Reloading dies for an AR ?
- Thread starter Hal
- Start date
bigedp51
Military type 5.56 chambers are .002 or more larger in diameter than civilian commercial .223 chambers, therefore a standard full length .223 resizing die will work just fine.
If the AR has a commercial or custom .223 chamber that is tighter you may need a small base die. If you reload once fired 5.56 military ammunition that was fired in a M240 machine gun with a even bigger chamber small base dies are used once on this brass and then normal FL dies are used.
Nothing is written is stone and not all chamber are mil-spec, I would start with standard .223 FL length dies and if you have chambering problems then get a small base die. In 46 years of reloading I have never needed small base dies, BUT I have a .223 small base die just in case. I'm also loading for three ARs and use nothing but standard dies. I ran tests on once fired Remington .223 brass fired in a AR, the small base die only made the base diameter .0005 smaller in diameter compared to a standard FL .223 die.
Below, the 5.56 (C) base diameter is .002 larger on the AR type rifles then the .223 and a standard die will make the base diameter small enough.
Below, the 7.62 chamber is .0025 larger in diameter than the .308 and a FL .308 die will make the base diameter small enough.
If the AR has a commercial or custom .223 chamber that is tighter you may need a small base die. If you reload once fired 5.56 military ammunition that was fired in a M240 machine gun with a even bigger chamber small base dies are used once on this brass and then normal FL dies are used.
Nothing is written is stone and not all chamber are mil-spec, I would start with standard .223 FL length dies and if you have chambering problems then get a small base die. In 46 years of reloading I have never needed small base dies, BUT I have a .223 small base die just in case. I'm also loading for three ARs and use nothing but standard dies. I ran tests on once fired Remington .223 brass fired in a AR, the small base die only made the base diameter .0005 smaller in diameter compared to a standard FL .223 die.
Below, the 5.56 (C) base diameter is .002 larger on the AR type rifles then the .223 and a standard die will make the base diameter small enough.
Below, the 7.62 chamber is .0025 larger in diameter than the .308 and a FL .308 die will make the base diameter small enough.
Thanks for the info.
Years ago I reloaded for a .243 in a Savage 99 , it required a small base die or the lever closed hard.
I also reloaded some .220 swift shells for a kids early Ruger 77. If you tried to chamber a factory once fired reloaded case, that had been sized with a RCBS die the bolt would not cam over. I bought a set of Lee dies, because I had heard they had a smaller base inside diameter.
When sized to the max, the bolt would just close snugly.
I'm sure it was an over sized chamber on that rifle.
Hal
Years ago I reloaded for a .243 in a Savage 99 , it required a small base die or the lever closed hard.
I also reloaded some .220 swift shells for a kids early Ruger 77. If you tried to chamber a factory once fired reloaded case, that had been sized with a RCBS die the bolt would not cam over. I bought a set of Lee dies, because I had heard they had a smaller base inside diameter.
When sized to the max, the bolt would just close snugly.
I'm sure it was an over sized chamber on that rifle.
Hal
bigedp51
Just a little followup, I would not be afraid to use a small base die in a semi-auto, "BUT" remember the military chamber is fatter and "LONGER" than SAAMI civilian standards. Meaning you can very easily over resize your cases and bump/push the shoulder back too far and cause case head seperations.
The chamber headspace length will be longer on the majority of 5.56 and 7.62 chambers. I would get the Hornady cartridge case headspace gauge and make sure you do NOT bump the shoulder back too far. On a semi .002 to .004 shoulder bump is more than enough.
Below the Hornady case gauge which works better than Wilson type case gauges.
Below, a Remington .223 case fired in a AR15 military chamber, this case is too large in diameter to fit in the Wilson gauge, and the Hornady gauge doesn't care how fat the case gets.
And for my buddy here who prefers Wilson case gauges pictured below is one of my new Wilson pen holders. :
The chamber headspace length will be longer on the majority of 5.56 and 7.62 chambers. I would get the Hornady cartridge case headspace gauge and make sure you do NOT bump the shoulder back too far. On a semi .002 to .004 shoulder bump is more than enough.
Below the Hornady case gauge which works better than Wilson type case gauges.
Below, a Remington .223 case fired in a AR15 military chamber, this case is too large in diameter to fit in the Wilson gauge, and the Hornady gauge doesn't care how fat the case gets.
And for my buddy here who prefers Wilson case gauges pictured below is one of my new Wilson pen holders. :
Good info Bigedp51! The dimensions comparison are really nice to see. I did just order the Wilson gauge for my AR even though I have the equivalent Sinclair tool to the Hornady one you illustrated. I got the Wilson because my AR is chambered in 223 Remington, not 5.56, and could use it as a double check to make sure the case will chamber reliably. I am new at this stuff! I also got it, well, because, I like tools. I also agree the small base die should not be needed.
Phil
I also agree the small base die should not be needed. Phil
bigedp51
Nothing wrong with a Wilson case gauge, BUT there is a difference between commercial .223 cases and military Lake City cases. I do not have a problem with .223 cases fitting the Wilson gauge when fired in my .223 bolt action with a smaller diameter chamber.
Also note that the SAAMI interchangeability warning for the .223 and 5.56 did not come out until 1979 when the new and hotter M855 ammunition came on line. The older M193 ammunition is loaded to the same pressures as .223 ammo.
The first commercial contract M16 ammunition was part of the early jamming problem with the M16 rifle and the military set new hardness requirements for contract military ammunition.
Also note that the SAAMI interchangeability warning for the .223 and 5.56 did not come out until 1979 when the new and hotter M855 ammunition came on line. The older M193 ammunition is loaded to the same pressures as .223 ammo.
The first commercial contract M16 ammunition was part of the early jamming problem with the M16 rifle and the military set new hardness requirements for contract military ammunition.
I don't use military cases. For the AR, I am buying 223 cases from Winchester. I am a little perplexed by "I do not have a problem with .223 cases fitting the Wilson gauge when fired in my .223 bolt action with a smaller diameter chamber". My understand is that the Wilson is to ensure that resized brass will chamber reliably. Given this is an AR, I don't want jams and figured the gauge is a simple go/no-go approach to ensuring resized brass will chamber reliably. Even though my AR is chambered in 223 (NOT 5.56), I never expected the fired case to fit the Wilson. Am I off track here?
Phil
Phil
Phil3 said:
Phil,
I have used all kinds of 223 brass. But I am right now sold on LC brass. Got rid of my Lapua brass and for now, I don't think that I will be buying any of it any time soon.
bigedp51
Phil3 said:
The Wilson gauge allows the case to rest on the shoulder and you "gauge" the case between the high and low reference marks. The fired case must fit in the Wilson gauge to see how long the case is after it is fired. Then you decide how to adjust the resizing die for the correct shoulder bump. Meaning how much "shorter" are you going to make the fired case. Therefore you need a "before and after" to "gauge" your sizing operation.
The Wilson case gauge is a commercial SAAMI gauge and your firing .223 cases in a longer and fatter military chamber that is NOT a SAAMI commercial dimension chamber. My .223 cases fired in my AR expand outward more (too fat) and do not fit the gauge until they are resized.
Normally a case fired in a .223 commercial SAAMI chamber will fit a Wilson gauge after firing. Two things were going on, the .223 cases were loaded to higher military chamber pressures and then fired in a larger diameter military chamber and they became a smidgen larger in diameter than "normal" to fit a Wilson gauge.
If I wanted to I could make the Wilson gauge larger on the inside near the base of the case and make these cases fit the gauge. BUT the Hornady gauge is easier to use with chronological gifted eyesight.
If you buy the Hornady case gauge you will only need to buy "ONE" gauge, if you buy Wilson gauges you will need to buy a gauge for every caliber cartridge.
Below is the most extreme difference between a civilian chamber and a military chamber you will ever see.
Below a Wilson gauge with a new .303 British case in the gauge, Remington doesn't know where to put the shoulder of the case and it is a 1/4 inch too short.
Below is a .303 British case fired in a military Enfield rifle, the amount the case is sticking above the gauge is how much longer the military chamber is from American SAAMI dimensions.
(it all started 237 years ago when we had the disagreement with King George) :
Bottom line, sometimes Mr. Wilson tells a lie with military chambers.
bigedp51 said:
I'm not firing 223 cases in a longer and fatter military chamber. The chamber in the barrel I bought from Krieger was specifically chambered in 223 and NOT a military chambering. According to Krieger (to the best of my recollection), the chamber is to minimum SAAMI specs. I have a call into Krieger to confirm the reamer used.
I looked at the Hornady case gauge, and if we are talking about the same thing, the tool is device that clips on the caliper blade with caliber specific inserts. If so, I already have the same thing from Sinclair. I opted for the Wilson case gauge to mostly confirm my own should setback using the Sinclair tool and to see how far out from SAAMI specs the fired cartridge might be.
Phil
Phil,
Both of my .223's have a Wylde chamber in them and throated for the 90's. I have not had any problems with the LC brass.
Both of my .223's have a Wylde chamber in them and throated for the 90's. I have not had any problems with the LC brass.
bigedp51
Phil3 said:
You asked this question.
Phil3 said:
I fired a "softer" commercial case in my 5.56 chamber and it was too "fat" to fit in a Wilson case gauge after it was fired. "NORMALLY" a fired case will fit in a Wilson case gauge "IF" fired in a SAAMI chamber. What I should have added before was my fired Lake City cases fit in the Wilson case gauge because military brass is harder in the base to withstand higher pressures and larger diameter chambers.
"YOU" asked a question, and I gave an answer of "WHY" the case fired in "MY" military chamber did not fit in "MY" Wilson gauge. YOU stated you never expected a fired case to fit the Wilson gauge. If you don't measure a fired case how will you know how much shorter to make the resized case? The Wilson gauge is a before and after resizing comparator gauge.
What fits in your chamber and Wilson gauge will be up to you, loading commercial cases to the AR 15s higher pressures "might" cause problems. You might need small base dies with your Winchester cases to fit your smaller than normal Krieger chamber. (it could be .0025 smaller in diameter)
Also if your AR is over gassed and most are, when the bolt starts moving to the rear there is still pressure in the barrel. This pressure as the bolt moves to the rear can cause the shoulder of the case to move forward. Meaning your fired cases might be longer than your chamber and you will get a false reading of fired case length in the Wilson gauge. This might cause you to not bump the shoulder back far enough and cause chambering problems.
You need to know how long your chamber is to the shoulder datum point to resize your fired cases "SMALLER" than your chamber. Normally you measure a fired case so you will know how much shorter to make the resized case so it will chamber reliably.
bigedp51
How a cheap bastard checks how long his chamber really is and not be fooled by a over gassed AR15, M1A or M1 Garand.
1. On a new or full length resized case and using your fingers start a fired spent primer into the primer pocket.
2. Slowly chamber this test round and allow the bolt to seat the primer.
The amount the primer is protruding is your head clearance or the "air space" between the rear of the case and the bolt face. If measured using a Hornady type cartridge case headspace gauge this test case will give you your chamber length, datum line to rear of primer. Knowing this will allow you to bump your case shoulder the proper amount.
Example below of excess headspace.
(remember its the "air space" that screws up your cases and puts unwanted foam on your upper lip) :
1. On a new or full length resized case and using your fingers start a fired spent primer into the primer pocket.
2. Slowly chamber this test round and allow the bolt to seat the primer.
The amount the primer is protruding is your head clearance or the "air space" between the rear of the case and the bolt face. If measured using a Hornady type cartridge case headspace gauge this test case will give you your chamber length, datum line to rear of primer. Knowing this will allow you to bump your case shoulder the proper amount.
Example below of excess headspace.
(remember its the "air space" that screws up your cases and puts unwanted foam on your upper lip) :
Not to hijack this thread, but I have a couple comments and questions. I shoot primarily 6.5 Grendel based AR's...love the round...not a big fan of 223 so hopefully this isn't inappropriate in this post.
So I purchased the Hornady comparator initially when I began reloading. The Hornady, as I understand it, does not give an exact measure of a case length. It measures from the base to datum. It also is highly dependent on the insert used. So it is great for comparing resized vs fireformed brass but, as I understand it--and correct me if I'm wrong, I didn't think it was capable of a direct measurement to confirm SAAMI specs.
Now the Sinclair...as I understand it...measures shoulder to base. So I assume that you could probably measure the true length of the case and compare to SAAMI.
I have Wilson chamber gages for all calibers I reload. I usually reload my rounds to my chamber and not the gage. So, for example, when I resize my Grendel cases, the bases will fail the Wilson gage by a couple thousandths, but the case fits my chamber. However, the Wilson will still give a quick indication of whether a case has been appropriately sized because the amount of protrusion is easily to observe visually and if any gross variance the I will disposition the case to a measurement with the calipers.
Now to the issue of shoulder setback for an AR...The amount of shoulder setback after fireforming, in a high pressure round like the Grendel, makes reloading very interesting. The overgassed nature of the round can really mess up cases. I had a rifle that created belted magnums out of Lapua brass due to overgassing and early unlocking. An adjustable gas block solved this issue.
However, I have noted that on fired brass, that to get a non-interference fit out of my resized brass, that I have to push the shoulder back 0.006". I can bump shoulders back 0.003" and have them chamber (after allowing the bolt carrier to slam them home from a locked position). However, after a measurement with the comparator, I find that the shoulder becomes setback an additional 0.003". I set back 50 cases 0.006" and they chamber without any further setback from the bolt. I know that 0.006" of setback may set me up for headspace problems and case head separations, but I can't get reliable chambering if I don't set them back that far. So my HIJACK question to this thread is whether the more seasoned AR reloaders would recommend continuing to resize brass to the 0.006" setback or to stop at 0.003" and allow the bolt to crush the case down further...risking occasional stuck cases. It should be noted that even after a 0.006" setback, the cases are still proud of the Wilson gage.
bigedp51...couple questions.
1. Does the ejector need removed from the bolt to measure?
2. How do you measure the head clearance? If you measure with calipers, as soon as you touch the primer wouldn't the pressure from the jaws push it in and change your measurement at least a thousandth or two?
So I purchased the Hornady comparator initially when I began reloading. The Hornady, as I understand it, does not give an exact measure of a case length. It measures from the base to datum. It also is highly dependent on the insert used. So it is great for comparing resized vs fireformed brass but, as I understand it--and correct me if I'm wrong, I didn't think it was capable of a direct measurement to confirm SAAMI specs.
Now the Sinclair...as I understand it...measures shoulder to base. So I assume that you could probably measure the true length of the case and compare to SAAMI.
I have Wilson chamber gages for all calibers I reload. I usually reload my rounds to my chamber and not the gage. So, for example, when I resize my Grendel cases, the bases will fail the Wilson gage by a couple thousandths, but the case fits my chamber. However, the Wilson will still give a quick indication of whether a case has been appropriately sized because the amount of protrusion is easily to observe visually and if any gross variance the I will disposition the case to a measurement with the calipers.
Now to the issue of shoulder setback for an AR...The amount of shoulder setback after fireforming, in a high pressure round like the Grendel, makes reloading very interesting. The overgassed nature of the round can really mess up cases. I had a rifle that created belted magnums out of Lapua brass due to overgassing and early unlocking. An adjustable gas block solved this issue.
However, I have noted that on fired brass, that to get a non-interference fit out of my resized brass, that I have to push the shoulder back 0.006". I can bump shoulders back 0.003" and have them chamber (after allowing the bolt carrier to slam them home from a locked position). However, after a measurement with the comparator, I find that the shoulder becomes setback an additional 0.003". I set back 50 cases 0.006" and they chamber without any further setback from the bolt. I know that 0.006" of setback may set me up for headspace problems and case head separations, but I can't get reliable chambering if I don't set them back that far. So my HIJACK question to this thread is whether the more seasoned AR reloaders would recommend continuing to resize brass to the 0.006" setback or to stop at 0.003" and allow the bolt to crush the case down further...risking occasional stuck cases. It should be noted that even after a 0.006" setback, the cases are still proud of the Wilson gage.
bigedp51...couple questions.
1. Does the ejector need removed from the bolt to measure?
2. How do you measure the head clearance? If you measure with calipers, as soon as you touch the primer wouldn't the pressure from the jaws push it in and change your measurement at least a thousandth or two?
bigedp51
bronco_buster said:
1. I have done it both ways and it is a bit easier with the extractor removed, but is not necessary. Use which ever method gives you the most consistent readings.
2. As long as you do not have a loose primer pocket a good bit of force is required to move the primer.
3. Use the primer method to find your chamber length and get a accurate reading for the proper shoulder setback and then don't guess if your shoulder bump is .003 or .006.
bigedp51 said:Phil3 said:
You asked this question.
Phil3 said:
I fired a "softer" commercial case in my 5.56 chamber and it was too "fat" to fit in a Wilson case gauge after it was fired. "NORMALLY" a fired case will fit in a Wilson case gauge "IF" fired in a SAAMI chamber. What I should have added before was my fired Lake City cases fit in the Wilson case gauge because military brass is harder in the base to withstand higher pressures and larger diameter chambers.
"YOU" asked a question, and I gave an answer of "WHY" the case fired in "MY" military chamber did not fit in "MY" Wilson gauge. YOU stated you never expected a fired case to fit the Wilson gauge. If you don't measure a fired case how will you know how much shorter to make the resized case? The Wilson gauge is a before and after resizing comparator gauge.
What fits in your chamber and Wilson gauge will be up to you, loading commercial cases to the AR 15s higher pressures "might" cause problems. You might need small base dies with your Winchester cases to fit your smaller than normal Krieger chamber. (it could be .0025 smaller in diameter)
Also if your AR is over gassed and most are, when the bolt starts moving to the rear there is still pressure in the barrel. This pressure as the bolt moves to the rear can cause the shoulder of the case to move forward. Meaning your fired cases might be longer than your chamber and you will get a false reading of fired case length in the Wilson gauge. This might cause you to not bump the shoulder back far enough and cause chambering problems.
You need to know how long your chamber is to the shoulder datum point to resize your fired cases "SMALLER" than your chamber. Normally you measure a fired case so you will know how much shorter to make the resized case so it will chamber reliably.
I think we are going around in circles, but think I have all that I need to know. If I have something wrong, please let me know.
"..."NORMALLY" a fired case will fit in a Wilson case gauge "IF" fired in a SAAMI chamber...".Yes, I know this. And my chamber IS a SAAMI 223 chamber. I watched this Wilson video and that is clear.
http://www.youtube.com/watch?v=RuJYpm-qplQ
"...If you don't measure a fired case how will you know how much shorter to make the resized case? The Wilson gauge is a before and after resizing comparator gauge..."
I know the Wilson is a comparator. As stated earlier, I wanted to use the gauge to see if the resized cases fall within SAAMI specs, and to validate that my own measurements (calipers) are generally correct. If my chamber is SAAMI spec (which I believe it is), then the fired case and resized cases should fit the Wilson and can make use of the tool. If the chamber is NOT SAAMI spec, then the fired case may not fit and the Wilson is returned. We'll see.
"...What fits in your chamber and Wilson gauge will be up to you, loading commercial cases to the AR 15s higher pressures "might" cause problems. You might need small base dies with your Winchester cases to fit your smaller than normal Krieger chamber. (it could be .0025 smaller in diameter)...".
After sizing, will see how the chambering goes. I'll try to remember to ask Krieger if they think small base dies are needed for the reamer they used. I had not thought of that possible necessity.
"...Also if your AR is over gassed and most are, when the bolt starts moving to the rear there is still pressure in the barrel. This pressure as the bolt moves to the rear can cause the shoulder of the case to move forward. Meaning your fired cases might be longer than your chamber and you will get a false reading of fired case length in the Wilson gauge. This might cause you to not bump the shoulder back far enough and cause chambering problems...".
Yup. I will be measuring exact chamber length in the gun once I get around to taking the bolt apart. I tried your primer process but with extractor and ejector in (too little time to take apart), and as I recall, the distance from primer to shoulder was no different than a fired case from case head to shoulder. It does not appear the case is getting stretched while the bolt is unlocking. It is possible the rifle is over gassed, but really don't know how to tell. The gun uses a rifle length gas system, a 22" barrel (which prolongs gas pressure vs a shorter rifle length barrel), but does use a slightly heavier bolt carrier assembly (Young Manufacturing Match). I intend on doing the primer test again without the ejector and maybe the extractor.
You need to know how long your chamber is to the shoulder datum point to resize your fired cases "SMALLER" than your chamber. Normally you measure a fired case so you will know how much shorter to make the resized case so it will chamber reliably.
Yes, and have been doing that with the Sinclair tool. I have my die set up to give about .003 - .004 shoulder bump. I will be interested to see where that sized case fits in the Wilson. Above the high mark, below the lowest mark, or? If in the range, it can act as a quick check to make sure cases are where they need to be. If outside the min and max levels, the calipers will be faster.
Phil
bigedp51
If you over resize your .223 cases meaning bump the shoulder back too far in your AR15 short case life isn't the only problem you will have. The military crimps their primers for a reason.
The AR bolt is moving to the rear powered by gas pressure which is still in the barrel as the bolt is moving. Below the anvil acted like a cork and sealed the hole in the punctured primer.
Below is an example, you pull the trigger and the firing pin drives the case forward until it contacts the shoulder of the chamber. The case goes bang and the chamber pressure forces the primer to the rear until it contacts the bolt face. This action on a uncrimped primer can allow the firing pin to punch the center out of the primer hit. Excess headspace or excess cartridge headspace will create excess head clearance increasing the fired primers movement to the rear. (along with a bolt thats moving to the rear with pressure in the bore)
The AR bolt is moving to the rear powered by gas pressure which is still in the barrel as the bolt is moving. Below the anvil acted like a cork and sealed the hole in the punctured primer.
Below is an example, you pull the trigger and the firing pin drives the case forward until it contacts the shoulder of the chamber. The case goes bang and the chamber pressure forces the primer to the rear until it contacts the bolt face. This action on a uncrimped primer can allow the firing pin to punch the center out of the primer hit. Excess headspace or excess cartridge headspace will create excess head clearance increasing the fired primers movement to the rear. (along with a bolt thats moving to the rear with pressure in the bore)
I'm well aware of the issues excessive headspace can cause. It is why I have the tools to guard against it. The described process of what happens in the chamber would appear to be applicable to any rifle (other than the bolt moving rearward). Since many cartridges do not have crimped primers, I assume they function fine because headspace is minimal and limits primer rearward movement.
I have read this several times a ways back and thought you might find it interesting.
http://www.ar15barrels.com/prod/operation.shtml
Phil
I have read this several times a ways back and thought you might find it interesting.
http://www.ar15barrels.com/prod/operation.shtml
Phil
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