I keep seeing references to small base dies on other forums with claims that they size .001" to .003" smaller on the base than FL dies. Well lets see if that is true by using the following.
We will address 308 and 30.06 for this discussion but similar can be used for 223.
This is a psychological test for shooters. Remember when we were kids you had blocks and board that taught us how to put round pegs in round holes and square pegs in square holes and hexs in hex holes? Same principle here.
OK we have a new toy and obviously we like to reload to save the big bucks for more toys and buying toys that we are told are better didn't necessarily work out at least for me and small base dies are in this catagory.
First fire the rifle.
Second take the case and reorient in several positions and see if it will go back in the chamber and bolt close. If it does you don't have a egg shaped chamber which is the good news.
Third using a good micrometer measure the case .200" up from the rim. This is the standard base reference point in the ammo industry for base dimensions for ammo, chambers,reamers etc.
SAAMI Chambers for 308/30.06 will generally measure .471 to .473 and I have seen chambers that deliver .475" fired cases or FB (use your imagination on that acronym haha).
OK say you have fired cases that give worst case .473" or FB and now you are ready to size them. Screw your FL die all the way down until it <span style="text-decoration: underline">contacts the shell</span> holder and using a good case lube run the case in and then remove it.
Re mic your case at the .200" up from base point and see what you have. On 308 cases I suspect you will now have .468"-.469" New 308 cases come two ways I have seen. .465" for commercial and .468" for LC. All 30.06 new unfired I have ever miced be they commercial or LC/FA match are .465". The gov't chambers being FB were designed for bigger bases with more exposed unsupported areas in the rear (M14) thus the gov't brass is heavier, thicker as well.
OK we have a .473" fired case and a .469" sized case thusly you have a air fit condition for the base of the case and if it won't now chamber when it previously did tells us the die is the culprit because we know .469" is alot smaller than .473" right? Or in other words your sized case is now .004 smaller than the chamber which begs the question how is a "SMALL BASE" sizing the base even smaller going to help it go in?
This would suggest the FL die caused the problem but the industry tells us we need a even smaller base so they make up dies called SMALL BASE but are they really SB?
If the FL die made the case smaller at the base than the recently fired case and the bolt is hard to close shows us we now have a problem but where is it? All have read that cases get longer when they are sized and we need to trim them and we are instructed to measure the OAL of the case to determine how much they need to be trimmed. <span style="text-decoration: underline">What they always fail to mention is not only is the OAL length of the case longer, the distance from the case head to the shoulder has also become longer.</span>
Obviously thinking on it, if you trim the case length and the shoulder is not moved back to original position for semi autos or bumped .001" TO .002" for bolt guns begs the question of what have you done to achieve your goal? Nothing really. <span style="text-decoration: underline">Logically if the base to shoulder length is longer than the bolt face to shoulder length it is just not going to shut.</span>
They guy that trained me at the Army Small Cal Lab figured it out in the early 50s when he worked at Springfield Armory and had ALL THE DRAWINGS and doing a tolerance study he concluded the chamber in many of the DIES are cut too deep. What does this do? OK if the die is cut too deep it therefore follows <span style="text-decoration: underline">the die is not going to contact the shoulder of the fired case to set it back to factory length because the base of the die hit the shell holder and ramming a steel shell holder in the bottom of a steel die to size a brass case further is not going to accomplish anything if the chamber of the die is cut too deep </span>Logically we have a die fabrication problem (to deep) and not a radial dimension problem in the base requiring a SB die right? How prevalent is this (to deep) problem? Pretty bad actually. I have dies for about 52 calibers now and I have had adjust the dies so they would size correctly on over one fourth of them. I did this by chucking the dies in the lathe and cutting .010" on most and up to .025" off the bases of at least two thus making the die chamber shorter as measured from the rim to the case shoulder.
There is another tool that is very handy to have and this is a case gage. There are several but my Dad used L. E. Wilson so I got left his reloading stuff and when I needed more I ordered them made by same company. Wilson Case Gages measure several things to make sure you have a case that has been restored to factory (SAAMI) dimensions. They measure the max case diameters from neck / shoulder / body and base. Obviously if your die doesn't size enough in any of these areas the case will not go in. Assuming you have a commercial rifle made to SAAMI recommendations you can be assured if the case won't go in a L.E. Wilson case gage it is not going to go in all rifles. They may go in some rifles with headspace cut long but if you have a new barrel installed and you request min headspace (for longer case life) you are going to have problems.
The Wilson measures the distance from the head of the case to the headspace point on the shoulder. If the shoulder location has not been restored to factory length the case will sit "high" on the gage base. There are two surfaces on the base of the case gage, the lower one tells the max amount of shoulder set back you can have and be safe and the upper tells the min amount the shoulder needs to be set back in order for the bolt to close on a "0" headspace chamber. If you place a GO headspace gage in the Wilson gage it will be even with the upper surface.
Next the same gage measures the min and max OAL of the case to make sure your case neck is not jammed in end of chamber.
I have never seen a rifle that failed to chamber a case after being certified good in a Wilson Case Gage unless the OAL of the loaded is too long and the bullet is jammed in the lands. This is where good calipers come in and a Sinclair gage that looks like a big hex nut. The BIG NUT Sinclair gage allows a reloaded to set the full diameter of the bullet regardless of make to the same point in relation to the throat. You cannot rely on OAL to determine feed reliably as ogives are different for each bullet design.
OK you have a FL die that gives smaller base than fired case but won't chamber, what do you do? This is where friends come in that have a lathe. You simply remove the collar and the decap rod, chuck the die in the lathe and cut off the bottom of the die a bit. Normally I take off .010" to start with and this generally does it. I run the same case in the FL die that has been adjusted to leave a small space between die above shell holder and if I have cut enough off-- the shoulder will set back-- and the bolt closes easily (or check in Wilson Gage). I double check against the Wilson case gage and if the head of the case is even with the high shelf or between the high and low shelf I know I am good to go.
One die last year was chambered way too deep and I wound up taking off .025" inch before the case would qualify in the gage! ! ! !
Next we have those that say "if you have a tight chamber you need a SB die" because someone used a worn reamer. I run tight chambers and love them. My 30.06 reamers cut .467" and .4685" base dims. My 308 tight reamers cut .468/.4685"/469" chambers. I headspace on ZERO to boot. My chambers are so tight fired cases will go in a Wilson Case gage and spec new as I don't want anything moving over .001 to .002" on firing. This makes for long case life and with the prices of todays ammo it makes sense at least to me to do everything I can to increase case life. My chambers on my match guns can be just touched with a neck size die and go in factory chamber.
I segregate cases for all my rifles and same cases are fired in same rifle with a min of sizing. I have four sets of 30.06 dies and they size .465, .466, .468 and .470". The .470 was polished out to this dimension to size FB fired cases just enough to go back in .471-.473 chambers. My 308 dies size .467 and .469 I think it is. I do not size LC cases in the .467 die as the brass is manufactured at .468.
I do not own and never have owned a SB die. The rifles I find with FB chambers are moved on or set back and rechambered. To keep a rifle with a FB chamber just speeds up the case destruction and I moved all these out long ago.
The only time I use the .465" 30.06 die is when I have pick up brass and want to run it in a Garand. Note: The Garand clip does not like cases sized larger than .466. Anything larger makes for interesting time getting in the 8th round and thusly is so sized. So it is the clip that is the problem and not the chamber requiring sizing back to new condition.
This deep chamber problem is not restricted to one brand by any means. I have dies from I guess six or more manufacturers and as indicated about 1/4th of them had to be trimmed off the length.
I suspect the industry did not want to admit they had a production problem and thusly they came up with the SB die when in reality it is probably a die they have gaged to be "in spec" and marked as SB blaming the rifle as the problem when all along it is the die having been cut too deep.
For those of you that have never dealt with the gun industry the gun boys tend to blame all problems on the ammo boys and I have backed a couple factory reps into a corner and shut down their BS.
I have personally acceptance test fired better than a thousand rifles and I have yet to find one with a "tight chamber" as they are big and FB.
Thusly you really don't need to invest in SB dies first. You need good micrometer, caliper, case gages and be looking for a friend with a lathe. Oh yeah when you trim off bottom of die re polish the little radius on the bottom like it came from factory so the big case swells won't show a rolled up shoulder of metal from the sharp die base opening.
The moral of this little ditty, "Try before you buy". You need a good 0-1" mic, a good caliper and good case gages and whatever you do don't ever think what a factory rep says is right. I have shut down a couple factory reps when I took down their statements and called their chief engineer and told them what was said. Generally the people on the phone you talk to have orders not to give out any tech info and they know very little to start with.
For information purposes would those that already have SB marked dies please size some cases and measure them and tell us what their SMALL BASE dies resizes the base dimension to?
Also on 308/30.06 cases please measure those cases fired in a FACTORY RIFLE (not a custom rebuild) but a factory rifle and tell us the size of their fired cases.
Bottom line is do you homework before you waste money buying dies that say they are small base.
We will address 308 and 30.06 for this discussion but similar can be used for 223.
This is a psychological test for shooters. Remember when we were kids you had blocks and board that taught us how to put round pegs in round holes and square pegs in square holes and hexs in hex holes? Same principle here.
OK we have a new toy and obviously we like to reload to save the big bucks for more toys and buying toys that we are told are better didn't necessarily work out at least for me and small base dies are in this catagory.
First fire the rifle.
Second take the case and reorient in several positions and see if it will go back in the chamber and bolt close. If it does you don't have a egg shaped chamber which is the good news.
Third using a good micrometer measure the case .200" up from the rim. This is the standard base reference point in the ammo industry for base dimensions for ammo, chambers,reamers etc.
SAAMI Chambers for 308/30.06 will generally measure .471 to .473 and I have seen chambers that deliver .475" fired cases or FB (use your imagination on that acronym haha).
OK say you have fired cases that give worst case .473" or FB and now you are ready to size them. Screw your FL die all the way down until it <span style="text-decoration: underline">contacts the shell</span> holder and using a good case lube run the case in and then remove it.
Re mic your case at the .200" up from base point and see what you have. On 308 cases I suspect you will now have .468"-.469" New 308 cases come two ways I have seen. .465" for commercial and .468" for LC. All 30.06 new unfired I have ever miced be they commercial or LC/FA match are .465". The gov't chambers being FB were designed for bigger bases with more exposed unsupported areas in the rear (M14) thus the gov't brass is heavier, thicker as well.
OK we have a .473" fired case and a .469" sized case thusly you have a air fit condition for the base of the case and if it won't now chamber when it previously did tells us the die is the culprit because we know .469" is alot smaller than .473" right? Or in other words your sized case is now .004 smaller than the chamber which begs the question how is a "SMALL BASE" sizing the base even smaller going to help it go in?
This would suggest the FL die caused the problem but the industry tells us we need a even smaller base so they make up dies called SMALL BASE but are they really SB?
If the FL die made the case smaller at the base than the recently fired case and the bolt is hard to close shows us we now have a problem but where is it? All have read that cases get longer when they are sized and we need to trim them and we are instructed to measure the OAL of the case to determine how much they need to be trimmed. <span style="text-decoration: underline">What they always fail to mention is not only is the OAL length of the case longer, the distance from the case head to the shoulder has also become longer.</span>
Obviously thinking on it, if you trim the case length and the shoulder is not moved back to original position for semi autos or bumped .001" TO .002" for bolt guns begs the question of what have you done to achieve your goal? Nothing really. <span style="text-decoration: underline">Logically if the base to shoulder length is longer than the bolt face to shoulder length it is just not going to shut.</span>
They guy that trained me at the Army Small Cal Lab figured it out in the early 50s when he worked at Springfield Armory and had ALL THE DRAWINGS and doing a tolerance study he concluded the chamber in many of the DIES are cut too deep. What does this do? OK if the die is cut too deep it therefore follows <span style="text-decoration: underline">the die is not going to contact the shoulder of the fired case to set it back to factory length because the base of the die hit the shell holder and ramming a steel shell holder in the bottom of a steel die to size a brass case further is not going to accomplish anything if the chamber of the die is cut too deep </span>Logically we have a die fabrication problem (to deep) and not a radial dimension problem in the base requiring a SB die right? How prevalent is this (to deep) problem? Pretty bad actually. I have dies for about 52 calibers now and I have had adjust the dies so they would size correctly on over one fourth of them. I did this by chucking the dies in the lathe and cutting .010" on most and up to .025" off the bases of at least two thus making the die chamber shorter as measured from the rim to the case shoulder.
There is another tool that is very handy to have and this is a case gage. There are several but my Dad used L. E. Wilson so I got left his reloading stuff and when I needed more I ordered them made by same company. Wilson Case Gages measure several things to make sure you have a case that has been restored to factory (SAAMI) dimensions. They measure the max case diameters from neck / shoulder / body and base. Obviously if your die doesn't size enough in any of these areas the case will not go in. Assuming you have a commercial rifle made to SAAMI recommendations you can be assured if the case won't go in a L.E. Wilson case gage it is not going to go in all rifles. They may go in some rifles with headspace cut long but if you have a new barrel installed and you request min headspace (for longer case life) you are going to have problems.
The Wilson measures the distance from the head of the case to the headspace point on the shoulder. If the shoulder location has not been restored to factory length the case will sit "high" on the gage base. There are two surfaces on the base of the case gage, the lower one tells the max amount of shoulder set back you can have and be safe and the upper tells the min amount the shoulder needs to be set back in order for the bolt to close on a "0" headspace chamber. If you place a GO headspace gage in the Wilson gage it will be even with the upper surface.
Next the same gage measures the min and max OAL of the case to make sure your case neck is not jammed in end of chamber.
I have never seen a rifle that failed to chamber a case after being certified good in a Wilson Case Gage unless the OAL of the loaded is too long and the bullet is jammed in the lands. This is where good calipers come in and a Sinclair gage that looks like a big hex nut. The BIG NUT Sinclair gage allows a reloaded to set the full diameter of the bullet regardless of make to the same point in relation to the throat. You cannot rely on OAL to determine feed reliably as ogives are different for each bullet design.
OK you have a FL die that gives smaller base than fired case but won't chamber, what do you do? This is where friends come in that have a lathe. You simply remove the collar and the decap rod, chuck the die in the lathe and cut off the bottom of the die a bit. Normally I take off .010" to start with and this generally does it. I run the same case in the FL die that has been adjusted to leave a small space between die above shell holder and if I have cut enough off-- the shoulder will set back-- and the bolt closes easily (or check in Wilson Gage). I double check against the Wilson case gage and if the head of the case is even with the high shelf or between the high and low shelf I know I am good to go.
One die last year was chambered way too deep and I wound up taking off .025" inch before the case would qualify in the gage! ! ! !
Next we have those that say "if you have a tight chamber you need a SB die" because someone used a worn reamer. I run tight chambers and love them. My 30.06 reamers cut .467" and .4685" base dims. My 308 tight reamers cut .468/.4685"/469" chambers. I headspace on ZERO to boot. My chambers are so tight fired cases will go in a Wilson Case gage and spec new as I don't want anything moving over .001 to .002" on firing. This makes for long case life and with the prices of todays ammo it makes sense at least to me to do everything I can to increase case life. My chambers on my match guns can be just touched with a neck size die and go in factory chamber.
I segregate cases for all my rifles and same cases are fired in same rifle with a min of sizing. I have four sets of 30.06 dies and they size .465, .466, .468 and .470". The .470 was polished out to this dimension to size FB fired cases just enough to go back in .471-.473 chambers. My 308 dies size .467 and .469 I think it is. I do not size LC cases in the .467 die as the brass is manufactured at .468.
I do not own and never have owned a SB die. The rifles I find with FB chambers are moved on or set back and rechambered. To keep a rifle with a FB chamber just speeds up the case destruction and I moved all these out long ago.
The only time I use the .465" 30.06 die is when I have pick up brass and want to run it in a Garand. Note: The Garand clip does not like cases sized larger than .466. Anything larger makes for interesting time getting in the 8th round and thusly is so sized. So it is the clip that is the problem and not the chamber requiring sizing back to new condition.
This deep chamber problem is not restricted to one brand by any means. I have dies from I guess six or more manufacturers and as indicated about 1/4th of them had to be trimmed off the length.
I suspect the industry did not want to admit they had a production problem and thusly they came up with the SB die when in reality it is probably a die they have gaged to be "in spec" and marked as SB blaming the rifle as the problem when all along it is the die having been cut too deep.
For those of you that have never dealt with the gun industry the gun boys tend to blame all problems on the ammo boys and I have backed a couple factory reps into a corner and shut down their BS.
I have personally acceptance test fired better than a thousand rifles and I have yet to find one with a "tight chamber" as they are big and FB.
Thusly you really don't need to invest in SB dies first. You need good micrometer, caliper, case gages and be looking for a friend with a lathe. Oh yeah when you trim off bottom of die re polish the little radius on the bottom like it came from factory so the big case swells won't show a rolled up shoulder of metal from the sharp die base opening.
The moral of this little ditty, "Try before you buy". You need a good 0-1" mic, a good caliper and good case gages and whatever you do don't ever think what a factory rep says is right. I have shut down a couple factory reps when I took down their statements and called their chief engineer and told them what was said. Generally the people on the phone you talk to have orders not to give out any tech info and they know very little to start with.
For information purposes would those that already have SB marked dies please size some cases and measure them and tell us what their SMALL BASE dies resizes the base dimension to?
Also on 308/30.06 cases please measure those cases fired in a FACTORY RIFLE (not a custom rebuild) but a factory rifle and tell us the size of their fired cases.
Bottom line is do you homework before you waste money buying dies that say they are small base.
