First off, I'm new here.  I'm about to fork out some cash for an AR and I've narrowed my decision.
I've heard so many good things about the Bushmasters and I've found 2 that I really like.  Both are classified as their new "sunset" rifles.
One is the M4 with Izzy Flash, the other is their 16in carbine with the birdcage suppressor.  Both have a collapsable stock and ship with the 30rd mag.
I've searched all over this forum as well as on the Bushmaster website, but I can't seem to find a side by side comparision of these two rifles.  I'm looking for overall weight (empty), length (closed stock and open), as well as some tech details on the barrels.  Are these two both the same length?  Only difference being the M4 style barrel?  What about the difference between the two suppressors?  From this forum, I've determined that this Izzy is some form of muzzle break?  I really don't care about muzzle flash, but after shooting my friends RRA and nearly being deaf (even with earplugs) I'm wondering about the sound output of each.  Also do they have any performance advantage or disadvantage?
*whew* almost done.....
What about the rifling?  Are these 1:7 or 1:9?  Anybody have experience with either of these two firearrms?
Thanks for any input!

There are two forms of the Izzy - one is a brake and the other a flash suppressor.  Both are 2-3/16" in length, as are the three popular Phantom f/s models.  The A2 f/s is 1-3/4" long.  The bbl threads will use 5/8" of length on all of these, once installed.

If you permanently install an Izzy F/S or brake (or any of the three Phantom f/s models) on a 14.5" bbl, you end up with 16-1/16" overall bbl length.  A 14.5" bbl with the A2 f/s yields a 15-5/8" OAL bbl.  A 16" bbl with an A2 f/s would be 17-1/8" long.  A 16" bbl with an Izzy or Phantom would be 17-9/16" long.


Edited to correct the numbers.

Forgot to add:
Bushy bbls are almost always 1:9.  Anything else is either part of their DCM series (1:8) or part of a special production run.

Hey, thanks for the info.
I guess what I'm getting at is, do both of these rifles have the same bbl length?  Does the m4 style bbl have any accuracy issues (I realize that accuracy is a combination of skill, rifle, and ammo).
Speaking of ammo, any recomendations for these two?  I fed my old MAK-90 Wolf ammo and never had one problem, but I understand AR's tend not to like Wolf or Olympia.

Is the barrel you want 16" overall or 14.5" + Suppresor/Brake. Just as Chuckhammer mentioned the 14.5" barrel has to have a permanently attached muzzle device to make the barrel meet the legal limit of 16". The 16" barrel will be 17 9/16" after installation of muzzle device, also as Chuckhammer suggested. The 16" barrel will be slightly more accurate "They say anyway". But If accuracy is your number one priority maybe you should go with a Chrom-moly or a Stainless Steel Barrel. The barrels you have mentioned are Chrome lined 1:9 which makes them more durable, but less accurate. The muzzle device will have very little effect on your accuracy.

I have a Bushy 14.5 + Iggy Brake and I am very impressed with its accuracy. I feed it nothing but Wolf. I have shot about 500rds of it with out any malfunctions or jams. Its alright ammo, just burns a little dirtier than others. Just keep it clean and there will be no issues.

They do not have the same length bbls.  The M4 has a 14.5" which, once the (Phantom or Izzy) f/s is permanently installed becomes 16-1/16".  The regular carbine uses a 16" HBAR bbl which, once the A2 f/s is threaded on becomes 17-1/8".

The accuracy difference between the two, all else being equal, would be negligible.

The 16-incher would have an advantage in muzzle velocity of maybe 75-100 fps with 55gr M193 (Federal XM193 or Winchester Q3131A).  Note that these two loads are significantly "hotter" than regular commercial .223 which is loaded to SAAMI pressures rather the NATO pressure used for M193.

I strongly recommend that you read this page all the way through at least once.  Very educational.
www.ammo-oracle.com

Any and all questions you have about ammo quality can be answered here and here.

There is some really interesting stuff on those links, Its a handy link for answering most of the questions I see posted here on ARFCOM.

I especially like the link under SHTF ammo, with a link to the Aluminium Foil Deflector Beanie.

What is an IZZY?

Bob

Again, thanks.  That's what I was looking for.  I know overall length has to hit 16".  I just didn't want a super short bbl with an obnoxiously long comp on it.  Sure, I know some love the 11.5+5.5, but not me.  Think I'm going M4.....

Quoted: What is an IZZY? Bob

Izzy Brake and Izzy Flash Suppressors, are used on alot of Bushies. It looks similiar to a bird cage FS