So I had an issue with my full length sizing die. Nothing coming out of it is in SAMMI spec the case bodies are too wide. They have all been run through the die multiple times at this point as I tried to diagnose the initial problem, with and without the decapper installed. Case stick at this point has also resulted in destroying a charging handle and a cleaning rod due to a stuck case. I bought a Sheridan ammo gauge to diagnose the problem and emailed lee about this issue and the dies not reforming the brass into SAMMI spec. This is the reply that I got.
XXXXXXX,
The Lee 300AAC full length sizing die is designed to resize 300AAC cases to pre-fired dimensions. Lee rifle sizing dies do not size the fired case all the way back down to SAAMI minimum. Through experience Lee has found that the chambers of most guns are large enough and sizing the cases to minimum unnecessarily overworks the case and results in shortened case life. The 300AAC full length sizing die is often used to reform 223 or 556 cases to 300AAC cases. Results will vary when this is attempted because the Lee die is a sizing die and not a forming die. Forming dies have smaller dimensions to account for the increased spring back that is encountered when cases are formed. Forming die dimensions are at least at minimum SAAMI if not below. The amount of spring back also varies as a result of case wall thickness or hardness. So you will find that you may be able to reform some cases satisfactorily with a Lee sizing die and others not at all.
Another factor that can come into play is the thickness of the case neck on reformed case. As you leave the neck area of the case and move into the shoulder and body side wall area the brass gradually thickens the closer to the case head you get. When you shorten the 223 or 556 case you begin to get into thicker metal and if it is too thick the loaded diameter of the cartridge neck can become too large and create chambering and live round ejection problems. Not to mention the possibility of dangerously high chamber pressures due to bullet pinch.
Here is the process that seems to work with the greatest degree of success if you wish to attempt to reform cases with your Lee sizing die. Trim the cases and after lubing with Lee Resizing Lube size the cases in the full length die with the decapper/expander rod removed. After this first sizing re-lube the cases and size them one more time with the decapper/expander rod installed. This seems to work for many but not all cases.
Hope this helps.
Thanks,
Peter
Customer Service
Lee Precision, Inc.
4275 Highway U
Hartford, WI 53027
phone: 262-673-3075
Basically Lee will not stand behind or warranty their dies if used for reforming other calibers into the intended caliber. I will be packing up the dies returning them for exchange for an other brand, and advising all I know to not buy Lee for this period.
Moral of the story f you intend to reform 223 or 5.56 brass DO NOT BUY LEE!
Last edited by pyromancer on Fri May 16, 2014 1:03 am, edited 1 time in total.
I figure about 1 in 10 are bad and have been for several years. I have a set of bad dies as well but they do work on looser chambers. If your gun has a whisper chamber, which I suspect a lot of manufacturers do, then you will have problems regardless whether the Lee dies are bad or good.
Make sure that your case holder is touching the die when your ram is at the top of its stroke, then turn the die down at least 1/2 turn past that point.
resize one and check with the Sheridan gauge.
If still doesn't pass, polish down your case holder a bit at a time checking between polishes to see if/when it passes the gauge test or just use another brand case holder. If after all this it doesn't work then I would take them back, but for many of us using the Lee dies this has taken care of the problem. I think it is the 1/2 turn that gets most of us, I had the same issue as you but now have around a thousand converted with no more sizing issues.
"Freedom is the sure possession of those alone who have the courage to defend it."
~Pericles~
Omega wrote:Before you spend any money, try this in sequence:
Make sure that your case holder is touching the die when your ram is at the top of its stroke, then turn the die down at least 1/2 turn past that point.
resize one and check with the Sheridan gauge.
If still doesn't pass, polish down your case holder a bit at a time checking between polishes to see if/when it passes the gauge test or just use another brand case holder. If after all this it doesn't work then I would take them back, but for many of us using the Lee dies this has taken care of the problem. I think it is the 1/2 turn that gets most of us, I had the same issue as you but now have around a thousand converted with no more sizing issues.
I've tried beyond half a turn and everything in between. The issue is not where the neck falls it is the base of the brass is too wide. I sharpied one black to see where the hold up in the Sheridan was. I'm not sure how even a smaller case holder would fix that. I do not want to modify their dies or case holder to make them work, and more so I have a very bad taste in my mouth now for lee with their response.
I think I will give the RCBS small base dies a go.
Omega wrote:Before you spend any money, try this in sequence:
Make sure that your case holder is touching the die when your ram is at the top of its stroke, then turn the die down at least 1/2 turn past that point.
resize one and check with the Sheridan gauge.
If still doesn't pass, polish down your case holder a bit at a time checking between polishes to see if/when it passes the gauge test or just use another brand case holder. If after all this it doesn't work then I would take them back, but for many of us using the Lee dies this has taken care of the problem. I think it is the 1/2 turn that gets most of us, I had the same issue as you but now have around a thousand converted with no more sizing issues.
I've tried beyond half a turn and everything in between. The issue is not where the neck falls it is the base of the brass is too wide. I sharpied one black to see where the hold up in the Sheridan was. I'm not sure how even a smaller case holder would fix that. I do not want to modify their dies or case holder to make them work, and more so I have a very bad taste in my mouth now for lee with their response.
I think I will give the RCBS small base dies a go.
It is a canned response since I got the same message when I contacted them, and for the most part they are right. I am not trying to defend them or anything just letting you know how I got mine to work. Most dies will only go down so far, even the small base dies will only go down so far but do a much better job at forming a 300 from a 5.56. I think on mine it was just the 1/2 turn that was needed, but I mixed up the case holder with my 5.56 set so I polished it a bit anyway. You will do good with the RCBS ones, good luck.
"Freedom is the sure possession of those alone who have the courage to defend it."
~Pericles~
The sizing die MUST touch the shell holder with Lee dies. If it doesn't then the cases are not being sized. And even if you are touching and they are still not small enough then taking some off the top of the shell holder can help.
I was having the same issue with Lee dies and found resizing the .223 brass back to .223 specs before trimming, deburr/dechamfering and forming into 300BO worked wonders. The spring back is a killer, but sizing them incrementally seems to solve it without buying a new set of dies.
At first I was bummed, but figured this step is only done once and then the case reforms just fine after it's inaugural 300BO firing.
I must be lucky. When I still had time to make my own brass I used lee dies without issue. Of course I cut my own chambers with a PTG reamer so theoretically the dies and reamer could be bad but I don't think so.
