Is this a bad idea?  I wanted the 14.5" barrel for the shortest overall rifle.  However, Bushmaster only offers 1 in 9" twist vs. the true M4's 1 in 7" twist.  Should M4's only be in 1 in 7"' twist barrels?  

Quoted: Is this a bad idea?  I wanted the 14.5" barrel for the shortest overall rifle.  However, Bushmaster only offers 1 in 9" twist vs. the true M4's 1 in 7" twist.  Should M4's only be in 1 in 7"' twist barrels?

Bushmaster has a 1/7 14.5 M4 barrel, you have to call them for availabilty and if you watch the EE they pop up on there every now and then.

Good idea.  I will call.  However, is the 1 in 9" twist  a poor choice?

Quoted: Good idea.  I will call.  However, is the 1 in 9" twist  a poor choice?

Not at all, I have a Bushy 1/9 14.5 M4 barrel and it is accurate with both 55 and 62 grain bullets. The 1/9 twist is probably the most versatile twist rate allowing a wide range of bullet weights.

I thought I had read somewhere that 1 in 7" is better for the shorter barrels to increase velocity which, in turn, increases fragementation.  

Quoted: The 1/9 twist is probably the most versatile twist rate allowing a wide range of bullet weights.

IF you listen to Bushmaster.

There is no reason to  use 1/9 on any rifle, period, UNLESS you intend to shoot ultra-light bullets....

Given that 55gr is on the 'too light' side for the M4, there's no reason for a 1/9 bbl on a M4-style rifle...

Does everybody agree that an M4 14.5" type barrel should only be in  1 in 7" twist ?   I had ordered 1 in 9" since Bushmaster's web site doesn't advertise 1 in 7" and my dealer told me they were not available.  I called Bushmaster and they are available.  Thanks for the responses.

Anybody out there?  

I have both, a Bushy 14.5 1/9 and a Colt 14.5 1/7 and they both shoot great for me. From what I've read on this thread most guys favor the 1/7.

I received an email back from Bushmaster on the 1/7 barrels they told me they offer 14.5 barrels M4 profile or HBAR $220 for barrel only assembly and $250 for complete assembly and $30 extra to add the phantom and that was from Jim Eden,Technical support.I dont know if they offer the same with 20" barrels but they do for 14.5 barrels in any event $250 plus shipping for a barrel only and phantom beats the $400 to $450 price for a compareable colt assembly.I want a 1/7 because Im building a carbine as close as I can to the military version.I love HBARs so Im going 1/7 HBAR so I can also use it with the 80 grain bullets making this carbine good for fighting and medium range sniping.

Thanks for the replies.  I went with the 1 in 7" barrel on my 14.5" Bushy M4.  Bushmaster said it would be 4 to 6 weeks before delivery vs. only 2 weeks at the most for the 1 in 9".  They said they make them primarily for foreign distribution.