Excessive Headspace and Sizing Cases

[1hole]

yes, just back off the full length die to achieve neck sizing only. It doesn't take much backing-off, I usually back off 1/4 of a turn.

A quarter turn to a standard die produces some 18 thousants of change; that's a huge difference when making bottle neck case headspace adjustments!

There is no reason to adjust bottle neck shoulder set back for one or two thousants, fired case's lengths spring back that much same as does case diameter.

IF we want max case life as well as easy chambering simply adjust the FL sizer to duplicate the fired shoulder length, there's no need for sizing it back any further.

[kentfielddude]

I took the bore video before the request so its not the best video. I currently don't have access to the rifle right not.

[huntinlever]

I would have to disagree with you about the mild loads. I have found that cases will often not fireform to the chamber fully without a full power load and even then it sometimes takes 2 or 3 firings. This isn't a big issue unless you are measuring shoulder set back. Once you go down that road if your cases are already a a few thousands from being fully formed and then you set them back .002" now you just compounded the very problem you are trying to fix.

Sorry for the hijack, but after dialing in the shoulder set-back on my 338, I want to do the same for my son's 30-06 and 30-30. Is the notion of needing 2-3 firings for a complete fire-forming necessary across all the calibers (i.e., does a 338 mag fill out pretty much on 1st firing, but a moderate 30-30 may need several)?

[huntinlever]

A quarter turn to a standard die produces some 18 thousants of change; that's a huge difference when making bottle neck case headspace adjustments!

There is no reason to adjust bottle neck shoulder set back for one or two thousants, fired case's lengths spring back that much same as does case diameter.

IF we want max case life as well as easy chambering simply adjust the FL sizer to duplicate the fired shoulder length, there's no need for sizing it back any further.

-so the "standard" 0.002" set back is basically useless, given spring-back? And a bit confused on your last paragraph - isn't a fired shoulder length and unsized (fired) case going to have the same shoulder length? What are you actually sizing then? Neck diameter? Thanks for the explanation.

[huntinlever]

The basic instructions that the die makers recommend are just that basic and a starting point that should work in all SAAMI spec chambers. That doesn't mean they are the optimal method of adjusting your dies. For the most part I have given up on neck sizing only. I do control the shoulder bump to .001" to .002" for bolt guns and .002" for 003" semi-autos, pumps and lever guns.

When you have a chamber with excessive headspace the best methods are to neck up and form a false shoulder or jam the bullet into the lands if you can. That will eliminate the excessive case stretch from the first fireforming.

Once you have a case that is fully formed to the long chamber you need to set your die for the amount of shoulder bump you want. The Hornady Lock-N-Load® Headspace Comparator or the RCBS Precision Case Mic work well for this.

You set the should bump by slowing adjusting the die until you get the bump you want.

No need to have the barrel setback using these methods. You basically are loading for a very mild form of wildcat is the chamber is outside SAAMI specs.

Good overview of the process here

http://www.floridareloading.com/inde...tleneck-cases/

Just my noob's experience point. I have the precision mic for the 338, but wasn't a fan of the bullet seating depth setup. I got the Hornady, both for headspace and bullet depth, across my 30-30, 30-06 and 338 WM. Like it much better, and it doesn't cost much for the separate calibers.

[M-Tecs]

-so the "standard" 0.002" set back is basically useless, given spring-back? And a bit confused on your last paragraph - isn't a fired shoulder length and unsized (fired) case going to have the same shoulder length? What are you actually sizing then? Neck diameter? Thanks for the explanation.

The .002" setback is after the spring back. That's where annealing is helpful. It makes the spring back more consistent. I get as much as .003" spring back variations on brass that is not annealed. With annealed holding less than a 001" is normal. If using a expander ball a carbide button with lube improves consistency.

[huntinlever]

The .002" setback is after the spring back. That's where annealing is helpful. It makes the spring back more consistent. I get as much as .003" spring back variations on brass that is not annealed. With annealed holding less than a 001" is normal. If using a expander ball a carbide button with lube improves consistency.

So, should I fire-form the case 2-3X, annealing each time, check with the gauge, then set back accordingly?

[M-Tecs]

Just my noob's experience point. I have the precision mic for the 338, but wasn't a fan of the bullet seating depth setup. I got the Hornady, both for headspace and bullet depth, across my 30-30, 30-06 and 338 WM. Like it much better, and it doesn't cost much for the separate calibers.

I have both. The RCBS is direct reading meaning it gives you an actual direct measurement. The Hornady is a comparator and only gives you an indirect measurement unless used with a standard like a headspace gauge. When working with multiple chambers I much prefer direct measurements from the RCBS.

[huntinlever]

I have both. The RCBS is direct reading meaning it gives you an actual direct measurement. The Hornady is a comparator and only gives you an indirect measurement unless used with a standard like a headspace gauge. When working with multiple chambers I much prefer direct measurements from the RCBS.

OK, I get it. Thanks.

[M-Tecs]

So, should I fire-form the case 2-3X, annealing each time, check with the gauge, then set back accordingly?

Question like this are why I prefer the RCBS. The zero setting is the actual minimum headspace. If you measure most unfired factory brass it will be .002" to .005" less than minimum. The exceptions are belted cases. Since they HS off the belt the shoulders can be way less. I've had factory belted that's .030" short of the shoulder datum.

For normal hunting applications bumping the shoulder .003" will give great accuracy and the brass will fail from loose primer pockets or neck splits long before head separation becomes an issue.

I have actual headspace gauges for most of the calibers I have. For the 223, 308 and 30/06 I have them in .001" steps so I know actual chamber specs. On the ones that I only have the go gauge I use shims to get the chamber HS specs.

[huntinlever]

Question like this are why I prefer the RCBS. The zero setting is the actual minimum headspace. If you measure most unfired factory brass it will be .002" to .005" less than minimum. The exceptions are belted cases. Since they HS off the belt the shoulders can be way less. I've had factory belted that's .030" short of the shoulder datum.

For normal hunting applications bumping the shoulder .003" will give great accuracy and the brass will fail from loose primer pockets or neck splits long before head separation becomes an issue.

I have actual headspace gauges for most of the calibers I have. For the 223, 308 and 30/06 I have them in .001" steps so I know actual chamber specs. On the ones that I only have the go gauge I use shims to get the chamber HS specs.

I think I should re-do the setback to 0.003, since I'm just looking to prolong life, and only needing hunting applications. I can see the inherent variables might make my current 0.002" iffy, anyway.

One issue that comes to mind for me, with the RCBS, is coming to a consistency "stop" torque or pressure. I was able to (blind) replicate several cases, so think I'm getting it. But I can also see how even slight variances in how much pressure I'm applying can throw things off. I've only used the Hornady OAL gauge for bullet seating, but the hard stop is kind of appealing to me. On the other hand, I can see how that has its own issues - i.e., as with any caliper reading, making sure the case is resting true against the caliper blade and not dialing in with any force there, either.

At the end of the day, I really just want decent life for hunting. While I have a lot of confidence in the headspace measurements from the RCBS, the coin in getting one for each new caliber is a bit of a deterrent for me. You probably get what you pay for. I hope going the Hornady bushings way is doable.

[1hole]

I have a m1917 that eats a field gauge. I'm kind of scared to shoot it to form the brass. If I seat a cast bullet so it jams into the rifling is it safe or is there still a concern with saftey?

Without going into a lengthy epistle about internal ballistics and the low yield strength strength of lead bullets I'll just say "no".

[1hole]

[quote[The .002" setback is after the spring back. That's where annealing is helpful. It makes the spring back more consistent.

Maybe, but read what I posted in the context of the discussion. I don't believe any cases are so well made nor is any annealing method so consistent that "holding" shoulder set back within a thou or less is possible.

Even if it were physically possible to do so with such precision, reasonably consistent shoulder set back is obviously a factor but high quality ammo doesn't depend on one or two thousants of shoulder set back. Good cases need much more care than chasing such trivial measurements as that.

I get as much as .003" spring back variations on brass that is not annealed.

Problem with striving for that, for most of us anyway, is annealing case necks that consistent without overheating them to dead soft with no spring back IS a real problem.

With annealed holding less than a 001" is normal.

So, "holding" shoulder set back to "less than a thou is normal"? I doubt that. In fact I doubt any reloader's tools and ability to even measure shoulder set back with such accuracy.

And, yeah, I have done a bit of case neck annealing and measuring for a very long time. Your photo looks like a precisely over heated neck to me.

[huntinlever]

Maybe. But quality ammo doesn't depend on one or two thousants of shoulder set back, good cases need much more care than that.



Problem with striving for that, for most of us anyway, is amature annealing case necks that consistent without overheating them to dead soft with NO spring back is a real problem.



I don't see how proper neck annealing would make shoulder sizing/set back that predictable. ???



Yes, some carbide expander balls can, or may, work better than most steel expander balls but I've found that - on average - nothing produces straighter necks on common cases as well as Lee's unique Collet Neck Sizers. Use that neck die for best - on average - straight case necks. Use it in combination with any body die to set shoulders back as you wish.

I've only seen the term, so know even less about them than anything else. Researching, but are the collet dies used in tandem with a full-length sizing die?

[M-Tecs]

I've only seen the term, so know even less about them than anything else. Researching, but are the collet dies used in tandem with a full-length sizing die?

They are neck sizing dies only. Using a full-length die would defeat the purpose.

You can use Body Dies that are designed to full length resize the case body, bump the shoulder position for proper chambering, but not size the neck at all. I used Redding S Die's without the bushing installed when I used them with the lee.

The Lee worked great when new. The issue I had was after 3k to 6k even using the best lubricants on the camming surface they would be less consistent. After 3 or 4 I gave up on them. I mostly use Redding S dies. For competition ammunition I use the S die without an expander button since all the necks are the same thickness. For hunting and prairie dog ammo I still use the Redding S die but with a carbide expander button using a neck bushing based on the thinnest necks.

https://bulletin.accurateshooter.com...ee-collet-die/

https://bulletin.accurateshooter.com...shoulder-bump/

[M-Tecs]

Comments in blue.

Maybe. But quality ammo doesn't depend on one or two thousants of shoulder set back, good cases need much more care than that.

No one stated shoulder set back was the only component of quality ammo.

Problem with striving for that, for most of us anyway, is amature annealing case necks that consistent without overheating them to dead soft with NO spring back is a real problem.

Have you ever annealed a case? If you didn't get the results you wanted did you try to figure out why you failed when others succeed?

I don't see how proper neck annealing would make shoulder sizing/set back that predictable. ???

You are aware that when annealing the shoulder gets annealed also? I suggest looking at Lapua as a proper example since they don't polish after annealing. See below.

What methods are you using to measure shoulder set back? Myself and others have no problem holding a .001" should set back consistancy. It does take a learning curve that starts with the ability to accurately measure results. Without that it's not going to happen.


Yes, some carbide expander balls can, or may, work better than most steel expander balls but I've found that - on average - nothing produces straighter necks on common cases as well as Lee's unique Collet Neck Sizers. Use that neck die for best - on average - straight case necks. Use it in combination with any body die to set shoulders back as you wish.

[SoonerEd]

... Starting with new or once fired brass from a rifle with proper headspace neck size only and seat your cast bullets to engage the rifling when the bolt is closed. A mild load is better as it will not seize to the chamber walls like a full power load and let the case move back against the bolt face. When reloading these cases only neck size and try the cases in the chamber. If they chamber fine load them, if they are hard to close the bolt on size only enough to allow easy chambering. The cases are now fireformed to match your chambers headspace.

/\ This

[1hole]

/\ This

Ed, minus the normal fired case spring back in all dimensions, both you and Rich are absolutely correct. But ... as you allude, that's not all we are trying to achieve when we size for our very best average (practical) shoulder-to-head length!

Whatever action type we may be using we want the reloaded ammo to be accurate and chamber easily! We usually accomplish that by setting the shoulders of bottle neck cases back just a little bit from the fired length. Experience has shown that about .002" of setback from the fired shoulder length is usually enough for slick chambering and it causes no meaningful reduction of accuracy or case life.

[M-Tecs]

And, yeah, I have done a bit of case neck annealing and measuring for a very long time. Your photo looks like a precisely over heated neck to me.

That would explain why you hare having issues.

The pic you claim is overheated is from Lapua's web site of a new 30/06 case. https://www.lapua.com/product/30-06-...-case-4ph7068/

Here a bunch more Lapua overheated .

https://www.lapua.com/products/cartridge-cases/

Same for Lake City GI brass.

https://www.308ammo.com/30-06-M72-30...p/m7212251.htm
https://www.goldcountryammo.com/prod...n-fmj-bullets/

Same for Hornady
https://www.surplusammo.com/products...20-rounds.html

Maybe you should contact Lapua, LC and Hornady and explain how they are overheating their cases??????

The Lapua, Hornady & LC pics represent what the case should look like after annealing. Using Tempilaq is also a good way to learn what to look for also.

So, "holding" shoulder set back to "less than a thou is normal"? I doubt that. In fact I doubt any reloader's tools and ability to even measure shoulder set back with such accuracy.

[/B]

Once again you are misreading/misunderstanding my post. Never stated holding the shoulder bump to .001" less. I did state holding consistency of a .001" or less with properly annealed cases is very doable.

The RCBS case mics and the Hornady case comparator are both capable of .001" resolution with the proper feel. That applies to most precisions measuring instruments like micrometer and dial calipers. If you force mic's you can get considerable errors.

Both my RCBS Precision Mic's and Stoney Point/Hornady case comparator are calibrated off of actual headspace gauges. The headspace gauges are verified using 100 to 1 optical comparator.

Same for my home-built version loosely based off of Larry Willis's patented Digital Headspace Gauge https://www.larrywillis.com/

This one works well for the folks that can't get a feel for using mics or calipers.

Again how are you measuring your cases?

[M-Tecs]

So, should I fire-form the case 2-3X, annealing each time, check with the gauge, then set back accordingly?

For what you are doing and looking for using a middle of the road or a full pressure load with a case that is lightly oiled will get you the info you need. Stay away for mild loads for establishing shoulder bump. If the load doesn't have enough pressure to overcome the primer strike and primer pushout the brass can actually get shorter at the shoulder datum.