I have decided (thanks to much reading and advice from this board) to buy a Bushmaster M4 A3 w/ collap stock (my wife actually wants for me to get one!) hopefully for Christmas. I got to finger one Saturday in a shop but saw something that raised a question.  

I want the option of putting a flip-up front sight on but the fixed front sight on the Bushmaster appeared to be perm attached to the barrel. Is this true? So if I want to be able to remove the front sight and replace it with a flip-up (so I wont see the front sight through optics) will I have to special order a Bushy AR or buy a new barrel, front grip, whatever it takes? I don't want to have to spend $800  (AIM surplus) to $1000 (local shops) for an AR that I'll have to replace a barrel or something else in the future only to install a flip-up front sight. Should I look at a different manufacturer? Two different shops in the area have quoted me prices of appx $900 and $1000...too much money to not get what I want.

Also, can you have a phantom flash supp installed at the factory on a new gun before they ship in place of the bird cage?

Thanks for the help for a newbie to AR's...

Yes they will permanently attach a phantom on a 14.5 at the factory $34.95 they charge.The FSB is not permanent but held on by 2 solid roll pins and the attached gas tube.It can come off but its a PIA.You could order it with the shaved front base and Bushy will add their fold down front sight that goes over the original base or you could send the upper to YHM yankee hill machine and they will install one of their units that has the fold down front built in.So if you want you can order it from Bushy the way you want it or go with another company if you dont like the Bushy fold down front.The great thing is as long as you buy the parts from them they dont charge labor and they will build it the way you want.I have found that unless you are going to use magnified optics the front sight is fine as you can co witness it to a red dot.If you are going to use multiple types of optics go all flat on top.You could always go with a swan sleeve that has the ARNS#40 rear fold down built on it plus it gives you 1" of elevation or rise that most red dots need and the fold down front that needs no modifications if the base is flat wich you can order that way if you want...look at their modular carbine model that comes that way and pick and choose the options you want accordingly.

Quoted: I have decided (thanks to much reading and advice from this board) to buy a Bushmaster M4 A3 w/ collap stock (my wife actually wants for me to get one!) hopefully for Christmas. I got to finger one Saturday in a shop but saw something that raised a question.   I want the option of putting a flip-up front sight on but the fixed front sight on the Bushmaster appeared to be perm attached to the barrel. Is this true? So if I want to be able to remove the front sight and replace it with a flip-up (so I wont see the front sight through optics) will I have to special order a Bushy AR or buy a new barrel, front grip, whatever it takes? I don't want to have to spend $800  (AIM surplus) to $1000 (local shops) for an AR that I'll have to replace a barrel or something else in the future only to install a flip-up front sight. Should I look at a different manufacturer? Two different shops in the area have quoted me prices of appx $900 and $1000...too much money to not get what I want. Also, can you have a phantom flash supp installed at the factory on a new gun before they ship in place of the bird cage? Thanks for the help for a newbie to AR's...

You've got several options.  Bushmaster sells a clamp-on/flip-up front sight that will attach to a milled front sight base,  and a detachable /flip-up that will attach to a rail type gas block like this one.  You have the correct idea about the fixed front sight (or any type of gas block you want).  It's best to decide what you want and let Bushmaster (or whichever manufacturer you choose) install it....from what I understand, they are a major PITA to change.  Either way you have lots of options; I'm sure the above are not the only ones.

Mike

If I special order the AR from Bushmaster (with the phantom and flip-up front sight) do I then have to pay their full suggested retail or can I still buy the gun through a local shop at a slightly discounted price?

Anybody have anything against  the bushmaster flip-up front sight?

If I get the fixed front sight for the time being will I have to spend any extra money besides buying a flip-up front sight and labor? Does the gas tube have to be replaced since it is attached somehow?

Thanks again for the assistance.

Edited to account for previous posts information...