.223 vs 5.56

Originally Posted By: Jack RobertsThere is a lot of CYA BS out there.
Fact; 100s of millions of rounds are shot interchangeably every year.
Fact; A lot of ammo is labeled as 5.56/223.
Fact; Most reloaders load ammo for either to higher pressures than SAAMI specs.

Jack

Fact: There are a few with half a face left. But they don't post, it's too hard to type.

Is it worth the risk? If you claim there is no risk, you're either lying to youself or ignorant. And that is a fact too. Physics are physics.
 
It also depends on how old the 5.56 ammo is pre mid 80's stuff had a 55 grain bullet. The m16 also had a 12" twist barrel. Not till the gov. tried to make a long range rifle with newer longer bullet, and 9 twist barrel did this become a issue. It's still the same case just a longer thoart. Most factary guns have a long thoart anyway so it does not make any diff.
 
Originally Posted By: ghjacobsIt also depends on how old the 5.56 ammo is pre mid 80's stuff had a 55 grain bullet. The m16 also had a 12" twist barrel. Not till the gov. tried to make a long range rifle with newer longer bullet, and 9 twist barrel did this become a issue. It's still the same case just a longer thoart. Most factary guns have a long thoart anyway so it does not make any diff.

Has nothing to do with a longer throat. Has to do with the dia. of the throat. If
you start out nearer to the bore dia. then the angle of the throat gets you into
the lands much quicker. More properly in a .223 it is the freebore we are talking
about anyway , not the throat.
 

Freebore and throat are quite different. A .223 chamber has both, A 22-250
doesn't have freebore. Study some reamer specs and you'll see the difference.
Freebore is straight and the throat is angled into the lands.
 
Freebore is the same as leade (or lead) and is straight or with only a tiny taper. The throat is tapered usually between one and three degrees and goes from the leade to the ID of the barrel lands.

Jack
 
Here ya go:

223chamberspecs.jpg
 
Here's a couple of other views. Kinda where I'm at.


BALL SEAT

The cylindrical section of the barrel cut just in front of the cartridge case

Ball Seat is the same as FREE BORE.



CHAMBER

The CHAMBER is the part of the barrel cut to fit the cartridge case.

The CHAMBER is all of the cut part of the barrel between the cartridge case head and the point where the lands are uncut.



FREE BORE

In a rifle chamber THROAT is also known as FREE BORE and is supposed to be groove diameter with the rifling cut out.

FREE BORE - the portion of the barrel from the end of the chamber to the beginning of the THROAT that is free from any rifling.

(Note: The term "free bore" or "freebore" is associated, by some people, with Weatherby rifles, where a longer unrifled area ahead of the case mouth was said to allow increased velocity with acceptable pressures.)



LEADE (LEAD)

The LEADE is the section of the bore of a rifled gun barrel located immediately ahead of the chamber in which the rifling is conically removed to provide clearance for the seated bullet. Also called THROAT or BALL SEAT.

The LEADE is is the area of rifling (lands) that begins at the end of the THROAT, and extends to the point where the lands attain their full height.

The LEADE is the area of the barrel from where the angle of the THROAT begins to where it reaches bore diameter.



THROAT

THROAT is the area from the chamber mouth to the rifled bore.

In a rifle, the THROAT is the unrifled portion of the barrel between the chamber mouth and where the lands begin.

On a revolver, THROAT is the part of the chambers at the front of the cylinder where the bullet rests (or should), )

In a rifle chamber THROAT is also known as FREE BORE and is supposed to be groove diameter with the rifling cut out.



Pacific Tooling calls the ball-seat the 'lead' and the angled section the 'throat'. Clymer calls the ball-seat the 'free bore' and the angled section the 'throat'. Beats me?.................Dan
 
Lots of AR lower receivers have .223/5.56 stamped on them. But the mfg of the receiver has no idea what barrel is going to be attached to it during its life. It's surprising more guys can't figure that out.

Shoot .223 only in a .223 chamber until you know it's a Wylde or very similar.

Glass eyeballs look ok, but you can't see very well out of them.
 
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