I carry a P220 Carry SAO IWB in a TT Gunleather holster and want to get a mag holder. Need suggestions on either IWB or OWB and also single or double or two singles. Reasons for you suggestions greatly appreciated.

I use IWB mag holders that are well-trimmed leather. They give me the option of deeper concelament used in the pants or, if I gain a little too much weight, just carried between pants and belt (the belt usually has enough extra allowance that the pants don't).

I only carry one extra mag, but if I did 2 I'd prefer two separate single mag holders. They also give more options on positioning to curves in the waistline and spread the load/bulges around a bit more.

I carry two mags for single stack pistols. Hey, they're flat... so why the heck not? PLus the single stack pistols only carry about 1/2 of the ammo as the doubles. Not that much extra girth with an additional mag...

I actually like dreisigs method of two mag holders. In some cases, depending on the manufacturer, the double-mag holders don't seem to fit as tight or securely. My Kramer for the P225 is this way. Running around it's okay... but I was wearing that rig when I took a header down some concrete steps on morning & I ended up going on safari for one of the mags.

I don't think the OWB's add a lot to the concealment issue. So I'd say go with whichever ones feels better. Remember that the IWB mags ad that much more space you need to adjust for on you waist band & belt size. So OWB may be much simpler. If you're made carrying, most people would think that they were knife pounches or a cell phone case. At the thickness for a single mag in 9mm or .45 ACP I think they'd be barely noticeable.

I use TT Gunleather IWB for my P6 & 229. I like them because they are inside and I found that most OWB's don't have a body shield. I bought a really nice Mitch Rosen OWB but sold it because the base plate dug into my back. The TT's fit well and in the right spot don't dig in with the body shield.