking in exactly the opposite!

Don't feel bad....even the tech (me) at Redding got confused now and then!!!! And every time I pull out my COMP shell holders I have to remind myself to "think opposite!"

 

[ronemus]

Are you using the same brand of shell holder as the sizing die? The is no standard for shell holders, so you get unpredictable results when you mix and match.

Has the rifle been checked with a headspace gage? If not, get it checked - you may have a tight chamber. Factory ammo is usually well under the dimensions for a SAAMI minimum chamber, so the chamber may still be tight even though it accepts factory ammo. Reloading dies usually don't size much below SAAMI max for the brass.

You don't say what neck thickness you are turning to, but if it's thicker than 0.013" you may not fit in the chamber.

 

[RegionRat]

OK after taking in everybodys ideas and cues I went downstairs to my reloading bench and took everything completely apart and cleaned everything very well. Then I re-installed my 7mm-08 die to my Redding Boss press ,, set the depth to interfere with the arm to a mild over cam on the arm using the standard shell holder
I re-ran all 100 pieces of 308 brass that wont work, and took my time running them thru, holding the arm at full cam over for a full 5 count then lowering it down. for the first 5 or so pieces I test fit it in my rifle and low and behold fit was perfect so whatever I was doing wrong I am now doing right, Thanks again guys for all of your valuable insight and advice! Rusty

Glad that worked out. I think highly of the 7-08. It makes an excellent silhouette caliber.

We should still get you to the point where you have good headspace gages and can independently watch that sizing process and control it.

 

[crustyrusty]

Glad that worked out. I think highly of the 7-08. It makes an excellent silhouette caliber.

We should still get you to the point where you have good headspace gages and can independently watch that sizing process and control it.

Thanks I see headspace gauges on my horizon as I dont own a single one and this adventure has just taught me a valuable lesson.

 

[crustyrusty]

Are you using the same brand of shell holder as the sizing die? The is no standard for shell holders, so you get unpredictable results when you mix and match.

Has the rifle been checked with a headspace gage? If not, get it checked - you may have a tight chamber. Factory ammo is usually well under the dimensions for a SAAMI minimum chamber, so the chamber may still be tight even though it accepts factory ammo. Reloading dies usually don't size much below SAAMI max for the brass.

You don't say what neck thickness you are turning to, but if it's thicker than 0.013" you may not fit in the chamber.

You know what? I thought the exact same thing! was the rifles headspace to tight? I did order go-gauges from pacific tool just to have on hand(maybe a reamer too to try my hand a silhouette shooting this summer)
I turned ten cases to .308 diam I didn't measure the wall thickness, but fresh 308 case swedged to 7mm goes to a new neck diameter of .31055.

 

[RegionRat]

https://www.midwayusa.com/product/1012939524

There are many ways to watch your case shoulder datum for headspace, so I figured you might want to see a few ideas or leave them laying around to see if Santa picks them up for you... Many places to shop for these types of tools, I just pushed an easy button and used Midway as an example.

https://www.midwayusa.com/product/1012743827?pid=479704

https://www.midwayusa.com/product/1012753414?pid=277695

https://www.midwayusa.com/product/1012747079?pid=570611

https://www.midwayusa.com/product/101273351?pid=231904

In addition to shoulder length, you are going to end up with bullet comparator tools too, so you may as well start collecting those too....

Merry Christmas.

 

[crustyrusty]

https://www.midwayusa.com/product/1012939524

There are many ways to watch your case shoulder datum for headspace, so I figured you might want to see a few ideas or leave them laying around to see if Santa picks them up for you... Many places to shop for these types of tools, I just pushed an easy button and used Midway as an example.

https://www.midwayusa.com/product/1012743827?pid=479704

https://www.midwayusa.com/product/1012753414?pid=277695

https://www.midwayusa.com/product/1012747079?pid=570611

https://www.midwayusa.com/product/101273351?pid=231904

In addition to shoulder length, you are going to end up with bullet comparator tools too, so you may as well start collecting those too....

Merry Christmas.

OK I just ordered them all up !!! thanks for the christmas list!

 

[ronemus]

fresh 308 case swedged to 7mm goes to a new neck diameter of .31055

You might get into some trouble there because a SAAMI chamber neck is 0.314" and your necks will be larger after seating a bullet; you're in a place where a kaboom could happen. There was a time when benchrest shooters would run clearances as small as 0.002" loaded diameter (monitored VERY closely), but 0.004" or more would be typical now - the benefit wasn't there for really tight clearances. If your loaded neck diameter is at or above 0.314", that would explain your problems. It doesn't seem as though you've fired any of these reloads yet, and that's a very good thing because there's a good chance that you would have injured yourself or damaged the rifle.