New RCBS "AR" .308 SB FL Resizer issues

Bill Reid · December 24, 2013, 12:04 AM

... it appears the expander ball is not centered on the shaft causing issues with neck concentricity.

Reloading for Semi-Auto...

Situation... I have some 30.06 62 LC Match brass I converted to 8X57 and set the shoulder too low... so kept it to convert to .308.

Anyway, I tested a few cartridges by pushing the shoulder down to .308 specs using a new RCBS SB FL resizer and checked neck concentricity. I get .005" out (.010+ full sweep). I pull the expander ball out and run another cartridge through and check concentricity and I'm at most .001 (.002 full sweep). I run that exact cartridge back through with expander ball in and its back out to .0045". I pulled the rod/expander ball assembly out and rolled it across a granite counter top... I can see it out of round.

Anybody having issues with the expander ball not being perfectly concentric? I can take the die set back and get another... but what are folks doing that have seen this? Order 3-5 expander balls and use the one that gives best results?

Thanks,
Bill

mehavey · December 24, 2013, 03:17 AM

Before you do that, fully size the case & neck. Leave the ram up.
Before you pull the expander back through, loosen the stem nut a smidge.
Start to pull the expander ball through and to allow it to center itself as it enters the neck.
Tighten the stem nut at that point and finish withdrawal.

Lube/Size a few after that and see if run-out improved.

F. Guffey · December 24, 2013, 08:53 AM

From 30/06 to 8mm57 to 308 W...and? the necks are out .005".

A builder of bench rest type 308 rifles ask for help with a perceived problem, someone purchased one of his rifles, took it to the range fired it and has not quit smiling. Upon his return from the range he decided to reload his fired cases, and oh! the horror, the necks, the necks, according to the Internet reloading forum he was on informed him the neck of the chamber was toooooo large in diameter.

Back to perceived problem. The proud new owner did not know he could stack bullets upon bullets, shot after shot because? He had never owned a rifles that had the ability to stack bullets one on top of the other.

The builder does not do the Internet and had no clue what the problem was, so he called me. I told him we could address the perceived problem by increasing the thickness of the neck. I formed cases that were .003" smaller in diameter than the neck of the chamber when loaded.

Difference, I form with forming dies, I went from 30/06 to 308W then finished the case with the final sizing die.

I have no clue how you formed your cases, I believe you did an outstanding job when you went from 30/06 to 8mm57 to 308W with only .005" run out.

The proud new owner of the bench rest type rifle did not measure the cases before firing, he did not measure run-out, anywhere on the case. As to improving accuracy? I was asked to tighten the fit between the case neck and chamber neck. I did that.

F. Guffey

Bart B. · December 24, 2013, 09:01 AM

With the case wall thickness of military .30-06 brass sized down to .308 Win dimensions, your .308 case neck wall thickness may be thick enough to cause neck bending problems moreso than if they were thinner. And an out of round expander ball would compound the issue.

I'd get another expander for your die and see if it's more round. Turning the case necks to no more than .013" thick would also help. The first .308 Win. cases I ever used were made from LC 30-06 match brass and I had similar problems with reasonably round expander balls. Borrowing a neck turning tool solved that problem.

higgite · December 24, 2013, 09:06 AM

If mehavey's and Bart's suggestions don't fix the problem, call RCBS. It's been my experience that they will probably send you a new expander rod on their dime. Let us know how it works out.

P.S. Welcome to the forum.

F. Guffey · December 24, 2013, 09:10 AM

Before you do that? Sounds like "Who say that".

Before you do what Mehavey said to do, do this, raise the ram, stop, then drop the primer punch/neck sizer ball assemble onto the case before then lower the ram. When the case is out of the die with the assemble rattling around measure the neck for run out, if the case has neck run out before lowering the ram you/we can not blame the neck sizer button,

More complicated, there is 'ME', then there is everyone else. If you can measure the length of the case from the shoulder/datum and the length of the case from the end of the neck to the case head you can determine if pulling the sizer ball through the neck increases the length of the case by pulling the neck away from the case body of 'whatever' . When I pull the sizer ball through the neck my cases get shorter.

Again, it is complicated, it is necessary to feed the sizer ball stem up through the die and secure with the lock nut, this procedure will allow you to pull the assemble through the neck when the ram is lowered.

F. Guffey

F. Guffey · December 24, 2013, 09:22 AM

Before you do that, do that, there are other methods and or techniques, not practiced by other reloaders, I, on occasions. punch primers out for tumbling, then lube and size.

What does that do for me? I can shorten the distance the sizer ball is from the bottom of the case. At one time this method would eliminate the clunk-clunk as in time between the case being removed from the die and the sizer ball hitting the neck. The shorter distance also reduces concentricity, it is just one of those things that may not help but can not hurt.

F. Guffey

F. Guffey · December 24, 2013, 09:49 AM

Then? Collectively we all need to get together and think, The cases went from 30/06 to 8mm57 to 308 W as in finishing with a small base die. A case when manufacturer goes through a few procedures and is annealed at least 5 times and sometimes 6, is it just me? Is it just me? Or is there anyone else out there that thinks the case has stress built up that could cause problems later.

For all of his efforts I would caution him about split necks, after all his shoulder was part of the case body and his necks were also part of the case body with the exception of a few thousands of the shoulder.

So I would suggest he load a few cases and put them aside for observation, I would suggest he check for cracks in the neck before firing. I have cases that have no memory of ever having been something else, it is as though the memory was knocked out of them when fired.

Annealing, hammering by firing and sizing works the brass, annealing does more for removing the memory of the case than firing and sizing.

F. Guffey

AllenJ · December 24, 2013, 10:35 AM

Quote:

rolled it across a granite counter top... I can see it out of round.

If you can see that it is out of round there is an issue. Have you checked it on your concentricity gauge to confirm? As stated above call RCBS, their customer service is second to none in my experience.

Bill Reid · December 24, 2013, 10:44 AM

mehavey,
I tried loosening the expander rod, lowering the ram until I feel contact with expander ball, then tighten, then finish lowering the ram. There is no improvement. If I leave the expander rod assembly loose in the die and cycle a cartridge through I can get down to .003.

F. Guffey,
Are you saying that .005 runout is not something I should worry about when converting brass? Worry about it after fire forming it?

Bart B.,
I do have a K&M neck turning setup. I didn't think it would work but tried it anyway. I turned the case neck, and although there was some thickness variation, the runout really did not improve.

higgite,
Thanks for the recommendation... and thanks for the welcome.

F. Guffey,
What is the difference of forming, essentially an 8X57 case into .308, without an expander rod assembly in place versus forming the case with the expander rod in place then dropping it out prior to lowering the ram and check concentricity? The 8X57 neck never comes into contact with the expander ball when raising the ram. Sorry if I'm not following you... just can't visualize the expander ball causing the problem when raising the ram in this particular situation.

I deprime separately with a universal decapper... then clean as you do. I really like the idea of raising the expander ball closer to the neck in the die to reduce concentricity. I'll try that.

Yes, I anneal prior to converting brass.

Thank You for the advice... it is greatly appreciated.

mehavey · December 24, 2013, 10:46 AM

Bart also brought up the fact that the brass itself may have non-symmetrical neck wall thickness.
In that case the expander may be in-fact centering the hole, but the walls show out-of-round when rolled.

Bill Reid · December 24, 2013, 10:55 AM

AllenJ,
Excellent question! No, I did not check the expander assembly concentricity until you asked

The rod measures slightly less than .001 runout. The expander ball measures .003 runout.

(edit)... I counted full sweep at first.

So, with .003 runout... is that enough to ask RCBS for another expander ball?

Bill Reid · December 24, 2013, 11:07 AM

mehavey,
That is a possibility. I could try converting the brass without an expander assembly, use the K&M expanding mandrel to prep the neck, turn the neck, then run the cartridge back through the reisizing die with the expander assembly in place. Thoughts on that?

I have brand new .308 brass to load and could just use that for reloading... but I enjoy trying to figure out problems like this even if I am inducing them by cartridge conversion

Lucky me... RCBS is closed today and through January 1. So, I think I'll just wait until they come back from the holiday break and give them a call.
Thanks,
Bill

AllenJ · December 24, 2013, 11:16 AM

I do not know what tolerances they strive for but I would not hesitate to ask:

http://www.rcbs.com/general/ask.aspx

higgite · December 24, 2013, 11:23 AM

Okay, since no one else has asked the obvious, I will. ("Obvious" as in it only took me 3 hours to think of it.

) Have you resized any standard .308 brass to see if it's truly a die problem or maybe a downsized brass problem?

Bart B. · December 24, 2013, 11:53 AM

For what it's worth, I'll inject into this thread that the straightest bottleneck fired cases resized for reloading, the use of a full length sizing die whose neck is a couple thousandths smaller than that of a loaded round is used that also sets the case shoulder back a thousandth or two, has been with a gelded die full length sizing die. No ball whatsoever.

If an expander ball's used, it helps keep sized case necks straight if their neck's inside is lubed a tiny bit; all the way back to the throat where the expander ball first enters the neck on its way up through it. Just clean that lube out completely before putting the three P's in the case; primer, powder and projectile.

December 24, 2013, 12:04 AM	#1
Bill Reid Junior Member Join Date: December 15, 2013 Location: Chandler, AZ Posts: 4	New RCBS "AR" .308 SB FL Resizer issues ... it appears the expander ball is not centered on the shaft causing issues with neck concentricity. Reloading for Semi-Auto... Situation... I have some 30.06 62 LC Match brass I converted to 8X57 and set the shoulder too low... so kept it to convert to .308. Anyway, I tested a few cartridges by pushing the shoulder down to .308 specs using a new RCBS SB FL resizer and checked neck concentricity. I get .005" out (.010+ full sweep). I pull the expander ball out and run another cartridge through and check concentricity and I'm at most .001 (.002 full sweep). I run that exact cartridge back through with expander ball in and its back out to .0045". I pulled the rod/expander ball assembly out and rolled it across a granite counter top... I can see it out of round. Anybody having issues with the expander ball not being perfectly concentric? I can take the die set back and get another... but what are folks doing that have seen this? Order 3-5 expander balls and use the one that gives best results? Thanks, Bill

December 24, 2013, 08:53 AM	#3
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	From 30/06 to 8mm57 to 308 W...and? the necks are out .005". A builder of bench rest type 308 rifles ask for help with a perceived problem, someone purchased one of his rifles, took it to the range fired it and has not quit smiling. Upon his return from the range he decided to reload his fired cases, and oh! the horror, the necks, the necks, according to the Internet reloading forum he was on informed him the neck of the chamber was toooooo large in diameter. Back to perceived problem. The proud new owner did not know he could stack bullets upon bullets, shot after shot because? He had never owned a rifles that had the ability to stack bullets one on top of the other. The builder does not do the Internet and had no clue what the problem was, so he called me. I told him we could address the perceived problem by increasing the thickness of the neck. I formed cases that were .003" smaller in diameter than the neck of the chamber when loaded. Difference, I form with forming dies, I went from 30/06 to 308W then finished the case with the final sizing die. I have no clue how you formed your cases, I believe you did an outstanding job when you went from 30/06 to 8mm57 to 308W with only .005" run out. The proud new owner of the bench rest type rifle did not measure the cases before firing, he did not measure run-out, anywhere on the case. As to improving accuracy? I was asked to tighten the fit between the case neck and chamber neck. I did that. F. Guffey Last edited by F. Guffey; December 24, 2013 at 08:58 AM. Reason: change 8 to 6 and G to F

December 24, 2013, 11:07 AM	#13
Bill Reid Junior Member Join Date: December 15, 2013 Location: Chandler, AZ Posts: 4	mehavey, That is a possibility. I could try converting the brass without an expander assembly, use the K&M expanding mandrel to prep the neck, turn the neck, then run the cartridge back through the reisizing die with the expander assembly in place. Thoughts on that? I have brand new .308 brass to load and could just use that for reloading... but I enjoy trying to figure out problems like this even if I am inducing them by cartridge conversion Lucky me... RCBS is closed today and through January 1. So, I think I'll just wait until they come back from the holiday break and give them a call. Thanks, Bill Last edited by Bill Reid; December 24, 2013 at 11:14 AM.

December 24, 2013, 03:17 AM	#2
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,883	Before you do that, fully size the case & neck. Leave the ram up. Before you pull the expander back through, loosen the stem nut a smidge. Start to pull the expander ball through and to allow it to center itself as it enters the neck. Tighten the stem nut at that point and finish withdrawal. Lube/Size a few after that and see if run-out improved.

December 24, 2013, 09:01 AM	#4
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	With the case wall thickness of military .30-06 brass sized down to .308 Win dimensions, your .308 case neck wall thickness may be thick enough to cause neck bending problems moreso than if they were thinner. And an out of round expander ball would compound the issue. I'd get another expander for your die and see if it's more round. Turning the case necks to no more than .013" thick would also help. The first .308 Win. cases I ever used were made from LC 30-06 match brass and I had similar problems with reasonably round expander balls. Borrowing a neck turning tool solved that problem.

December 24, 2013, 09:06 AM	#5
higgite Senior Member Join Date: October 21, 2010 Posts: 1,025	If mehavey's and Bart's suggestions don't fix the problem, call RCBS. It's been my experience that they will probably send you a new expander rod on their dime. Let us know how it works out. P.S. Welcome to the forum.

December 24, 2013, 09:10 AM	#6
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Before you do that? Sounds like "Who say that". Before you do what Mehavey said to do, do this, raise the ram, stop, then drop the primer punch/neck sizer ball assemble onto the case before then lower the ram. When the case is out of the die with the assemble rattling around measure the neck for run out, if the case has neck run out before lowering the ram you/we can not blame the neck sizer button, More complicated, there is 'ME', then there is everyone else. If you can measure the length of the case from the shoulder/datum and the length of the case from the end of the neck to the case head you can determine if pulling the sizer ball through the neck increases the length of the case by pulling the neck away from the case body of 'whatever' . When I pull the sizer ball through the neck my cases get shorter. Again, it is complicated, it is necessary to feed the sizer ball stem up through the die and secure with the lock nut, this procedure will allow you to pull the assemble through the neck when the ram is lowered. F. Guffey

December 24, 2013, 09:22 AM	#7
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Before you do that, do that, there are other methods and or techniques, not practiced by other reloaders, I, on occasions. punch primers out for tumbling, then lube and size. What does that do for me? I can shorten the distance the sizer ball is from the bottom of the case. At one time this method would eliminate the clunk-clunk as in time between the case being removed from the die and the sizer ball hitting the neck. The shorter distance also reduces concentricity, it is just one of those things that may not help but can not hurt. F. Guffey

December 24, 2013, 09:49 AM	#8
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	Then? Collectively we all need to get together and think, The cases went from 30/06 to 8mm57 to 308 W as in finishing with a small base die. A case when manufacturer goes through a few procedures and is annealed at least 5 times and sometimes 6, is it just me? Is it just me? Or is there anyone else out there that thinks the case has stress built up that could cause problems later. For all of his efforts I would caution him about split necks, after all his shoulder was part of the case body and his necks were also part of the case body with the exception of a few thousands of the shoulder. So I would suggest he load a few cases and put them aside for observation, I would suggest he check for cracks in the neck before firing. I have cases that have no memory of ever having been something else, it is as though the memory was knocked out of them when fired. Annealing, hammering by firing and sizing works the brass, annealing does more for removing the memory of the case than firing and sizing. F. Guffey

December 24, 2013, 10:44 AM	#10
Bill Reid Junior Member Join Date: December 15, 2013 Location: Chandler, AZ Posts: 4	mehavey, I tried loosening the expander rod, lowering the ram until I feel contact with expander ball, then tighten, then finish lowering the ram. There is no improvement. If I leave the expander rod assembly loose in the die and cycle a cartridge through I can get down to .003. F. Guffey, Are you saying that .005 runout is not something I should worry about when converting brass? Worry about it after fire forming it? Bart B., I do have a K&M neck turning setup. I didn't think it would work but tried it anyway. I turned the case neck, and although there was some thickness variation, the runout really did not improve. higgite, Thanks for the recommendation... and thanks for the welcome. F. Guffey, What is the difference of forming, essentially an 8X57 case into .308, without an expander rod assembly in place versus forming the case with the expander rod in place then dropping it out prior to lowering the ram and check concentricity? The 8X57 neck never comes into contact with the expander ball when raising the ram. Sorry if I'm not following you... just can't visualize the expander ball causing the problem when raising the ram in this particular situation. I deprime separately with a universal decapper... then clean as you do. I really like the idea of raising the expander ball closer to the neck in the die to reduce concentricity. I'll try that. Yes, I anneal prior to converting brass. Thank You for the advice... it is greatly appreciated.

December 24, 2013, 10:46 AM	#11
mehavey Senior Member Join Date: June 17, 2010 Location: Virginia Posts: 6,883	Bart also brought up the fact that the brass itself may have non-symmetrical neck wall thickness. In that case the expander may be in-fact centering the hole, but the walls show out-of-round when rolled.

December 24, 2013, 10:55 AM	#12
Bill Reid Junior Member Join Date: December 15, 2013 Location: Chandler, AZ Posts: 4	AllenJ, Excellent question! No, I did not check the expander assembly concentricity until you asked The rod measures slightly less than .001 runout. The expander ball measures .003 runout. (edit)... I counted full sweep at first. So, with .003 runout... is that enough to ask RCBS for another expander ball?

December 24, 2013, 11:16 AM	#14
AllenJ Senior Member Join Date: December 11, 2009 Location: Northern California Posts: 1,766	I do not know what tolerances they strive for but I would not hesitate to ask: http://www.rcbs.com/general/ask.aspx

December 24, 2013, 11:23 AM	#15
higgite Senior Member Join Date: October 21, 2010 Posts: 1,025	Okay, since no one else has asked the obvious, I will. ("Obvious" as in it only took me 3 hours to think of it. ) Have you resized any standard .308 brass to see if it's truly a die problem or maybe a downsized brass problem?

December 24, 2013, 11:53 AM	#16
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	For what it's worth, I'll inject into this thread that the straightest bottleneck fired cases resized for reloading, the use of a full length sizing die whose neck is a couple thousandths smaller than that of a loaded round is used that also sets the case shoulder back a thousandth or two, has been with a gelded die full length sizing die. No ball whatsoever. If an expander ball's used, it helps keep sized case necks straight if their neck's inside is lubed a tiny bit; all the way back to the throat where the expander ball first enters the neck on its way up through it. Just clean that lube out completely before putting the three P's in the case; primer, powder and projectile.