Most chest rigs and LBV are designed to work with and for the M4 that our military currently uses.  But I wonder if there isn't something with a focus towards the M14?  

It sounds like most double M4/AR mag pouches will fit an M14 mag just fine.  Otherwise, you can go with something modular and get the Tactical Tailor M14 mag pouches for that.

I just got done putting one together for my AR10.

Eagle Industries MOLLE Tav vest
4 HSGI rifle mag pouches (will hold two M14 mags each)
2 Spec Ops X-4 pouches (will hold three M14 mags each)

I've also added HSGI pistol mag pouches and a TT strobe pouch.

Will I ever carry 14 loaded mags...probably not...could I if I wanted to...hell yes.  I use the Spec Ops pouches for general use and misc. itmes.

The Eagle vest is VERY nice as well as the HSGI puches.  These pouches are great.  They have internal dividers velcro on/off capability, side-release buckles and bungee tighteners.  It took a little while to get them broken in but mags go in and out easily now.

HSGI's "Warlord" holds (16) AR-15 mags or (10) M-14/FAL mags.  Their "Dach" holds (8) M-14/FAL mags or (12) Ar mags.  I like both because you can switch between AR & M14/FAL w/out having to switch pouches.  Both vests also have numerous handgun mag pouches.

Which chest rig is that?  BHI, Eagle, SDS?

Tag, I'm interested.

BTW - there was a great thread by a guy named "triggerman" on the M14 forum started late last year. I can't go there right now to find the thread for you but it's a very informative one. The guy took a good training class and worked his equipment over and reported the results (like happens all the time here, but he used his M1a ).

IIRC he has switched from a harness type arrangement to a plate carrier as a result of his training experience... Not to influence your opinion at all, but just reporting his experience.