Is there a military surplus mag pouch that will accommodate the 30 round ak74 msg?
My ak74 mags are too long for my com-bloc pouches

lol?
https://www.classicfirearms.com/ak74bommpd4magsandpouchdeal

I would think if you find a pouch that fits an 'AKM' magazine, it would fit a '74 mag' even better...

http://www.strikehardgear.com/

http://www.circle10ak.com/holstersslings.shtml

Also, FWIW. I have a 'Condor' Recon rig (I think), it actually fits AKM mags just fine, can even get M1A mags into it (though pretty tight). Of course 'the tops' of the mags will stick out, it isn't designed to fit completely in, even with AR15 mags.

My M4 mag pouches fit '74 mags just fine, try looking for some AR mag pouches that you like.

I purchase the surplus 4 magazine pouches from Classic Firearms. Then I take the strap from a M60 100 round belt holder. Remove the sling, toss the boxy belt holder, And the Sew with a needle and thread the sling part onto each side of the magazine pouch, and then they can sling across the body or off one arm as you like and work great. Cheap and homemade but better than paying 40 bucks for a 4 or 6 mag pouch. Ill post some pics when I can. Have had people at the range offer to but them from me. But I just show them what I did and let them sew themselves. Fun little project. Also much better than sliding your pants belt thru them.