can you rechamber an AR15 5.56 to a .223?


December 6, 2008, 04:07 PM
my Shaw Bull barrel came chambered as a 5.56 so when I go to Gauge the OAL the bullet would be way to long (2.400 with 55gr v-max) because the chamber of the 5.56 has a long throat as apposed to the .223. so my guestion is can it be rechambered into a .223 from a 5.56? or am I just stuck with alot of freetravel?

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December 6, 2008, 04:48 PM
The differance, as you already noted is mainly more free-bore and a slightly looser chamber in the 5.56.

You can't put back metal with a chamber reamer that is already gone.


December 6, 2008, 05:20 PM
You could rebarrel the upper or just buy another upper. I think that's about it.

Dr. Tad Hussein Winslow
December 6, 2008, 09:21 PM
Yeah, that's like trying to make your hair longer - not gonna work.

December 6, 2008, 09:24 PM
I Never thought I would hear about someone who wants .223 over 5.56 chamber. But each to his own. I guess for absolute precision, a tightly chambered .223 might be the better route.

December 6, 2008, 09:25 PM
as far as i know 223 will shoot just fine in a 5.56 chamber
shoots fine in my AR's

December 6, 2008, 10:11 PM
My AR shoots 3/4" @ 100 easily with a 5.56" chamber, good enough for what I do to 300 yards.

December 6, 2008, 10:26 PM
when people rechamber something, it's generally assumed that they're moving the chamber forward where there is plenty of material.

the caveats would be that you need enough shank left on your barrel and you need the overall length to be a good bit longer than 16" so when you cut some off the back of the barrel and rechamber, it's still over the legal limit.

the problem with doing this in an AR is that your gas port is now in the wrong spot. so, i suppose it's possible to plug the hole and drill a new one. it's also possible to shorten your gas tube.
i wouldn't recommend either though.

especially if the whole point of this is to seat your bullets into the lands, which i still think is something you don't want to do.

December 6, 2008, 10:55 PM
Get a new "wylde" barrel

December 6, 2008, 11:06 PM
Get a new "wylde" barrel


Wylde chambers are great.

December 6, 2008, 11:21 PM
Vice-versa may not bode well, but all hail the 5.56mm caliber. Even the World-Wide devastating Ruger Mini-14 handles both configurations very well. So what remains, but specific BULLET selection. Is the Nosler 60 grain Partition bullet the deadliest .224 pill on EARTH? To date, I'm prone to scream, "YES!" I know Swift Bullet Company could contradict me, but thus far this hasn't happened. America NEEDS better bullets for homeland defense. cliffy

December 7, 2008, 09:53 PM
im very aware i can use .223 in my 5.56. my problem is this. I got the gun new with a m4 16" barrel which shot 2" groups, then i free floated the 16" barrel and it shot 1 1/2" to 2" groups. I got a new 24" stainless freefoated Shaw barrel and it still shoots 1 1/2" to 2" groups. Ive gone from 45 to 50 to 55 to 69 to 75 gr bullets ranging from moly coated, v-max, hpbt to blitzking, also all kinds of powders like h322, benchmark. Ive also tried 3 scopes. I know what your thinking, its probably the shooter. well its not. I can get behind anyone elses AR or bolt action and shoot sub groups. Its not the shooter, I have a very steady hand and know how to shoot, its just this one AR I cant get to group. Im now thinking that the gas hole in the Bull barrel is nicking the bullet as it passes and causing a brass tear so im taking to the gunsmith to have it checked out monday. Ill update. if you have anything that you think might be an issue please let me know. Im almost ready to sell it and get a good remington 700 in 22-250. well im getting one anyhow but still if i cant get thing to group its history.

December 7, 2008, 11:52 PM
if you want sub-moa, perhaps buying another is the way, but 1.5" groups are still quite good. Guess it depends on what you use it for.

December 8, 2008, 01:27 PM
You can buy a quality match barrel and have it installed for a reasonable amount of money.

Swap the barrel.

December 8, 2008, 01:42 PM
Im now thinking that the gas hole in the Bull barrel is nicking the bullet as it passes and causing a brass tear so im taking to the gunsmith to have it checked out monday.You should be able to check that yourself with a cleaning rod and a tight patch. If there is a bur, you would certainly be able to feel it.

Also, try dragging a Q-Tip in & out of the muzzle. Look for cotton fibers sticking on a bur in the crown. That would do it.

How is your trigger?

If it is heavy & rough, that might be causing you problems.


December 8, 2008, 03:47 PM
yea when I run a jag through it I can feel the hole very distinctly. when I got the Barrel new I could see burs from where the gas hole was drilled, I ran a brush through it and shot a few hundred rounds of some cheap fmj doing the oll stainless new barrel break in, jagging after every 3 to 5 shots, and thought that might fix it. but now that im using top of the line reloads its still throughing flyers all over the place. Ill get two or three that are 1/4" then theres a flyer 1 1/2 to 2 " out there. I even waited a minute between shots thinking it was the heat. my trigger is a 2 stage jewel trigger. very nice trigger. I know its not that. Im trying to find a place I can shoot some fmj's into water and see whats really happening to the bullet after it leaves the barrel. that would tell me if its the barrel or not for sure.

December 8, 2008, 03:58 PM
here is a pic of my gun

December 8, 2008, 04:09 PM
that would tell me if its the barrel or not for sure.I don't think you will be able to recover enough of a FMJ shot into water to tell anything.
They will blow up just like a SP/HP at "recovering" ranges.

Suppose you could handload them way down on velocity and catch them that way.


December 8, 2008, 04:14 PM
AS an absolute last resort before replacing the barrel and or gun you could try firelapping your bbl using the tubb system. At this point it sounds as though you have nothing to lose

December 8, 2008, 10:44 PM
well i just gone done cleaning the crap out of the barrel. I used a copper wire brush a few hundred times and jags a few hundred times with hoppe's #9 and hoppe's copper lead and carbon remover and blew gun scub through it a few times untill i got blue patches then almost no blue. then i took the gas block off and ther it was, a buildup of copper fragments that were wedged up in the hole very tight along with shreds of old patches, I had to force them down into the barrel then push the grime out the end, Im hoping this is all that was wrong with it. Im still taking it to the shop tomorrow to have him look at it through a bore scope and see what he says. but it made me feel good to get that build up of copper and stuff out of that hole. I dont know how the gas system was even working. but its nice and clean now, after I go to the shop, depending on what we find, Ill swing by the range and pop a hundred or so at 100 yards. update tomorrow night.

December 10, 2008, 02:01 PM
I took it to the gunsmith yesterday and he looked at it and said it was a little rough around the gas port so he gave me some tiny files and told me to file the inside of the hole, he said he could do it for me but I just asked him what to do, he told me and sent me on my way, I got home and did about an hour an a half of filing, those files are tiny, I could feel the file catching on the rough edges, after it was all smoothed out i put the gas block back on and waited untill this morning to hit the range
well it looks like my awesomely awesome gunsmithing skills worked. just got back from the range and after sending 60 rounds of 55 gr fmj's 100 yrds down range for a little break in and getting 1 inch groups then putting a brush through the barrel with hoppes then a couple jags through it, i sent 3, 5 round groups of 50gr V-max 100 yards down range and here they are. It just needed some work done to it, which is what makes this hobby so fun to me. trial and error.

December 10, 2008, 07:06 PM
my buddy's 5.56 cracks all his 223 brass from mouth to neck. maybe he just has a bad lot though.

December 11, 2008, 09:19 AM
I have a Bushmaster 24" stainless 5.56 chambered Heavy Match barrel that will shoot sub-minute of angle out to 300 meters using 60 grain spire soft point handloads out of commercial ,223 cases.

I am just guessing here, but my guess is you may have gotten a bad barrel.

If Shaw barrelled it, send it back, they should make things right.

Whoops, my bad, I didn't read your picture posting,,,,,,

December 11, 2008, 04:38 PM

Those are very nice groups. I couldn't find where you detailed your hardware. What type of gun is that Shaw on? Is that your own build? What type of scope?

December 16, 2008, 01:35 PM
its a bushmaster lower, 2 stage jewel trigger, bushmaster upper and bolt, 24x Bushnell Banner scope,

December 16, 2008, 04:38 PM
nice gun! nice groups!

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