head space 223 rem. fired vs full length sized

[fguffey]

head space 223 rem. fired vs full length sized
« Reply #13 on: Today at 06:53 PM »Quote

"The problem was he pushed the shoulders back .013" from the fired dimension.

New brass length is irrelevant"

Alf,

No, measure first, then fire, after firing measure again, THEN after comparing the two measurements a bench rester/reloader should know how to adjust the die to compensate for the difference, again I am not a bench rester, I determine the length of the chamber first, others determine the difference between a minimum length size/new case and chamber after firing, the Hornady comparator should come with directions, then? maybe the directions are included.

F. Guffey

 

[fguffey]

He chambered a round, pulled the trigger and became a fire former, then with a Hornady case comparator he measured the case length from the head of the case to it’s shoulder, right there he should have applied the leaver policy, instead he full length sized the cases, and now someone is saying he should fire form the cases again, someone should explain to him what is happening to that case while it is doing all that traveling.

Someone should contact Hornady and suggest the instruction should read, measure first before firing, then again after firing, then if the person making the measurements does not understand the two measurements, call Hornady, I use transfers and standards, when making adjustments I verify the adjustment.

F. Guffey

 

[short range]

I'm going get rid of the brass that I set the headspace back 13 thousands because of the safety factor. it's not worth taking the chance. I'm going to barrow a few new brass and take a measurement. I know what the fire formed measurement is, so as long as I set the headspace back .002 to .003 from fire formed, I think I should be good to go. I don't think the new brass measurement comes into play, other then the fact that I will know what that measurement is. So my plan is to buy 500 once fired Lake City brass full length resize them to make sure they measure .002 to .003 less than my fire formed measurement. If you think I should back off more than .002 to .003 let me know. I think someone said they back off .005 for their AR.

 

[fguffey]

Backing off .005” (thousandths, 5/1000) is the difference between minimum length, new, factory, full length 30/06 case length and the perfect go-gage length chamber, the 223 would be less, but the 223 is fired in an auto feed type rifle.

And again, a new case should be minimum length from the head of the case to the shoulder, the bench rester/reloader should not assume the case is minimum length/full length sized, it is a bad habit to fire then measure, a good habit is to measure first then fire and then measure again, I believe in transfers and standards, I transfer the difference between the length of a minimum length case and a fired case to the press, die and shell holder by adjusting the die to or off the shell holder.

If you purchase 500 fired cases, measure the length of the case from the head of the case to it’s shoulder, then compare the length to your fired cases, setting the shoulder back on your newly acquired cases may not be necessary because the .013” (thousandths 13/1000) is excessive, it is not likely your new purchase will have case bodies that long.

Again, I have a 30/06 with .016 thousandths (16/1000) head space, it would be mindless of me to chamber a minimum length/full length case case in that rifle and pull the trigger, I form/size new/once fired 280 Remington cases to fit the chamber with .000” head space, I purchase cases that have been fired in trashy old chambers, finding a case that has been fired in a chamber that is that trashy will never happen, on the outside looking in someone would think the rifle should be repaired, the rifle came from the manufacturer with the long chamber.

F. Guffey

 

[RStewart]

I have a question- everyone is saying that the 13/1000ths would be excessive to refire-form, but isn't something like this done to create some wildcat cartridge brass? Isn't "blowing out a shoulder" doing that? I know original 6.5 Grendel brass was made from 6PPC brass. I am genuinely interested, not being belligerent.

 

[jamesh]

I have a question- everyone is saying that the 13/1000ths would be excessive to refire-form, but isn't something like this done to create some wildcat cartridge brass? Isn't "blowing out a shoulder" doing that? I know original 6.5 Grendel brass was made from 6PPC brass. I am genuinely interested, not being belligerent.

Go back and read Alf's posts. That is what he is suggesting.

James

 

[RStewart]

I have a question- everyone is saying that the 13/1000ths would be excessive to refire-form, but isn't something like this done to create some wildcat cartridge brass? Isn't "blowing out a shoulder" doing that? I know original 6.5 Grendel brass was made from 6PPC brass. I am genuinely interested, not being belligerent.

Go back and read Alf's posts. That is what he is suggesting.

James

I had heard about a false shoulder, but after posting I did some research and there were several articles on adding tension to the neck, jamming the bullet into the lands so the brass can't move and shooting as a hot a load as safe in the rifle to fire-form the brass. You opinion on this method?

 

[MQ1]

James,

When people are making wildcat cartridges and are forming their brass, there are a couple ways of doing, some being better than others...

Without going into a lot of detail, one of the best ways is to produce a false shoulder on the neck, so that the cartridge is supported with a slight crush fit when the bolt is closed on the usually stout fireform load. This supports the case for positive ignition, and allows the case to form consistently to the chamber.

This is typically done with new brass, not brass that has been shot a number of times...not that it is not possible, but you'll typically get longer life out of new, properly fire formed brass, without the concern of case separation that may come with brass fired and resized a bunch. I'll post a couple photos later to illustrate.

MQ1

 

[MQ1]

...yep...jamming works too. Dan Dowling chambered a .243AI for me, and one of the requirements for him to complete his chamber was a three pieces of the brass I was planning on fire forming. He chambered based on the dimensions of my brass, and instructed me to be certain to have my fire form loads have the bullet firmly into the lands. Again, this supports the cartridge for positive ignition and consistent expansion of the brass to the chamber dimensions.

A couple of ways to skin the cat. Then there is hydraulic forming and cream of wheat...

Mq1

 

[short range]

Rather than trashing your brass, I'd neck them up to 6mm, then back down to 22 in the die, now that you have it set at .002" bump. I'll form a secondary shoulder to headspace on, (like forming Dashers) and hold the brass and stop/slow down the potential problems at the web.

Can someone explain this to me in more detail ? Remember I am shooting this brass in an AR-15. I understand the necking up part of the process, but not the rest of the process. I will have to full length size these brass each time I shoot them in my AR.

 

[bigedp51]

Read the link below and click to enlarge the false shoulder photo.

http://www.6mmbr.com/6improvedform.html

Or if you have a good imagination just think of fguffey wearing a turtleneck and his head stuck in the chamber. :

 

[kelbro]

That sounds like a lot of shoulder bumping for a factory die set. What shellholder are you using?

A question that I haven't seen asked is, have you checked your headspace with a set of go/no-go gauges? Maybe your barrel is not set back far enough. Maybe someone swapped bolt/carriers.

 

[MQ1]

I'm attaching a picture of a once-fired and resized piece of 30-06 brass, a piece of the same brass that was annealed and necked down to 25-06, except that I sized only enough of the neck that I could chamber the brass with slight resistance on closing the bolt. If you look carefully at the case neck junction, you'll notice a little bulge (looks more like a line) that is the newly created shoulder where the case engages the chamber. The 3rd case is the fireformed 25-06 case.

MQ1

 

[fayettefatts]

That sounds like a lot of shoulder bumping for a factory die set.

I agree. My set up would cam over hard trying to get half that much set back.

 

[short range]

A question that I haven't seen asked is, have you checked your headspace with a set of go/no-go gauges? Maybe your barrel is not set back far enough. Maybe someone swapped bolt/carriers.
[/quote]

I do not have a set of go/no-go gauges. This is a brand new upper that I got from Stag, they said they tested it before it was sent to me.

 

[short range]

Read the link below and click to enlarge the false shoulder photo.

http://www.6mmbr.com/6improvedform.html

Or if you have a good imagination just think of fguffey wearing a turtleneck and his head stuck in the chamber. :

igedp51, Thanks for the info. Isn't this process much easier to do with a bolt action rifle ?

 

[bigedp51]

Yes this process much easier to do with a bolt action rifle, and my bolt action rifle doesn't throw my brass away either. :

BUT as stated earlier your dies seem to be pushing the shoulder back MORE than normal. Are you sure your dies and shell holder are OK and within specs?

And with three 5 Gal buckets of once fired .223 cases I would just chuck the short cases and start over.

 

[short range]

bigedp51, I am going to get rid of the brass that I screwed up, and start with once fired brass. I had my die screwed in too far is what caused the problem, I'm not sure how I or why I did that.
I didn't notice that it was set lower than normal until after I had resized all of my brass. In the past, I set the die according to Lee's directions, and I haven't had any problem. It's was a stupid mistake, and I was lucky that it didn't cause me or the rifle any harm. The way I caught the mistake was, I shot 10 rounds with that brass and noticed the primer were flattened, so I knew that I had excess pressure, so I checked the shoulder and found it was pushed back way to far. i have to admit that I haven't been checking headspace on the 5.56 brass because originally I checked it after setting up my die, and it was fine, so I wasn't checking it after that. I learned a lesson, from now on I will check my measurements on the first brass that I resize . I reset my die according to Lee's directions, and it's good to go now. I was just hoping that there was a way to save that brass.

 

[short range]

Thanks everyone for your input, I'm glad that I checked with all of you to answer my questions. I'm glad that I didn't try to fire form them with the shoulder pushed back so far. As you can see I'm still learning about reloading. I shouldn't take for granted that die settings are set correctly from the previous time that I used them. It only takes a minute to check. Thanks to this forum, I can get really great information.

 

[kelbro]

Setting your dies to match the chamber is a good idea. It still sounds like something is wrong somewhere in your sizing setup because I just tried and could not set a shoulder back that far with the press camming over.

It is possible that your die is short. Every 223 die set that I have ever seen needed the die to touch the shellholder for the brass to chamber easily.

Please check your brass after the second, third, or fourth firing for incipient casehead separation. Easily performed with a Sinclair ( ) paper clip.