AR newbie question for the experts

[Friday@7]

I recently purchased my first AR. A Bushmaster A2 carbine 11.5" barrel with a 5.5" welded/pinned flash hider. I have yet to shoot the rifle but hoping to get it out to the range over the holidays. I have several questions for the expert AR operators here.

1. Besides the initial clean and lube of the rifle (as the owner's manual suggests), is there anything else I need to do prior to firing the weapon for the first time?

2. Due to the shortened barrel, what type of velocity decrease can I expect? As stated prior, I have 11.5 bbl with a 5.5 supp 1/9 twist.

3. What is the difference between .223 and 5.56 ammo? I'm sure this has been asked a million times here so I apologize in advance.

4. I have heard several rumors regarding a defective extractor that is commom on BM rifles. Is this something I should be concerned about and have addressed prior to using the rifle?

Thanks in advance for any replies.

[GixxerSixxer]

1. Safety check. On an empty chamber drop the bolt and "safe" the gun. Pull the trigger. It should not go off.

2. Don't know, sorry I'm no help.

3. They are nearly the same. You can shoot either one out of your Bushmaster. Someone else is probably able to post a comparison pic for you.

4. There is a spring that you can replace to make extraction more reliable. BM doesn't use the proper spring that should be used. Some people have problems some don't. w.ar15.com will have a ton of information about how to change out the spring and where to get the spring.

[X-ray Dave]

Make sure the gas key is properly staked.

[Errick]

http://www.ar15.com/content/guides/

More info than you will ever need.

:thumbsup:

[RMTactical]

First thing I would do is trade/sell the barrel or upper for a 16" barrel.

I find the 11.5" barrel with the 5.5" flash hider to be quite ridiculous because you sacrifice a lot of velocity for nothing because the flash hider sucks and you still must retain a 16" overall barrel length.

Read this to learn about the differences in .223 and 5.56.

http://www.ammo-oracle.com/body.htm

[Skintop911]

Originally posted by Friday@7
1. Besides the initial clean and lube of the rifle (as the owner's manual suggests), is there anything else I need to do prior to firing the weapon for the first time?

Do a search for previous threads on new rifle reviews, acceptance inspections, etc. There are several. While not exhaustive, they hit the high points of what to look for.

2. Due to the shortened barrel, what type of velocity decrease can I expect? As stated prior, I have 11.5 bbl with a 5.5 supp 1/9 twist.

Substantial loss of velocity, but not unmanageable.

3. What is the difference between .223 and 5.56 ammo? I'm sure this has been asked a million times here so I apologize in advance.

Echo Gorelicks' advice to read the Ammo Oracle.

4. I have heard several rumors regarding a defective extractor that is commom on BM rifles. Is this something I should be concerned about and have addressed prior to using the rifle?

Not a rumor, the issue is well documented. "Defective"? Not in all contexts. Sub-optimal and incorrect, certainly.