Neck Tension Conundrum - Double Check Me...

[j-dubya]

In an effort to get some use out of a bunch of stainless tumbled brass I mothballed years ago due to giving me fits with sizing and fliers on target, I brought the bushing die and mandrel back into my 308 loading. 308 shooting the past few years has been all gas gun, so I’ve stuck with my known load and the Forster FL die for sizing and speed of process. Gives around .003-.004 runout when not fucking with stainless tumbled brass. Bringing the bushing die and mandrel back into the equation, runout comes down to <.002 with about 50% being .001 or under. I thought I’d make some control rounds with this process on my non-stainless tumbled brass for comparison so I could see if the stainless brass was still giving me fits.

When I AMP anneal the brass and run it through the bushing/mandrel process, my solid and constant SD/ES’s from the Forster FL rounds climb significantly, as well as erratic groups. Some are still awesome, others not so much. Regardless, numbers have gone to shit. Not the consistency of the Forster loads. HOWEVER, by dumb luck I had some rounds get loaded that I forgot to run through the AMP, and when shooting those, the velocity averages are stable and back in line with the known, good Forster load, and ES/SD’s came down even more along with even better results on target.

That’s what I’m trying to duplicate here: whatever the level of work hardening the brass is at at that point (around the same as the Forster FL die). So the current bushing I’m using in the Redding die is a .336, which sizes the Federal brass down to ~.3335, then the .002 mandrel to bring it back for bullet seating. Annealed brass loads go to shit with this process, but once-fired brass after last annealing shoots the best and improves over my Forster loads. Forster die sizes down to .321 without expansion. I tested that with the mandrel instead of the Forster expander ball thinking that would be the obvious quick-fix...and groups and numbers are still shit. I’m stumped there, but would rather eliminate all the extra sizing of that anyways.

Sorry for the novel, but I wanted to give context to what I’m fighting and what I’m up against. Comparing the freshly annealed brass to the non-annealed throughout the sizing process, the annealed brass necks are .001 larger than the non annealed during each stage from obvious spring back. So I have ordered bushings in .002 increments from .334 down to .328 and plan to test loaded rounds in order to find the sweet spot and duplicate the results on target and the numbers of the non-annealed brass.

Am I right in my thinking here or am I going the wrong direction? Any help and insight is greatly appreciated!

 

[straightshooter1]

Are you annealing before or after you clean your brass?

As I recall, I had similar issue when I annealed my .308 brass after cleaning and I got better results if I annealed before cleaning. The only explanation I could find is that when annealing after cleaning that annealing sees to char whatever may be still clinging to the interior of the neck causing more release tension. So, I anneal before I clean every time and it works pretty well. Or . . . I guess one can lube the neck or bullet before seating so you don't have that increase tension issue.

 

[Precision Underground]

My guess is you are dealing with friction inside the necks, not tension. If the numbers go back to normal after firing once I’d just about guarantee that’s what you are dealing woth.

 

[Steel head]

My guess is you are dealing with friction inside the necks, not tension. If the numbers go back to normal after firing once I’d just about guarantee that’s what you are dealing woth.

this.

 

[j-dubya]

Doing a fairly quick tumble, annealing, then sizing.

As to the friction - it’s the same exact procedure each time for what’s going on inside the neck... only difference is annealing. Prior to the mandrel, the necks get a couple of rolls in Imperial graphite with the ceramic balls. Brass processing and loading procedure is the exact same each time, with the exception of annealing. Remember: the load I’m trying to duplicate is from the annealed brass going through the Forster die and expander ball... Forster die takes the brass all the way down to .321 and then the expander pulling back through to .336. Bushing die with mandrel only sizes down to .333 and then back up to .335. Doing that process with the annealed brass makes things go to shit. To me it’s a work-hardening issue...the good load is based on a lot of work hardening from the annealed state, and the new process doesn’t give it that much work. But doing the new process after a sizing process, seating, firing, and another sizing and seat, the load is back to normal. To me, that’s work hardening. What’s going on inside the neck is identical.

ETA- to me it’s a grip issue due to the difference of annealed to non annealed. So friction coming from that train of thought makes sense. I just need to duplicate that “friction”.

 

[Precision Underground]

Doing a fairly quick tumble, annealing, then sizing.

As to the friction - it’s the same exact procedure each time for what’s going on inside the neck... only difference is annealing. Prior to the mandrel, the necks get a couple of rolls in Imperial graphite with the ceramic balls. Brass processing and loading procedure is the exact same each time, with the exception of annealing. Remember: the load I’m trying to duplicate is from the annealed brass going through the Forster die and expander ball... Forster die takes the brass all the way down to .321 and then the expander pulling back through to .336. Bushing die with mandrel only sizes down to .333 and then back up to .335. Doing that process with the annealed brass makes things go to shit. To me it’s a work-hardening issue...the good load is based on a lot of work hardening from the annealed state, and the new process doesn’t give it that much work. But doing the new process after a sizing process, seating, firing, and another sizing and seat, the load is back to normal. To me, that’s work hardening. What’s going on inside the neck is identical.

ETA- to me it’s a grip issue due to the difference of annealed to non annealed. So friction coming from that train of thought makes sense. I just need to duplicate that “friction”.

Is the issue with the stainless brass or the brass that was shooting good? I am having a hard time following what exactly you are doing/trying to do. Are you trying to make the stainless brass shoot or are you trying to just use a different die on the other brass?

In my experience annealing “dries” the necks out and makes for more friction. Not sure why it does this but I have noticed it, especially on extra clean brass. And I can’t imagine a load going to hell because it needs more work hardening. This is why I’m thinking friction. After you fire the case the neck is coated with carbon again and all goes back to normal.

 

[j-dubya]

No, the stainless brass isn’t being used yet. It’s just what sent me down this road to changing my current procedure.

Reason I believe work hardening is at play here is due to the known, existing good load is based on a piece of annealed brass getting worked extra hard through the Forster FL die. The new process has a minimized working effect with the bushing eliminating the additional .012 of compression prior to being expanded back up to .336. No graphite is applied to the neck during the Forster sizing, just whatever carbon is there (this is why I stopped with the stainless tumbling years ago). Graphite gets added to the new process for the mandrel step. I have always used graphite for bullet seating,

My first thought to lessen the variables was run the annealed brass through the Forster die without the expander ball, and instead use the mandrel. But the rifle and the target didn’t like that. I’m still not sure what that’s about. Only other thing I could try is a .001 mandrel since I have it too.

 

[Precision Underground]

No, the stainless brass isn’t being used yet. It’s just what sent me down this road to changing my current procedure.

Reason I believe work hardening is at play here is due to the known, existing good load is based on a piece of annealed brass getting worked extra hard through the Forster FL die. The new process has a minimized working effect with the bushing eliminating the additional .012 of compression prior to being expanded back up to .336. No graphite is applied to the neck during the Forster sizing, just whatever carbon is there (this is why I stopped with the stainless tumbling years ago). Graphite gets added to the new process for the mandrel step. I have always used graphite for bullet seating,

My first thought to lessen the variables was run the annealed brass through the Forster die without the expander ball, and instead use the mandrel. But the rifle and the target didn’t like that. I’m still not sure what that’s about. Only other thing I could try is a .001 mandrel since I have it too.

I just can’t imagine work hardening making a load more consistent. I think you said you tried working the annealed brass in the Forster die and it didn’t help didn’t you? That eliminates that theory if so. Even if you did and it fixed it I would say the expander ball is just ironing out the mouth to lessen the friction on the bullet.

Sometimes annealed necks do not hold powder lube at all. It just falls right off. I would try a hard brush with the graphite on it to coat the heck out of the mouth and a ee if that makes a difference.

Are you sure you aren’t over annealing them?

 

[j-dubya]

I just can’t imagine work hardening making a load more consistent. I think you said you tried working the annealed brass in the Forster die and it didn’t help didn’t you? That eliminates that theory if so. Even if you did and it fixed it I would say the expander ball is just ironing out the mouth to lessen the friction on the bullet.

Sometimes annealed necks do not hold powder lube at all. It just falls right off. I would try a hard brush with the graphite on it to coat the heck out of the mouth and a ee if that makes a difference.

Are you sure you aren’t over annealing them?

Regardless of neck lube, the brass gets something through it whether it be the expander ball or the mandrel. One just makes straighter ammo. The only thing I’m thinking of now is to go measure the expander ball. Perhaps after the large sizing movement of the Forster die, my .002 mandrel is allowing the spring back to be a different dimension than what the complete Forster die provides. Maybe the .001 mandrel will better duplicate what the Forster expander ball does for final neck tension. I’ll do that when I get home tomorrow. I’m just stumped that the Forster die combined with the mandrel goes to shit, but the Forster die and it’s expander ball makes awesome shooting ammo. That’s why I think it’s a tension issue, hence why if I use a smaller bushing, I can recreate the level of tension the whole Forster die provides.

 

[Precision Underground]

Regardless of neck lube, the brass gets something through it whether it be the expander ball or the mandrel. One just makes straighter ammo. The only thing I’m thinking of now is to go measure the expander ball. Perhaps after the large sizing movement of the Forster die, my .002 mandrel is allowing the spring back to be a different dimension than what the complete Forster die provides. Maybe the .001 mandrel will better duplicate what the Forster expander ball does for final neck tension. I’ll do that when I get home tomorrow. I’m just stumped that the Forster die combined with the mandrel goes to shit, but the Forster die and it’s expander ball makes awesome shooting ammo. That’s why I think it’s a tension issue, hence why if I use a smaller bushing, I can recreate the level of tension the whole Forster die provides.

Does the brass shoot good when annealed and then run through the Forster? If so look and see if your expander has lube on it. Mine stays pretty slippery. That or I would guess the ball is more rough than the mandrel so it is sort of sanding the inside of the mouth.

 

[918v]

Annealing increases friction inside the neck. The solution is imperial graphite neck lube.

 

[straightshooter1]

Annealing increases friction inside the neck. The solution is imperial graphite neck lube.

. . . . or, clean the brass AFTER you anneal.

 

[Snuby642]

I'm having neck tension issues as well.
Fc gmm brass same gun now not getting the 0.002 as was.

First fireds no annealing.

 

[Dthomas3523]

If it’s in the budget, get a hydro press or a k&m press with gauge.

You’ll likely see that it takes more seating pressure after annealing if you don’t clean or use neck lube after.

Many times neck tension and seating pressure(friction) are not the same.

 

[j-dubya]

I think we are still not understanding each other. My process has been identical between the two loading s with the exception of annealing when switching from the Forster FL die and the Redding bushing die and mandrel. Exact process is as follows:

The known good load-
Quick clean
AMP anneal
Imperial wax and size with Forster FL die - fired neck at .344ish, .321 compression, .336 expansion
Quick primer pocket scrape
Trim and chamfer
Full graphite treatment of neck
Bullet seating

The new process where things have fallen apart-
Quick clean
AMP anneal
Imperial wax and size with Redding bushing FL die - .344 fired neck, .3335 compression, .336 expansion
Imperial graphite from media applicator on the neck, a couple of quick rolls
.002 mandrel, TiN coated
Primer pocket scrape
Trim and chamfer
Full graphite treatment of neck
Bullet seating

The load returns to not just normal but slightly improved when the annealing step is removed from that new process and the brass is processed as “once fired”. At that point the new sized dimensions measure .3325 compression, .335 expansion. That is the ONlY difference noted throughout the entire process. No arbor press yet, but I can note an ever so slightly less force required for seating when using the annealed brass.

This is why I am suspect of work hardening. It’s the only thing that has been changed/affected.

 

[Tokay444]

You say that annealing is the difference between the two loading techniques, but then include annealing in both techniques, in the same post. If we’re not understanding, it’s because you’re confusing the situation.
Is annealing the exception or not?

I think we are still not understanding each other. My process has been identical between the two loading s with the exception of annealing when switching from the Forster FL die and the Redding bushing die and mandrel. Exact process is as follows:

The known good load-
Quick clean
AMP anneal
Imperial wax and size with Forster FL die - fired neck at .344ish, .321 compression, .336 expansion
Quick primer pocket scrape
Trim and chamfer
Full graphite treatment of neck
Bullet seating

The new process where things have fallen apart-
Quick clean
AMP anneal
Imperial wax and size with Redding bushing FL die - .344 fired neck, .3335 compression, .336 expansion
Imperial graphite from media applicator on the neck, a couple of quick rolls
.002 mandrel, TiN coated
Primer pocket scrape
Trim and chamfer
Full graphite treatment of neck
Bullet seating

 

[Precision Underground]

You say that annealing is the difference between the two loading techniques, but then include annealing in both techniques, in the same post. If we’re not understanding, it’s because you’re confusing the situation.
Is annealing the exception or not?

I think he is saying when he removes annealing from the second process the load shoots. I think lol.

OP- your expander is likely adding lube or smoothing out the rough surface of the neck. The TIN coated expander is not. Try adding a tiny bit of wax/lube that will not affect powder and brush the crap out of the neck and see if it makes a difference. That will tell you if friction is the culprit. IME dry lube does not stick to annealed mouths very well at all.

 

[Snuby642]

The dry lube sticks to bullets well enough, you can see it.

I changed tumbler media and it is more aggressive cleaning the inside of the neck. I think there has been a 0.001 change in neck tension.

One thing I do have many years worth of experience on is forming metals, over 30 years.

First fired, one temper, you get a set amount of spring back.
Twice fired a different amount of temper, new set back..
Annealed, different temper altogether.

If you're annealing process is steady you can accommodate a good neck tension, but will need a different expander looks like. Easily done with 400 grit emory cloth.

It's the amount of spring back from different brass tempers doing it.

 

[918v]

. . . . or, clean the brass AFTER you anneal.

It doesn’t work as well as graphite

 

[j-dubya]

I think he is saying when he removes annealing from the second process the load shoots. I think lol.

OP- your expander is likely adding lube or smoothing out the rough surface of the neck. The TIN coated expander is not. Try adding a tiny bit of wax/lube that will not affect powder and brush the crap out of the neck and see if it makes a difference. That will tell you if friction is the culprit. IME dry lube does not stick to annealed mouths very well at all.

So when the mandrel is used again on the brass without the annealing step, why is it back to being smooth enough in the neck that the load performs its best out of all three styles? To me, I’m looking at the numbers of the neck, based on the amount of work hardening it’s experiencing through the three processes. Am I the only one that thinks that what’s playing the part here...?

 

[918v]

I think he is saying when he removes annealing from the second process the load shoots. I think lol.

OP- your expander is likely adding lube or smoothing out the rough surface of the neck. The TIN coated expander is not. Try adding a tiny bit of wax/lube that will not affect powder and brush the crap out of the neck and see if it makes a difference. That will tell you if friction is the culprit. IME dry lube does not stick to annealed mouths very well at all.

Sure it does. You just need to apply it correctly. You can feel the difference when seating the bullets. There is much less seating pressure. The seater stem no longer leaves marks on the bullet nose.

 

[j-dubya]

The dry lube sticks to bullets well enough, you can see it.

I changed tumbler media and it is more aggressive cleaning the inside of the neck. I think there has been a 0.001 change in neck tension.

One thing I do have many years worth of experience on is forming metals, over 30 years.

First fired, one temper, you get a set amount of spring back.
Twice fired a different amount of temper, new set back..
Annealed, different temper altogether.

If you're annealing process is steady you can accommodate a good neck tension, but will need a different expander looks like. Easily done with 400 grit emory cloth.

It's the amount of spring back from different brass tempers doing it.

So when you look at the measurements I posted above and their differences from the amount of forming the dies perform on them, do you think I’m am of the correct assumption this is a work hardening issue which translates directly to the final tension variation between the good load and bad load? Annealed brass that gets worked twice as hard in the Forster FL die makes the load shoot well. Take an annealed Case and go through the processing twice - each with only a small portion of movement during the sizing - and the load returns to normal.

 

[straightshooter1]

It doesn’t work as well as graphite

True. But, too little friction can present a problem of it's own, huh?

 

[Precision Underground]

So when the mandrel is used again on the brass without the annealing step, why is it back to being smooth enough in the neck that the load performs its best out of all three styles? To me, I’m looking at the numbers of the neck, based on the amount of work hardening it’s experiencing through the three processes. Am I the only one that thinks that what’s playing the part here...?

Because annealing it is what’s causing the neck to have too much friction. If you annealed, sized down with the forster with no expander, then ran the mandrel, you just worked the brass the same amount as you would have if you used the expander ball and it still is not shooting good. I think your expander ball is either lubed or is rough enough to sand the inside of the case mouth and reduce friction on the bullet.

 

[j-dubya]

Because annealing it is what’s causing the neck to have too much friction. If you annealed, sized down with the forster with no expander, then ran the mandrel, you just worked the brass the same amount as you would have if you used the expander ball and it still is not shooting good. I think your expander ball is either lubed or is rough enough to sand the inside of the case mouth and reduce friction on the bullet.

The expander ball has been polished. Back when I was messing around with trying to make life easier withe the stainless tumbled brass, I would have to routinely polish and remove brass residue buildup after wrestling it back through the super clean necks. The only thing I can think of that would apply to what you’re saying is the expander ball technically has less “bearing surface” than the mandrel that the neck experiences. But it seems to me the carbon left on the neck along with the application of graphite prior to the mandrel making its pass would negate in major differences. Again, the difference in the neck measurements - likely due to spring back differences between the two methods - and the difference in grip on the bullet is what I’m seeing what’s most accountable here.

Again, two cycles of processing that minimizes compression and expansion as compared to the Forster FL die: process - fire - process ——> brings everything back in line and even slightly better results than the original Forster load with its .004 runout.

ETA - the expanderless Forster sized brass has only been tested with the .002 mandrel. Perhaps the .001 mandrel is a better match to the Forster expander ball when combined with the spring back. I just realized that last night and have not measured or tested that variable yet. I will do this tonight when I get home.

 

[Tokay444]

Have you pin gauged your sized brass to know exactly how much tension you're actually running, for any of your 3 methods?
If not, then this entire thread is moot.

 

[918v]

True. But, too little friction can present a problem of it's own, huh?

Yes, but...

Graphite in no way creates too little friction. Sizing wax would create too little friction, tho.

 

[Precision Underground]

The expander ball has been polished. Back when I was messing around with trying to make life easier withe the stainless tumbled brass, I would have to routinely polish and remove brass residue buildup after wrestling it back through the super clean necks. The only thing I can think of that would apply to what you’re saying is the expander ball technically has less “bearing surface” than the mandrel that the neck experiences. But it seems to me the carbon left on the neck along with the application of graphite prior to the mandrel making its pass would negate in major differences. Again, the difference in the neck measurements - likely due to spring back differences between the two methods - and the difference in grip on the bullet is what I’m seeing what’s most accountable here.

Again, two cycles of processing that minimizes compression and expansion as compared to the Forster FL die: process - fire - process ——> brings everything back in line and even slightly better results than the original Forster load with its .004 runout.

ETA - the expanderless Forster sized brass has only been tested with the .002 mandrel. Perhaps the .001 mandrel is a better match to the Forster expander ball when combined with the spring back. I just realized that last night and have not measured or tested that variable yet. I will do this tonight when I get home.

Ehh. I’m picturing it sanding the necks on a microscopic level. Polishing the expander doesn’t mean it’s as smooth as the TiN. I don’t think expanding an extra .001 is going to make a difference in work hardening on one pass. IMO the issue is not too much or too little friction. It’s inconsistent friction. Annealing is leaving inconsistencies inside the neck and the expander is ironing them out.

Anneal some and use a tiny bit of sizing wax that won’t hurt powder and brush the heck out of the necks before expanding and then wipe it out good. This will tell you if friction is the cause.

 

[smoooth1]

Easier yet, just use the process that SHOOTS BEST and eliminate the headaches and sleepless nights lost over some pieces of brass

More steps in a process, does not a better process make

 

[Precision Underground]

Easier yet, just use the process that SHOOTS BEST and eliminate the headaches and sleepless nights lost over some pieces of brass

More steps in a process, does not a better process make

This too. .002 runout is not going to matter on the target unless you are trying to shoot benchrest.

 

[j-dubya]

Have you pin gauged your sized brass to know exactly how much tension you're actually running, for any of your 3 methods?
If not, then this entire thread is moot.

No pin gauges, but post #15 has the info you seek on measured OD’s. I think this thread has quite a bit of info in it to not be moot...

 

[Snuby642]

So when you look at the measurements I posted above and their differences from the amount of forming the dies perform on them, do you think I’m am of the correct assumption this is a work hardening issue which translates directly to the final tension variation between the good load and bad load? Annealed brass that gets worked twice as hard in the Forster FL die makes the load shoot well. Take an annealed Case and go through the processing twice - each with only a small portion of movement during the sizing - and the load returns to normal.

So the first reload and second reload after annealing are the sweet spot?
What I'm hearing is the fresh annealed are the problem child.

Regardless of cleaning and how you set the neck.
To get back to a favorable neck tension the first load after annealing will need more measured tension since it is softer.
Get a new expander and take off 0.001 thousands more than your normal.
Eventually you will get the same actual tension reguardless of measurement.

I know this can be done with the other dies but I like to compare apples to apples.

 

[j-dubya]

Ehh. I’m picturing it sanding the necks on a microscopic level. Polishing the expander doesn’t mean it’s as smooth as the TiN. I don’t think expanding an extra .001 is going to make a difference in work hardening on one pass. IMO the issue is not too much or too little friction. It’s inconsistent friction. Annealing is leaving inconsistencies inside the neck and the expander is ironing them out.

Anneal some and use a tiny bit of sizing wax that won’t hurt powder and brush the heck out of the necks before expanding and then wipe it out good. This will tell you if friction is the cause.

I’m following now. I will make up some rounds with the necks cleaned out.

As for the runout, the Forster die keeps things up around .004 runout. The die is fine for dry tumbled brass with carbon’d necks, but is atrocious in both sizing and shooting for stainless tumbled brass. In a search for finding a better way to size with the mandrel for the stainless brass so I can get some use out of it, doing this method on the regular brass and just trying to duplicate what the Forster does since runout is down to .001-.0015. While it’s for a gas gun yada yada yada, I still want to know what the difference is here simply because of the science.

 

[j-dubya]

So the first reload and second reload after annealing are the sweet spot?
What I'm hearing is the fresh annealed are the problem child.

Regardless of cleaning and how you set the neck.
To get back to a favorable neck tension the first load after annealing will need more measured tension since it is softer.
Get a new expander and take off 0.001 thousands more than your normal.
Eventually you will get the same actual tension reguardless of measurement.

I know this can be done with the other dies but I like to compare apples to apples.

Annealing and then overworking the brass through FORster die is where the load was developed and shoots well. Annealing and then minimizing the amount of work performed on the brass via a bushing die is where I’ve run into trouble. Take those same trouble-rounds’ brass after firing and go through the exact same process again minus the annealing step, in other words doubling up on the amount of work performed on the brass via the minimized sizing from the bushing die since the last annealing operation, and POOF - the load shoots the same if not slightly better than the original good load.

Post #15 outlined it, but the Forster die compresses the neck an extra .012 as opposed to the bushing die. To me, the Forster die has induced more work on that brass by the time expansion takes place, and that’s what the developed load likes. All I’m trying to figure out is how to duplicate that with the mandrel so I get straighter ammo.

 

[Precision Underground]

I’m following now. I will make up some rounds with the necks cleaned out.

As for the runout, the Forster die keeps things up around .004 runout. The die is fine for dry tumbled brass with carbon’d necks, but is atrocious in both sizing and shooting for stainless tumbled brass. In a search for finding a better way to size with the mandrel for the stainless brass so I can get some use out of it, doing this method on the regular brass and just trying to duplicate what the Forster does since runout is down to .001-.0015. While it’s for a gas gun yada yada yada, I still want to know what the difference is here simply because of the science.

Just use wax inside the neck when you size the stainless brass. That should make it size a lot easier. This is why I only dry tumble and do not sonic clean. There is no need for brass to be all shiny. It looks pretty but makes things a lot more complicated.

 

[j-dubya]

Just use wax inside the neck when you size the stainless brass. That should make it size a lot easier. This is why I only dry tumble and do not sonic clean. There is no need for brass to be all shiny. It looks pretty but makes things a lot more complicated.

I originally stainless tumbled because I had the larger tumbler for doing large batches of dirty 5.56 brass. So I would toss the other calibers in there too since it would clean them and their primer pockets. Many of those loads were bushing sized only, no mandrel or expander, so after graphite they all shot well. As I’ve refined and gone back to expanding, I realized the detriments and stopped, but not before I had a large volume already washed.

Does the wax not make a hassle with getting tumbling media back out? That’s why I’ve always stayed away from experimenting with it. Plus it was one more step in an area I always want to speed up.

 

[Tokay444]

No pin gauges, but post #15 has the info you seek on measured OD’s. I think this thread has quite a bit of info in it to not be moot...

What are you using to measure to the half thou with, and are you assuming it's not deflecting the necks while you're doing it? A pin gauge really is the correct method.

 

[Steel head]

Just use wax inside the neck when you size the stainless brass. That should make it size a lot easier. This is why I only dry tumble and do not sonic clean. There is no need for brass to be all shiny. It looks pretty but makes things a lot more complicated.

I pretty much eliminated cleaning brass at all unless it gets muddy.
My pigpen brass shoots great before and after annealing

 

[j-dubya]

What are you using to measure to the half thou with, and are you assuming it's not deflecting the necks while you're doing it? A pin gauge really is the correct method.

I know what you’re getting at, and yes, pin gauges would be best. But I’m not intending to have someone else make something or hone something based on their instruments. I simply posted my exact numbers based on my instruments for comparative purposes and use math to describe what I’m seeing. No different than using bullet comparators, I simply aim to replicate the numbers of what works and cross out the numbers that don’t as options.

 

[918v]

Annealing and then overworking the brass through FORster die is where the load was developed and shoots well. Annealing and then minimizing the amount of work performed on the brass via a bushing die is where I’ve run into trouble. Take those same trouble-rounds’ brass after firing and go through the exact same process again minus the annealing step, in other words doubling up on the amount of work performed on the brass via the minimized sizing from the bushing die since the last annealing operation, and POOF - the load shoots the same if not slightly better than the original good load.

Your annealed necks are simply too soft. I would size the case in your Forster die using graphite on the inside of the neck, then apply graphite again prior to bullet seating.

 

[j-dubya]

Your annealed necks are simply too soft. I would size the case in your Forster die using graphite on the inside of the neck, then apply graphite again prior to bullet seating.

Absolutely agree. That’s where my head has been at even before making the thread. But using the Forster to get the load’s desired work hardening, I just wanted to use the mandrel in order to get even straighter ammo. After shooting like crap, I now want to know exactly what the difference between the mandrel from the expander ball is just because of the science.

 

[918v]

So remove the expander ball, size the case, apply graphite to the inside of the neck, expand using the mandrel, then apply graphite again.

 

[j-dubya]

That’s what I did even before I made this thread. It didn’t shoot (with the .002 mandrel). That’s what Precision Underground and myself have been going back and forth about. My only other thing that I somehow forgot to measure, much less test, is trying the .001 mandrel. Perhaps it’s a better match to the expander ball in terms of final spring back. I’m trying that tonight.

So remove the expander ball, size the case, apply graphite to the inside of the neck, expand using the mandrel, then apply graphite again.

 

[ZY100]

Something I stumbled on with AMP annealing. After I AMP anneal, I tumble my brass for 3-4 HOURS in "a bit used" media.

- I after annealing, I full size and then mandrel as a final step
- My rock stable, low ED/SD ( SD typically <10) loads went a little wonky initially with the AMP
- By accident, my 20 minute tumble to get the lube off went ~ 4 hrs on a batch...and suddenly ED/SD dropped right back to normal. (Walnut with polish and a cap or two of nu-finish wax)

My mantra is accurate loads and low ED/SD is all about neck tension and neck friction--and gives nice wide nodes. Regardless, I think the AMP induction annealing may leave the brass with more/less/different oxide than firing or flame annealing.

Anyways, my experience. Try tumbling a few for a few hours with your current annealing process and see what happens...might be the ticket for you too!

ZY

 

[TSloper]

I just recent started getting erratic SD/ES on my 4-5 times fired and annealed (home made induction annealer) LC 18 brass. The charges with the last go around were done with my new FX-120i so it wasn’t that.

I had some pin gauges (minus Z) come in and what I found is that after using a .223 mandrel the .222 pin would enter but was getting hung up completely at the shoulder to neck boundary. Upon closer inspection I found little specs of debris that appear to be fused to the brass. Definitely enough to hang up a close fitting pin. So essentially this would screw up the neck tension. I cleaned up that area and the pin proceeded as it should.

I anneal before SS tumbling. I’m wondering if residue is baking on at 1000F during annealing. I still need to do some more testing on additional pieces to see if it’s just residue or if a donut is forming. If it’s residue I’ll start brushing the necks before annealing and see how it goes.

Pin gauges are worth having. Z class on McMaster are relatively inexpensive. The .0005 increments should be in this week.

 

[Precision Underground]

That’s what I did even before I made this thread. It didn’t shoot (with the .002 mandrel). That’s what Precision Underground and myself have been going back and forth about. My only other thing that I somehow forgot to measure, much less test, is trying the .001 mandrel. Perhaps it’s a better match to the expander ball in terms of final spring back. I’m trying that tonight.

A .001 difference is not going to matter when it comes to once cycle of work hardening freshly annealed brass. It can matter when it comes to neck tension but .001 more or less tension is not going to make a load go to hell. You have something adding inconsistency. .001 tension across the board is not going to do that. It may change your numbers but it wouldn't show up on target IMO. It's easy to miss the forest for the trees and get hung up on a thou here and a thou there because you are looking at whole numbers on a caliper. Open your calipers up so they say .001 and look at the size of it. That is not going to affect work hardening at all in one cycle.

The biggest difference in the two loads is not a thou or two of work hardening or tension it is that you are pulling/pushing through 2 completely different tools that are made of completely different materials with completely different shapes and completely different frictional properties. Add in that annealed brass is known to give issues with friction in the neck and you have your answer.

And I am heavily invested in this now you have to figure it out soon and report back lol.

 

[TSloper]

Ok so scrap what I said in my previous post. I spent some quality time on my gauge pin issue after my last post. While there was some teensy tiny debris in that area removing it with some 0000 steel wool had absolutely no impact on allowing the pin to proceed without a hard stop. I should have tested that further before posting what I did but oh well...

I just verified my specific issue is 100% due to insufficient annealing at that location. I reduced my original anneal time from 3.5 seconds to 3.2 seconds a couple firings ago and it induced the problem. I cleaned up a few neck IDs with some 0000 steel wool and tested with the pin. No go on any of them (all same # of firings with annealing each time). I re-ran all of them through the annealer at my original time of 3.5 seconds. I cleaned off the oxide layer with some steel wool and re-ran them through the resizing die and 0.223 mandrel. Bam... all passing the pin perfectly. Simply running the mandrel through without getting the annealing correct at that location had zero impact. The spring back was just too much over 4-5 firings where it was under annealed compared to the rest of the neck.

So I should have just stuck to my original time of 3.5 seconds that I arrived at with 1000F Tempilaq testing. But my error was insightful. I would highly recommend that anyone annealing (flame or induction) get a range of class Z pin gauges and actually check that the internal diameter of the neck is consistent all the way from mouth to shoulder. In my case it was not and without a doubt is the cause of my erratic velocities on this set of brass on the last outing. My new pieces of brass are passing just fine (this set is now using a 0.222 mandrel and passing a 0.221 pin).

I hope this helps. I do not believe any meaningful annealing is happening only hitting 750F if it is momentary in the case of an induction annealer. It has to get up to the 1000F range. Also... never run annealed brass through your die that hasn't had the oxide layer removed (SS tumbling is effective). You WILL screw up your die and cause gaulling on the neck OD. You will then be polishing your die to remove the problem. I made this mistake initially and never had another problem once I stopped running annealed brass through that hadn't been SS tumbled first.

Tim

 

[j-dubya]

A .001 difference is not going to matter when it comes to once cycle of work hardening freshly annealed brass. It can matter when it comes to neck tension but .001 more or less tension is not going to make a load go to hell. You have something adding inconsistency. .001 tension across the board is not going to do that. It may change your numbers but it wouldn't show up on target IMO. It's easy to miss the forest for the trees and get hung up on a thou here and a thou there because you are looking at whole numbers on a caliper. Open your calipers up so they say .001 and look at the size of it. That is not going to affect work hardening at all in one cycle.

The biggest difference in the two loads is not a thou or two of work hardening or tension it is that you are pulling/pushing through 2 completely different tools that are made of completely different materials with completely different shapes and completely different frictional properties. Add in that annealed brass is known to give issues with friction in the neck and you have your answer.

And I am heavily invested in this now you have to figure it out soon and report back lol.

Went back and checked my targets from the other day. I wasn’t clear in my original post, but the Forster/.002 mandrel combo groups shot well and look about as good as the normal load. It’s this load combo where the numbers had grown in every aspect: velocity averages, ES & SD. Not only that, but the velocity averages were erratic from the normal range. So I agree with you and how the slight .001 neck tension difference can screw with the numbers but can’t tell much of a difference on target at 100m.

So I just went and measured and sized with the three variations I can create with the Forster die. This is where it gets interesting now that Precision Underground switched me on to friction. Sizing the variants back to back to back let me notice a significant detail...

Quick dimension rundown:
.001 mandrel, carbide, measures exactly .3070
.002 mandrel, TiN, measures exactly .3055
Forster expander ball, carbide, measures exactly .3065

Forster FL sized brass with expander ball neck OD - .336
Forster sized with .001 carbide mandrel neck OD - .337
Forster sized with .002 TiN mandrel neck OD - .3355

Now the good part, with a big thanks to Precision Underground for raising the detail... the TiN mandrel had a noticeable amount of increased resistance over the carbide mandrel and carbide expander ball when inserting and extracting from the neck. No graphite was applied to the Forster die with expander ball in place, as has been my routine. Graphite applied to both mandrel operations, and the TiN mandrel has a noticeable increase in resistance over the other two methods, even the Forster expander ball with no graphite. I was only able to note this because I was doing all the methods right after one another, five pieces of brass each.

So Precision Underground, friction is at play here like you thought, in addition to neck tension differences. I’m taking the carbide mandrel to a machine shop tomorrow to have them match its OD to the Forster expander ball. That should make our winning combo.

 

[Precision Underground]

Went back and checked my targets from the other day. I wasn’t clear in my original post, but the Forster/.002 mandrel combo groups shot well and look about as good as the normal load. It’s this load combo where the numbers had grown in every aspect: velocity averages, ES & SD. Not only that, but the velocity averages were erratic from the normal range. So I agree with you and how the slight .001 neck tension difference can screw with the numbers but can’t tell much of a difference on target at 100m.

So I just went and measured and sized with the three variations I can create with the Forster die. This is where it gets interesting now that Precision Underground switched me on to friction. Sizing the variants back to back to back let me notice a significant detail...

Quick dimension rundown:
.001 mandrel, carbide, measures exactly .3070
.002 mandrel, TiN, measures exactly .3055
Forster expander ball, carbide, measures exactly .3065

Forster FL sized brass with expander ball neck OD - .336
Forster sized with .001 carbide mandrel neck OD - .337
Forster sized with .002 TiN mandrel neck OD - .3355

Now the good part, with a big thanks to Precision Underground for raising the detail... the TiN mandrel had a noticeable amount of increased resistance over the carbide mandrel and carbide expander ball when inserting and extracting from the neck. No graphite was applied to the Forster die with expander ball in place, as has been my routine. Graphite applied to both mandrel operations, and the TiN mandrel has a noticeable increase in resistance over the other two methods, even the Forster expander ball with no graphite. I was only able to note this because I was doing all the methods right after one another, five pieces of brass each.

So Precision Underground, friction is at play here like you thought, in addition to neck tension differences. I’m taking the carbide mandrel to a machine shop tomorrow to have them match its OD to the Forster expander ball. That should make our winning combo.

I love a good mystery! Are you not lubricating inside the necks at all on the Forster? I would guess that is contributing to the little bit of runout. Any time I am using FL with an expander I dab the neck when I feel the expander starting to drag. Most of the time it’s every 15-20 cases. That expander dragging up on the neck can cause runout.

 

[j-dubya]

I love a good mystery! Are you not lubricating inside the necks at all on the Forster? I would guess that is contributing to the little bit of runout. Any time I am using FL with an expander I dab the neck when I feel the expander starting to drag. Most of the time it’s every 15-20 cases. That expander dragging up on the neck can cause runout.

Not lubricating the fired, dry tumbled cases. They size just fine. It’s the squeaky clean stainless tumbled brass that gives fits using the FL die, which is why I wanted to go back to a bushing and mandrel process. That’s the whole reason this conundrum got started was when I wanted to check the new process on the known load with its brass. Negative results are due to the TiN mandrel. I’m realizing now that the stainless brass I should going to require a new mini-load development. The necks are too different changing the load’s balance, even when lubing each neck.

By the way, I’m back to enjoying my Forster die and why I’ve always used it: nice low runout in one single pass through the press. All the messing around lately had moved the stem around from its optimum position. Once I realized that, I re-set it up and runout is back to all under .002. Doesn’t do anything for the stainless brass, but I am going to attempt to retune it with different bushings, load development, and the correct .002 mandrel in carbide. Each neck will be lubed too.