Reaming a .223 rem to 5.56 military?

[mannyrock]

Dear Guys,

   I like the looks of alot of the newer bolt action rifles that are out in .223 Remington, but I have never bought one because I understand it would create high pressure to try to fire the standard 5.56 military rounds in them

   How hard would it be for a competent gunsmith to take a bolt action rifle in .223, and ream out the chamber so that it would handle the 5.56 military round? And, then reassemble and headspace it.  (Or, is this something that just can't be done?)

   If it can be done, any guesses as to approximate cost?

Thanks for all info.

Mannyrock

[trotterlg]

I think that, in most modern firearms in good shape, it just doesn't matter, the chamber dimensions and tolerances are so close to each other that they probably overlap.  The basic actions you will be shooting these little guys in are the same as the actions that contain the energy for 30-06's and 300 Win Mags.  This is just my opinion, I am not a gunsmith or an engineer, however I have never seen a documented case where a military round killed a civilian .223.  Ask your gunsmith what he thinks.  Larry

[bluebayou]

I'm with him.

I think that you are over-complicating the issue.  There just isn't that much difference in the rounds.  Whenever I see the warnings about 223 and 5.56 the only rational thing that I think of is that you can't trust all surplus to be NATO spec.  Some surplus will be hotter than others.  The NATO spec is hotter than 223 SAAMI, but I won't loose sleep over it. 

[Graybeard]

Dimensionally the really are the same round. The difference is pressure and twist rates not chamber dimensions.

[brennemanj83]

You can safely shoot the 5.56 through the 223 with no problems.I had Savage Model 10FP that I shot 5.56 rounds through all the time.

Dimensionally the really are the same round. The difference is pressure and twist rates not chamber dimensions.

GB is correct They are basicaly the same round with the only differences being pressure and twist rate.If the Savage 10 actio wasnt able to withstand 5.56 pressures it sure wouldnt hold up to the 300WSM and other high pressure rounds.....Just My 2cents

[mcwoodduck]

Of the 223's I own the only one that has problems with the 5.56 is the T/C contender.
And it is with stuff that is labeled 223 on the box but 556 on the case. (Federal American Eagle 55 grain FMJBT)
I have found that anything comming from the factory with a FMJ bullet seated on top is going to be loaded to 5.56 specs.
My Remington M700 SPS in 223 does just fine shooting the 55 grain FMJ Boat tail from American Eagle.  I like this round for my AR15 when I shoot high power matches.  I say this only because the M700 has 1:12 twist.

[Steve P]

Difference in chamber dimensions (from .223 go gage to 5.56 field gage) is minimal  (about .005" I believe, but don't quote me on this.)
SAAMI spec is about 55k psi for .223 and NATO spec for 5.56 is about 63K.  You should be able to safely shoot a .223 round in a 5.56 military gun, but should not, according to the experts, shoot a 5.56 military round in a .223 Remington.  I have three contender barrels in .223 and they do not know the difference in the two rounds.  No problems firing or extracting.  I have heard other folks have a heck of a time getting fired 5.56 brass out of their .223 contender barrels.

Most modern .223 firearms will withstand the pressures of the 5.56 round.  There are some inexpensive guns that are a little loose on tolerance that I would be very careful with and look for pressure signs before firing many rounds.  Some people feel that due to the smaller case and chamber, the gun has more metal in the barrel and receiver so is therefore stronger.  Not necessarily true.  The 5.56 NATO is pushing as much, if not more chamber pressure than the 7.62 NATO round.  Yep, more pressure than a .308 Winchester.

If you have a modern rifle that is made on the same action as some of the 65k psi cartridges like the 300 WSM, I don't see why you can't shoot the 5.56 loads.  My suggestion would be to call the Mfg and talk to the engineer.  If you can confirm the barrel and action go thru the same heat treating process and are made to same mfg spec, you should be golden.    Again, talk to the manufacturor to confirm fabrication or manufacturing specifications on action and barrel strength.

Good luck, but stay safe.

Steve

[chutesnreloads]

I would ask WHY would you WANT to shoot military ammo in your bolt action?I can understand if you shoot an AR-15 or the like but a bolt?I've done it with no problem except I've yet to see the military ammo shoot even nearly as accurate as my handloads or even a factory .223 load the rifle likes.If you need to shoot FMJ for some reason,buy the bullets and load 'em yourself.If it's just because they're cheaper I'd recommend  getting a good .22LR.

[gunnut69]

The difference is in the chamber tolerances. The 5.56 chambers are looser to allow for crud build up in combat situations. It also helps prevent cookoffs..some. No pressure problems should occur.
the twist rates in the barrel has to be compatable with the bullets length. Weight usually but not always equals length.

[torpedoman]

if your real set on doing it to be extra safe use a 223 wilde reamer that is made to use both with the best accuracy you can get using bote you can rent a reamer and do it yourself if you can remember that too much cutting oil is'nt enought you can do it.

[BullyDawg19]

you can rest assure that any relatively new rifle chambered in .223 will be more than adequate for the nato round. ive been told by several manufacturers that they "assume" that nato rounds will be used in them and are built to handle them although they state otherwise for legal purposes. they dont recommend the use of the nato round because of the inconsistencies of the surplus ammo.

[mannyrock]

Dear Guys,

  Thanks for all of the information.  No, I'm not intent on  reaming out a .223.  I just wanted to get some information.  All in all, I agree with the viewpoint that if I bought a brand new, high quality, rifle, it would be more than strong enough to handle a standard Nato round, but that the accuracy may suffer.

Thanks again.

Mannyrock