30BR resiaing

adamsgt

Jerry Adams
This morning I fired most of the prepped brass I got with the used 30BR I bought. After putting my gear away and getting ready to process the fired brass I realized I din't know how this brass is to be treated. I got a Redding 30BR die with the gun that uses a bushing for neck sizing but I'm not sure about the rest. Do I bump the shoulder the way I do 6PPC or just full length size? 6BR web site didn't really address this issue.
 
I neck size only just to where the base of the bullet is. My brass has never been FL sized and I have been using it for about 3 years it has not gotten tight and I try to shoot 8 matches a year plus practice.
 
This morning I fired most of the prepped brass I got with the used 30BR I bought. After putting my gear away and getting ready to process the fired brass I realized I din't know how this brass is to be treated. I got a Redding 30BR die with the gun that uses a bushing for neck sizing but I'm not sure about the rest. Do I bump the shoulder the way I do 6PPC or just full length size? 6BR web site didn't really address this issue.

Think of the 30BR case as an enlarged 6PPC case. ALWAYS F/L size with your F/L Bushing Die [with your bushing of choice contained therein] that's been previously adjusted, to push the shoulder back .001" to .0015". It's all done with one downward pull of the press's handle. Always, Always, & Always F/L size. :)
 
some do...other don't.....why please.

so it's 2 completely different approaches to sizing brass. I have been on this forum for months now, reading all I can and I see this a lot. some do...... while other don't, but most posters don't tell us the WHY. would both posters like to tell us the why this time, please that is. I'm just trying to get a better understanding.

Bill Hodkinson
 
OK Bill

I don't know what to think either. I guess one measure of when to FL size is when you get the Click when the bolt opens fully. Then again, many people think that FL sizing overworks the brass and it won't last as long. Right now I've got 5 boxes of virgin Lapua gold box 6BR brass. At my age of 74 there'll probably be some left when I'm gone no matter which way I do it. I'm kind of leaning toward the FL sizing method as that's the way I do my 6PPC brass. I think I'll take some measurements on the fired brass then FL size a few and see what the difference is. The only question is whether I do it before or after my 3:00 PM senior nap. :D
 
so it's 2 completely different approaches to sizing brass. I have been on this forum for months now, reading all I can and I see this a lot. some do...... while other don't, but most posters don't tell us the WHY. would both posters like to tell us the why this time, please that is. I'm just trying to get a better understanding.

Bill Hodkinson

Here's a previous Q & A session that might help.

F/L Sizing is best!

Q: I am looking at a neck sizing die but would I be giving up anything by not going with a bushing die? Also what are the advantages of neck sizing besides not overworking the brass.

A: By not going to a bushing die you give up the option of fine tuning your load.

When you only neck size brass, you DO overwork it!

It's NOT a matter of frequency, It's a matter of the distance brass has to be worked/pushed back to its original dimension and the additional force required to do that, that defines Overworking.

When you full length size, regardless of chamber size, you're pushing the shoulder down about .001", pushing it inward about .0005" and pushing in the base/head area about .001", and squeezing down the neck a requisite distance, each time you pull the handle on the press. To do all of that, you need only one die.

When you neck size only, the body of your case is not touched and continues to expand a small amount each time it's fired, until such time, that you can no longer chamber it. To bring it back into the original designed dimension now requires an additional die [more money for the die manufacturers, now you own TWO], and a greater force to get it back to the designers specs [hence more force, over a greater distance = overworking]

By Full Length Sizing each and every time you reload will ensure: 1. The brass is worked very little, 2. You'll always be able to chamber your perfectly dimensioned round, and 3. You'll only need one die [preferably a bushing die].

Q. So a Harrell's would be what you mean right?

A. There are many fine custom die makers.

However, for $75 shipped, from Harrell's: http://harrellsprec.com/index.php?crn=207 , you not only get all the proper sizing dimensions built into the die, you also get a bushing cavity with the right amount of play to ensure that only about 70% of the neck is sized. The remaining 30%, that's not sized, ensures the neck [and the entire cartridge] is centered in the chamber. Again, all for a modest price!
 
Here is my take on resizing:

The best fitting case you will ever get is the one that was just fired in your chamber. Do the least resizing you can get away with, which if the case still chambers without resistance, means resizing just enough of the neck to hold the bullet. The remaining unsized part of the neck is the most important part of the case, because it fits tightly into the neck of the chamber, aligning the bullet. If you shoot mild loads, this is the only resizing you may ever have to do.

On the other hand, if you eventually get a click on bolt lift or resistance on bolt drop, then it is time to FL resize the minimum amount that allows easy chambering. It is advantageous to FL size the body separately from the neck so that you can maintain the unsized part of the neck for bullet alignment. A Redding body die, or any bushing die without the bushing installed, will do this for you. More accurately, you want to FL resize before you get a click or resistance, because forcing the bolt torques the rifle in the rests, which can upset the consistent dynamics of the rifle/rest system and throw off the next shot.

Cheers,
Keith

PS. I haven't tried this, but it should be possible to adjust a bushing FL die to partially size the neck while fully sizing the body. Then you could do the two operations, when both are needed, in one pull. (Oops, Abintx already does this.)
 
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abintx your post says: you not only get all the proper sizing dimensions built into the die, you also get a bushing cavity with the right amount of play to ensure that only about 70% of the neck is sized. The remaining 30%, that's not sized, ensures the neck [and the entire cartridge] is centered in the chamber.

I have a couple of Harrell dies and did not realize they adjusted the bushing cavity. I was doing that manually using an O-ring of appropriate size between the decapping stem and the die body of my Harrells die. I'd better revisit that setup.
 
"When you only neck size brass, you DO overwork it!

It's NOT a matter of frequency, It's a matter of the distance brass has to be worked/pushed back to its original dimension and the additional force required to do that, that defines Overworking.

When you full length size, regardless of chamber size, you're pushing the shoulder down about .001", pushing it inward about .0005" and pushing in the base/head area about .001", and squeezing down the neck a requisite distance, each time you pull the handle on the press. To do all of that, you need only one die.

When you neck size only, the body of your case is not touched and continues to expand a small amount each time it's fired, until such time, that you can no longer chamber it. To bring it back into the original designed dimension now requires an additional die [more money for the die manufacturers, now you own TWO], and a greater force to get it back to the designers specs [hence more force, over a greater distance = overworking]"




Ok explain this to me by only neck sizing it works the brass more? How? How is sizing only the neck more stressful to the case than full length sizing?
 
In my experience, one firing does not take brass to its maximum shoulder to head dimension, so when I am working with a new caliber/chamber, I neck size and fire one case a few times, with a stout load, monitoring the shoulder to head dimension, with my Stoney Point (now made by Hornady) "headspace gauge", until is seems to have reached its maximum. At that point, the bolt usually closes with more effort than I like. (Make sure your lugs are properly greased while you do this.) I set my die to bump brass back from that maximum. Of course the whole tight case procedure depends on being able to load where I shoot. If I am not able to do this, because I am not loading at the range, for once fired brass, this generally means that I will set the die to produce a head to shoulder dimension that is the same as it came out of the rifle after firing. (which generally gives a satisfactory bolt close)

Another thing that is worth mentioning is that when relatively small groups of brass are used a number of times, at some point, because of work hardening, the die will have to be reset to produced the desired amount of bump. Because of this, I keep close track of this dimension when starting a new cycle of sizing, and remove the die when I finish a loading session, so that I will not leave it set for older brass, when starting with new. In the past, when I have forgotten to reset for new brass, the shoulders of a few cases were set back .0035 instead of the desired .001 or slightly less.

To facilitate easy fine tuning of my die's setting, I use a Hornady lock ring above a Lee. Once the Lee is set where I want it, in the middle of its O ring's compression range, with the desired bump, I lower the Hornady into contact with it, tightening it to lock the Lee in place, by the spreading action that takes place when it is tightened. This setup makes small adjustments easy and stable, as well as slightly improving average concentricity of sized brass, because of the O ring. (Obviously this advantage is lost if the Lee ring is overtightened to the point that it goes metal to metal with the press.)
 
I bump cases no more than .0015, and usually .001 or a little less, with a die that does nothing to the shoulder diameter, and only sized the bases about .0005. Even so, as the firings, and FL sizings accumulate, I have to reset my FL die to keep the bump where I want it. That is hard data, gathered over many years of experience. As I mentioned above, a die setting that produces .001 bump on old, well used brass, has given .0035 on brass that has only been fired around three times. Evidently, exceeding the elastic limit of brass requires very little movement, or perhaps the fellows that came up with that bit of information had never worked with brass that was subjected to the same conditions as cartridge cases that are reloaded multiple times.
 
I bump cases no more than .0015, and usually .001 or a little less, with a die that does nothing to the shoulder diameter, and only sized the bases about .0005. Even so, as the firings, and FL sizings accumulate, I have to reset my FL die to keep the bump where I want it. That is hard data, gathered over many years of experience. As I mentioned above, a die setting that produces .001 bump on old, well used brass, has given .0035 on brass that has only been fired around three times. Evidently, exceeding the elastic limit of brass requires very little movement, or perhaps the fellows that came up with that bit of information had never worked with brass that was subjected to the same conditions as cartridge cases that are reloaded multiple times.

Boyd,
The Young's modulus of brass is E = 16000 ksi and the elastic limit of soft and hard brass are about Ey = 10 ksi and 33 ksi, respectively. Therefore, the strains required to exceed the elastic limit are Ey/E = 0.0625% and 0.206%, respectively. These strains quantify how much brass dimensions will recover elastically from any deformation large enough to exceed the elastic limit. For a 6PPC shoulder dimension of 1.22", these are 0.0008" and 0.0025". So to get the bumps you have observed, the estimated bumps set in your die are 0.0035 (final bump) + 0.0008 (elastic bump) = 0.0043" for soft brass and 0.001 + 0.0025 = 0.0035" for hard brass. Note that these numbers aren't exactly the same (they are off by 0.0008"), and they should be to match your observations. But they are pretty close for the roughness of the estimates. A little error in measurements and in estimating elastic limits could easily explain the difference.

Cheers,
Keith
 
he RIDES again! 30 posts and hes YELLING in the posts like STOOL and MIKE IN CO and forgets hes SUPPOSED to act like a NEW GUY
 
DO NOT BELIEVE EVERYTHING YOU READ IN WIKI.it is an unverified source of INFORMATION, not DATA.
there is plastic and elastic deformation, if the case is fired in the 50-62kpsi region there will be some plastic deformation.
i know of now load in a 30 br that is below the point of plastic deformation.
and then it begins to work harden.

Wiki might be wrong? Say it ain't true! :eek:

Actually, Wiki is fine in this case for our purposes. You find the same info in dozens of solid mechanics textbooks. But we are on the same page. Technically, there is no work hardening if the deformation is entirely elastic, but most deformations of shoulder length and neck diameter (the measurements with which we are most concerned) in BR cartridges are plastic. One exception is tight necks that were popular years ago. If you limit the deformation to something in the range of 0.0005", then its all elastic.
 
A little postscript on the brass

Today the mailman delivered a Wilson 30BR case gauge. I bought it to use with the Accugauge I use to check 6PPC shoulder setback. Anyway, I decided to drop a couple of the 30BR cases into the gauge and discovered that some wouldn't go in fully. I had only neck sized the brass so I decided to check them all in the gauge to see what was up. 29 pcs dropped right in, 19 were high in the gauge and 4 were way high. All the brass was primed so I removed the firing pin from the bolt and ran them through the chamber. The bolt handle dropped freely on the first 29 and on the 19 that were high. The remaining four required some force to close the bolt. I think I'll fire then as they are now and them full length size after that.
 
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You cant trust those case gauges on a custom chamber. Theres a million different 30br chambers and no standard.
 
You cant trust those case gauges on a custom chamber. Theres a million different 30br chambers and no standard.

Now you tell me that. Cmon Dusty, a million, really? Crap!

OK, nuff of that. I bought the case gauge to use with the Accugauge when I'm setting my sizing die to bump the shoulder. I use it to measure the case before and after sizing so I'm just looking for the difference. This particular case gauge from Wilson actually fits 30BR Rev 634,989.
 
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