View Full Version : Questions about my new AR-15...

January 3, 2010, 06:14 PM
I just got a new AR-15 and at the store they told me that my gun can only shoot .223 and not the NATO round. They also said that it was an A2. However when I brought it home I noticed that it had a detachable carry handle and a flat top upper receiver. I also noticed that the barrel was labeled with 5.56 NATO and that the lower reviver also said 5.56 NATO / .223 Rem. The model is a Bushmaster XM15-E2S, what do you guys think?

January 3, 2010, 06:22 PM
Looks like the XM15-E2S is the model of your lower reciever, not your entire weapon. The lower has nothing to do with round the upper shoots, so this could make sense why it's labeled as both.


Does your upper have a model #? I've never heard of a commercially available barrel (from a big manufactuere like bushmaster, remington, etc) lieing about what it shoots. If it says it shoots the 5.56, I would have to assume it's right, especially before I assume a firearm salesman is right (sorry to all you educated salesman out there... I've just dealt with too many who weren't). But if you can find some model number, it would help look up the specs.

January 3, 2010, 07:35 PM
I don't see any markings on the upper but could the barrel be made to handle 5.56 NATO and the upper made to only handle .223?

January 3, 2010, 09:20 PM
barrel be made to handle 5.56 NATO and the upper made to only handle .223?

The barrel is the upper. The barrel plus the chamber and bolt carrier group, that is. Probably that was just a typo on your part and you meant to type "lower", but lets make sure you are clear on that first.

I don't have a lot of experience with 5.56 vs .223 and don't have a super amount of experience with commercially available ARs, so I can't speak of what Bushmaster has a tendency to do. My best guess is the rifle did not come as a complete rifle, but was pieced together and then sold as a single weapon. If this is the case, we would need to know more specifics on the upper.

I could be completely wrong.. I'm just going off the link I showed you earlier that it looks like the lower is purchased separately. If I am wrong, hopefully someone will be here shortly to correct me.

I feel like all I've done is repeat my first post with different words.. didn't mean to be repetitive! :)

January 3, 2010, 09:29 PM
If the bbl is marked 5.56, it should be safe to shoot 5.56.

January 3, 2010, 09:35 PM
If your rifle was factory assemblied by Bushmaster, it is chambered fot the 5.56 NATO round, and you can use either the 5.56 or 223 round. If your upper is a Bushmaster, look on top of the barrel, between the flash suppressor and front sight for the barrel markings. You should see lettering readings something like " BMP 5.56 NATO 1/9 ". The "1/9" means the barrel has a 1 in 9 twist. The markings may be faint due to the parkerzing finish.

January 3, 2010, 10:38 PM
Do what SVO said. Look for the markings on the barrel. About 95% of what Bushmaster sells has the 5.56 chamber.

January 3, 2010, 11:21 PM
Pull the handguards if need be. Bushmaster marks their barrels, so it should say either .223 or 5.56 NATO.

The only .223 only barrels I've seen for the AR are longer bull barrels for varmint shooting (or maybe the occasional HBAR intended for match competition).

Since your barrel says 5.56, I'd take that as gospel. You could have the chamber measured, but I can't imagine a barrel maker using a .223 chamber and labeling it 5.56- you'd be trolling for a lawsuit.

January 4, 2010, 05:17 AM
If the barrel is marked 5.56, you're good to go. Sounds like the guy who sold it to you had no idea what he was talking about.