What is the safe minimum barrel wall thickness for 5.56x45?  I'm having an HBAR barrel custom turned and fluted and was wanting the area forward of the FSB turned to .675 and then cut with .090 deep flutes.  Minimum wall thickness for this setup would be .130 - any problem with that?

TIA

Tate,
hopefully the gunsmith doing your work can supply this answer.  If you're doing a double check on your supplier, you might give Kurt's Kustom a call.

5subslr5 - great minds think alike.  The rifle has been in Florida at KKF's for the last week.    Just been a couple of weeks since I asked him this Q and I haven't seen an answer yet - other replies from him, but no answer on this.  I know he's a smith, not in the business of running a "Dear Abbey" column, so I figured I'd give the question a whirl on this board since I wasn't able to find this info doing a net search.  Thanks.

From: www.riflebarrels.com/bweight.htm

[qoute]The program has some built-in safety devices. If the barrel cylinder diameter is no more than .1" over thread shank diameter, a warning will be printed. If the length of the flutes is within 2" of the overall barrel length, you will be told. For flutes machined to within .100" of the groove diameter, you will be warned. When using the pre-programmed barrel tapers, you will be notified if too much length has been trimmed from the chamber end and the overall barrel length would exceed a 29" blank length.

Soooooo - it looks to me like I'm safe with the .138 and .130 minimum wall thicknesses.

Safe to take the barrel to this minimum thickness per Kurt.