.223vs 5.56mm

cdoc42 · June 16, 2020, 04:41 PM

I have a .223 AR-15 and when I resize my fired cases, any that need to be trimmed come off the Lyman electric trimmer without a problem.

My neighbor has a ".223" but when I resize his cases and try to trim them, I cannot pull them off the pilot without stopping the unit and using a screwdriver against the pilot holder to prevent the whole works from coming out the the trimmer. The only way I can successfully trim them is to partially trim, then deburr in and out of the case mouth, then trim again.

If he really has a 5.56mm and not a .223, might that be the problem? If not, what is?

Shadow9mm · June 16, 2020, 05:58 PM

I'm guessing its a trimmer or a die problem, not a brass problem. Your die should resize the brass identically, but more importantly expand the internal neck diameter to the same size with any brass. If it is getting stuck on the pilot either your pilot is messed up or the expander ball in your die is under sized.

cdoc42 · June 16, 2020, 06:46 PM

I understand how this can be a problem if the cutter is too worn, but it should occur with ALL .223 cases. The same is true if the pilot or expander ball is the problem. But why would it work well with my .223 and not another?

Shadow9mm · June 16, 2020, 09:35 PM

resize some of his brass and yours, measure the inside of the neck, neck thickness and outside of neck, see if there are any differences. One other though, yout trimmer head might be dull, causing a burr on the inside of the case mouth making it grab the pilot. if his brass is longer and you are taking off more metal this might be the problem.

big al hunter · June 16, 2020, 10:37 PM

Is his brass the same head stamp? Different makers have different hardness of brass. That plus a little extra length to trim could make the burr on the inside of the neck larger. Measure the length of the resized brass for both rifles prior to trimming as well.

Also try trimming his brass in smaller increments. Work it back and forth a few times until you hit the stop. The burr on the inside will be pushed back to the cutter as you work it.

Metal god · June 17, 2020, 12:28 PM

Its that you are cutting to much off the mouth at once , meaning when the cases are sized they are growing in length longer then normal . I get this with once fired NATO brass . The burrs and cuttings build up at the case mouth jamming the pilot up . This does not happen if I’m only trimming a few thousandths . If the case is supported enough try to trim with out the pilot . That’s what I have to do with my Lyman universal case trimmer .

If I'm right the insides of the case mouths have smear marks from the cuttings rubbing between the pilot and inside of the case mouth .

This is what mine looked like , note the shiny inside top edge .

cdoc42 · June 17, 2020, 09:04 PM

Shadow9mm, his brass may be longer, but would this occur if he had a 5.56mm rifle and not a .223? When I check to see what has to be trimmed,I just set the caliper at recommended max length and anything that doesn't fit gets trimmed. I have not measured how far over max his cases may be. I will have to do that.

big al hunter, I was trimming in steps to overcome this, and at various increments I went so far to champfer and deburr, then continue to trim to the stop. But that is taking all the fun out of handloading these .223s.

metalgod, thanks for the photos. I will check these cases to see if they look like the ones you posted. I hesitate to trim without a pilot as the unsupported case seems to whip around too much. Unfortunately the only smaller pilot I have is .17 caliber and that leaves a lot of wiggle room as well.

This neighbor wants to get into reloading so this is a good lesson for him as well. He will do all the work with my equipment under my supervision right now, and when he feels accomplished, he'll invest and load on his own. Maybe I'll advise him to keep his .223s aside and use my inventory as I have a few thousand cases.

But back to the difference between a 5.56mm and .223. Would his fired cases be longer if he really has a 5.56mm and not a .223?

Metal god · June 17, 2020, 09:59 PM

Quote:

metalgod, thanks for the photos. I will check these cases to see if they look like the ones you posted. I hesitate to trim without a pilot as the unsupported case seems to whip around too much. Unfortunately the only smaller pilot I have is .17 caliber and that leaves a lot of wiggle room as well.

I understand , I'm 99.99% convinced what I said is your problem .

Quote:

But back to the difference between a 5.56mm and .223. Would his fired cases be longer if he really has a 5.56mm and not a .223?

Short answer no , long answer maybe . Remember when you size a case it does not compress down equally in all directions . As you size the case smaller the die is actually forcing brass to move in the direction of least resistance . That is towards the case neck resulting in the case getting longer . The farther you size it down the longer the neck will get . If it's a very loose chamber the cases "could" be abnormally large after firing and again when you size them back down the brass is extruded to and through the shoulder and neck making it longer when your done . This results in you needing to trim more then normal . This is very common when sizing NATO 308 brass that has been fired from a machinegun because they have very generous chambers bloating out the cases when fired .

Unless this is a new trimmer and there's something wrong , I'm assuming you've used the trimmer many times and this is the first time this issue has come up ? You are just needing top trim more then what is typical . I was needing to trim so much off of my LC 308 cases the pilot would not come out . I had to push the pilot into the case , chamfer and deburr then get the pilot out .

There is another thing that comes to mind . Maybe who ever sized the cases is using an undersized expander button which would result in the inside diameter of the necks to be smaller leaving less room for the pilot .

cdoc42 · June 18, 2020, 01:34 PM

Thanks, metal god. This is not the first time I've had this problem, and the last time it was corrected by replacing the trimmer cutter. I did that again, to no avail.

I resized both his and my cases in the same die, and my cases had no problem with the pilot - only his. So I think it makes sense that maybe his chamber is larger and the cases get longer when sized. I'll measure a bunch pre- and post-sizing and compare them to the measurements on my cases.

rsnell · June 18, 2020, 02:23 PM

I believe Metal God has the correct answer. 0.223 inches is the diameter of the projectile and has nothing to do with the length. In addition, 0.223" converted to mm is 5.6642 mm.

cdoc42 · June 19, 2020, 02:41 PM

" 0.223 inches is the diameter of the projectile and has nothing to do with the length. In addition, 0.223" converted to mm is 5.6642 mm."

The issue was not the diameter of the bullet, but the length of the case. The 5.56 NAto throat is 0.125" longer than the .223 rifle. The question was if a standard .223 case is fired in a 5.56 NAto rifle, will the case expand to a longer length, and if I trim it to a conventinal .223 length will the excess brass cause the pilot to bind when trimming.

Even more confusing, however, is trying convert bullet diameters from inches to mm. It s true that .223" = 5.6642mm, but the Nato chamber is listed as 5.56mm, which is really 0.219".

Worse, both the .223 and 5.56 fire a .224" bullet which is 5.69mm

The difference between any two may be the diameter of the lands versus the grooves.

Look at 30 caliber bullets; they are .308" in diameter which is 7.82mm, yet the 30 caliber rifles are labeled 7.62mm, which is really equal to 0.300"

Metal god · June 19, 2020, 08:03 PM

The throat is not the part of the chamber that involves case length . The trim to length and max case length are the same for both 223 and 5.56 . A way to understand that 223 and 5.56 case Dimensions are the same is understanding that they don’t make 5.56 dies you just use a 223 dies for both .

There’s no statistical difference between the brass and what you size it to between 223 and 5.56 . This is not your problem your problem it’s not that one rifle is a 556 and the other is a 223 . If anything your problem is one rifle has a chamber that is very generous but still within the specs of 223 .i

cdoc42 · June 20, 2020, 10:04 AM

" If anything your problem is one rifle has a chamber that is very generous but still within the specs of 223"

Got it! That makes sense.

June 16, 2020, 04:41 PM	#1
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	.223vs 5.56mm I have a .223 AR-15 and when I resize my fired cases, any that need to be trimmed come off the Lyman electric trimmer without a problem. My neighbor has a ".223" but when I resize his cases and try to trim them, I cannot pull them off the pilot without stopping the unit and using a screwdriver against the pilot holder to prevent the whole works from coming out the the trimmer. The only way I can successfully trim them is to partially trim, then deburr in and out of the case mouth, then trim again. If he really has a 5.56mm and not a .223, might that be the problem? If not, what is?

June 16, 2020, 05:58 PM	#2
Shadow9mm Senior Member Join Date: March 21, 2012 Location: Indianapolis, IN Posts: 3,969	I'm guessing its a trimmer or a die problem, not a brass problem. Your die should resize the brass identically, but more importantly expand the internal neck diameter to the same size with any brass. If it is getting stuck on the pilot either your pilot is messed up or the expander ball in your die is under sized. Last edited by Shadow9mm; June 16, 2020 at 06:03 PM.

June 16, 2020, 10:37 PM	#5
big al hunter Senior Member Join Date: March 12, 2011 Location: Washington state Posts: 1,558	Is his brass the same head stamp? Different makers have different hardness of brass. That plus a little extra length to trim could make the burr on the inside of the neck larger. Measure the length of the resized brass for both rifles prior to trimming as well. Also try trimming his brass in smaller increments. Work it back and forth a few times until you hit the stop. The burr on the inside will be pushed back to the cutter as you work it. __________________ You can't fix stupid....however ignorance can be cured through education!

June 17, 2020, 12:28 PM	#6
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,875	Its that you are cutting to much off the mouth at once , meaning when the cases are sized they are growing in length longer then normal . I get this with once fired NATO brass . The burrs and cuttings build up at the case mouth jamming the pilot up . This does not happen if I’m only trimming a few thousandths . If the case is supported enough try to trim with out the pilot . That’s what I have to do with my Lyman universal case trimmer . If I'm right the insides of the case mouths have smear marks from the cuttings rubbing between the pilot and inside of the case mouth . This is what mine looked like , note the shiny inside top edge . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again . Last edited by Metal god; June 17, 2020 at 12:47 PM.

June 19, 2020, 08:03 PM	#12
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 6,875	The throat is not the part of the chamber that involves case length . The trim to length and max case length are the same for both 223 and 5.56 . A way to understand that 223 and 5.56 case Dimensions are the same is understanding that they don’t make 5.56 dies you just use a 223 dies for both . There’s no statistical difference between the brass and what you size it to between 223 and 5.56 . This is not your problem your problem it’s not that one rifle is a 556 and the other is a 223 . If anything your problem is one rifle has a chamber that is very generous but still within the specs of 223 .i __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again . Last edited by Metal god; June 19, 2020 at 10:12 PM.

June 16, 2020, 06:46 PM	#3
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	I understand how this can be a problem if the cutter is too worn, but it should occur with ALL .223 cases. The same is true if the pilot or expander ball is the problem. But why would it work well with my .223 and not another?

June 16, 2020, 09:35 PM	#4
Shadow9mm Senior Member Join Date: March 21, 2012 Location: Indianapolis, IN Posts: 3,969	resize some of his brass and yours, measure the inside of the neck, neck thickness and outside of neck, see if there are any differences. One other though, yout trimmer head might be dull, causing a burr on the inside of the case mouth making it grab the pilot. if his brass is longer and you are taking off more metal this might be the problem.

June 17, 2020, 09:04 PM	#7
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	Shadow9mm, his brass may be longer, but would this occur if he had a 5.56mm rifle and not a .223? When I check to see what has to be trimmed,I just set the caliper at recommended max length and anything that doesn't fit gets trimmed. I have not measured how far over max his cases may be. I will have to do that. big al hunter, I was trimming in steps to overcome this, and at various increments I went so far to champfer and deburr, then continue to trim to the stop. But that is taking all the fun out of handloading these .223s. metalgod, thanks for the photos. I will check these cases to see if they look like the ones you posted. I hesitate to trim without a pilot as the unsupported case seems to whip around too much. Unfortunately the only smaller pilot I have is .17 caliber and that leaves a lot of wiggle room as well. This neighbor wants to get into reloading so this is a good lesson for him as well. He will do all the work with my equipment under my supervision right now, and when he feels accomplished, he'll invest and load on his own. Maybe I'll advise him to keep his .223s aside and use my inventory as I have a few thousand cases. But back to the difference between a 5.56mm and .223. Would his fired cases be longer if he really has a 5.56mm and not a .223?

June 18, 2020, 01:34 PM	#9
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	Thanks, metal god. This is not the first time I've had this problem, and the last time it was corrected by replacing the trimmer cutter. I did that again, to no avail. I resized both his and my cases in the same die, and my cases had no problem with the pilot - only his. So I think it makes sense that maybe his chamber is larger and the cases get longer when sized. I'll measure a bunch pre- and post-sizing and compare them to the measurements on my cases.

June 18, 2020, 02:23 PM	#10
rsnell Member Join Date: January 25, 2011 Location: Cleveland, TN Posts: 74	I believe Metal God has the correct answer. 0.223 inches is the diameter of the projectile and has nothing to do with the length. In addition, 0.223" converted to mm is 5.6642 mm.

June 19, 2020, 02:41 PM	#11
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	" 0.223 inches is the diameter of the projectile and has nothing to do with the length. In addition, 0.223" converted to mm is 5.6642 mm." The issue was not the diameter of the bullet, but the length of the case. The 5.56 NAto throat is 0.125" longer than the .223 rifle. The question was if a standard .223 case is fired in a 5.56 NAto rifle, will the case expand to a longer length, and if I trim it to a conventinal .223 length will the excess brass cause the pilot to bind when trimming. Even more confusing, however, is trying convert bullet diameters from inches to mm. It s true that .223" = 5.6642mm, but the Nato chamber is listed as 5.56mm, which is really 0.219". Worse, both the .223 and 5.56 fire a .224" bullet which is 5.69mm The difference between any two may be the diameter of the lands versus the grooves. Look at 30 caliber bullets; they are .308" in diameter which is 7.82mm, yet the 30 caliber rifles are labeled 7.62mm, which is really equal to 0.300"

June 20, 2020, 10:04 AM	#13
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	" If anything your problem is one rifle has a chamber that is very generous but still within the specs of 223" Got it! That makes sense.