What the heck did I buy? (longwinded)

[iamkris]

Yeah, well, given that there were no less than 4 factual errors in the post (e.g., 5.56 = .223, muzzle brake denotes post-ban only, ACE stock denotes post-ban only, optics are no good for combat), I shouldn't have given it any attention either but I just couldn't let that one fly.

 

[nipprdog]

I'm not sure which is worse;

his advice, or his grammar.

 

[anapex]

Just to add to your it's an Armalite upper theory. The brake on my Armalite looks exactly the same. Now that doesn't mean they didn't take a brake off an Armalite but hey I guess anything could happen. That's quite a nice setup too, makes me want a flattop now.

 

[blfuller]

Didn't see anyone else mention it, but that doesn't mean they didn't, but your removable front sight is installed backwards. Not that it probably will affect anything. Just an FYI. Vertical surface should go towards muzzle and the angled surface goes towards rear sight.

 

[mummac]

Didn't see anyone else mention it, but that doesn't mean they didn't, but your removable front sight is installed backwards. Not that it probably will affect anything. Just an FYI. Vertical surface should go towards muzzle and the angled surface goes towards rear sight.

I have it that way for aerodynamics. Just kidding of course. Thanks for pointing that out.

The brake on my Armalite looks exactly the same.

Thanks for the info. Does your Armalite have a rubber coating around the barrel? Also, does it say .223 and 5.56?

 

[GigaBuist]

Erhm, just to clarify.

It should be pointed out that Milspec ammo(5.56x45) is almost allways load to high pressures that commercial(.223 Remington) (SAMMI). It a CYA for the US ammo companies.

Milspec ammo can be fire in any firearm in good condition. That a judgement call that you the owner has to make.

I wouldn't test the theory. The 5.56 round, as has already been stated, can reach higher pressures than .223. Sometimes. Might work most of the time, but I wouldn't be shoving 5.56x45mm surplus stuff from some random country into a Mini-14. Now, through an AR chambered for 5.56, yeah, sure.

I would not try to fire 9mm SMG ammo in say a WWII Lugar, but a Glock should not be problem.

I wouldn't recommend firing 9mm ammo that isn't within SAAMI specs out of anything unless the manufacturer said it was OK. Since I don't own an SMG that's kinda a moot point for me.

There are times when a Milspec. rifle is NOT recomended for use with commercial ammo. The only example I know is Springfield Armory's M1a where only US GI ammo was recomended.

This, right here, is where the confusion lies, I think. I sometimes forget myself.

5.56x45 in a .223 chamber is NOT safe.
7.62x51 in a .308 chamber IS safe.
.308 in a 7.62x51 chamber is NOT safe.
.223 in a 5.56x45 chamber IS safe.

For the two most common catridges that are soooo close in US military and US sporting rifles the logic flips. It seems that creates confusion amongst people; myself included! If I'm wrong, somebody, for the Love of G-d, correct me!

Edit:

BTW, nice rifle! Sounds like a pretty good setup for you, and I'd kinda like one myself.

 

[mummac]

Being confident that I have an Armalite upper, I decided to poke around on their website concerning the .223/5.56 debate. The site was down for a few days and when it came back up, I found this:

ArmaLite has adopted a practice of using a special, modified SAAMI chambers in its stainless steel match barrels. This chamber is better for match use than the NATO chamber, but fires the NATO ammunition perfectly. We use the NATO chamber in all moly (phosphated) and chrome-lined barrels.

http://armalite.com/library/techNotes/tnote45.htm

So, for this rifle I feel comfortable shooting both. Thanks again for the replies.

 

[anapex]

Thanks for the info. Does your Armalite have a rubber coating around the barrel? Also, does it say .223 and 5.56?

Nope no rubber coating around the barrel on mine. My guess something like that would have been a not from the factory addition but I could be wrong.

 

[RTFM]

The whole blurb from the Bushmaster site/catalog.

.223 Remington or 5.56mm: We’ve had numerous inquiries about .223 Rem. versus 5.56mm NATO
ammunition.
The short answer is that all Bushmaster barrels are chambered for the 5.56mm cartridge. Most of our barrels are stamped 5.56 NATO - usually just ahead of the front sight. Despite the fact that our Lower Receivers are stamped CAL.223-5.56MM, our chambers, barrels, and bolts are designed to withstand the higher pressures of the 5.56mm cartridge.

We do this for the safety of our customers, and because our rifles have always been built following the military pattern.
In any of our barrels, the .223 Remington cartridge can be fired safely.

So, what’s the difference between the two cartridges? They have basically the same exterior dimensions and length, but the 5.56 is usually loaded to produce higher velocity and chamber pressures. It has thicker case walls
for the extra strength needed to handle those higher pressures. The difference comes in the chambering of the rifle, and that difference is in "Leade" (more commonly known as the throat) which is the portion of the barrel directly in front of the chamber where the rifling has been removed to allow room for the seated bullet.
In a 5.56mm chamber the throat is typically .162" – in a .223 chamber it’s usually .085"(about half that dimension). The result of firing a .223 cartridge in the Bushmaster 5.56mm chamber is a slight loss of velocity when measured against the 5.56mm cartridge.

However, if you own other (non Bushmaster) rifles specifically chambered for the .223 Remington, you should not use 5.56mm ammunition in them as it is considered by SAAMI (Small Arms and Ammunition Manufacturers Institute) to be an unsafe ammunition combination. (This 5.56mm/.223 Rem. information from Bushmaster Gunsmithing and the Winchester Law Enforcement Ammunition Website.)

justsurvivingincalifornia, you are incorrect.....
RiverwinoIA, you are also incorrect.....



Where do people get off giving incorreect information?
If you don't know ask, but PLEASE PEOPLE for other saftey sake DO NOT MAKE IT UP AS YOU GO ALONG!

I would hate to hear that someone jams a 5.56 round in to a reciever that is manufactured for .223 becouse the information thay have is bad, becouse someone on a gun friendly internet information web site said

"First thing first the ammo is the same 5.56x45 is the same as .223. That just the civilan name for the cartridge"

Ouch! That hurts to read.....

there is some difference between .223 and 5.56, .223 is usually target/match rifle, 5.56 is usually for defense.

*sigh*
:banghead: