I just picked up a Sig P238 last Sunday at a gun show, think I got a great deal, and was curious what suggestions you guys had as far as ammo.  The following are a few boxes I have on the test list, but please let me know if there are any others you recommend.  Also, if your ammo isnalready on mynlist tell me which you are using.

Hornady 90g FTX Critical Defense
Hornady 90g Zombie Z-MAX
Buffalo Bore +P 100g Hardcast FN
Buffalo Bore +P 95g JHP

Thanks
Mike

I run the Hornady Critical Defense in mine for carry.  I've shot 150 rounds of this in the gun to make sure it runs OK, which it does.  I think it was the only "defense" round in stock when I bought the gun and ammo, so its what I had and use.  For practice, I've only run Winchester White Box and some Sellior and Beloit (sp) in it.  Not sure on bullet weight, but both have shot fine.

About the only ammo I have not run through my 238 is the steel cased Russian stuff (I wont run this stuff through my higher quality guns) and any Buffalo Bore (just havent picked any up yet). Only issues I have had is with PMC, which could have been due to me slacking on maintenance and the ammo being a touch light and cooler.
ETA: I carry Gold Dots and use Blazer as my range ammo.

Either CorBon DPX or FMJ. I don't trust any other HP to penetrate sufficiently (and I'm not 100% about the DPX).
Tomac

I have shot hundreds of Federal, Winchester, Hornady, Magtech through both my wife's and my P238s with no issues. I carry Hornady CD, but shoot a lot of Federal and Magtech. I reload 380 using a 100gr home cast bullet which shoot great out of my LCP, but haven't had the chance to shoot these loads out of the P238s yet. But the wife sure did make me a pile of brass for reloading. We e went through about 500 rounds a few weekends ago to break them in. I still have about 100 more empty cases to reload.

I would seriously follow the guidelines on using the grease and not oil on the rails. They do seem to dry out pretty fast if you use oil. Never had a ftf/fte or any other malfunction, but I do notice when they start to get dry. Great little guns in my opinion, great features out of the box. Only thing I have changed on ours has been swapping out the factory grips with VZ ETCs.

Couple of pics...