Are you handy at all? This was my 3rd or 4th version of a chest rig, super easy with almost any exhisting holster. With some kydex or warmed up pvc and some clips this took all of 10 minutes.
It's a swaprig holster.
SwapRig Holsters - Love Your Rig... Swap Your Carry!
You buy a chasis and the custom molds that bolt on are like $15 each. Can go iwb or out with the belt loop, comes with extra clips. It's super versatile and I love it. However if this is the only use (and you're a little soft around the midsection like me) maybe find something else. My gut occasionally would pinch a bit between the corner and the waist belt on your pack, not a big. Pretty minor though. I've got an XDS but opt for the 12rds of .40 more regularly.
It was my first time going chest and I'm never going back. Easier to access, still haven't if you take your pack off, you'll know if it falls out, more room on waist for pouches or whatever.
So my suggestion is find a holster you like, a few straps around the house, a couple buckles and a 1' square of kydex and you can make it however you'd like and save $100 or so.
If you're more the type to just buy something, I've heard these are good.
Kenai Chest Holster – GunfightersINC
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