Not to rain on the parade, but my best friend carried a Glock 33 for several months. He eventually sold it because even ball ammo was pretty pricey and the selection was very poor, esp carry loads. And this was in a good sized city, not a rural town.
Let's go over this well trodden ground again.... the 357 sig is a 21st century caliber. The best way to find ammo for it is to use a 21st century method - the Internet!!!! If you have computer skills/ access ( which you must to post here ) & a credit card, the 357 Sig possibilities are substantial. I have shot 54 different loadings and still have a ways to go if I want to try them all ... here's my list:
1.) American Eagle - 125g - FMJ F
**2.) CCI Speer Blazer - 125g - TMJ F
3.) CCI Speer Lawman -125g - TMJ F
4.) CCI Speer Gold Dot - 125g - GDHP F
5.) Collins Cartridge Co. - 125g - FMJ
6.) Corbon - 115g - JHP F
7.) Corbon - 125g - JHP F
8.) Corbon DPX- 125g - DPX
9.) Corbon Pow'R Ball - 100gr - PB
**10.) Corbon BeeSafe - 91g - BS F
11.) CNC Cartridge - 124g - FMJ F
12.) CNC Cartridge - 124g - JHP F
13.) CNC Cartridge - 102g golden sabre - JHP F
14.) DFA - 85g - Nylon ( lead free )
15.) Double Tap - 125g - JHP F
16.) Double Tap - 125g - FMJ
17.) Double Tap - 115g - JHP
18.) Double Tap - 147g - JHP
19.) Federal - 125g - FMJ F
20.) Federal - 125g - JHP F
**21.) Federal - 150g - JHP F
22.) Fiocchi - 124g - FMJ
23.) Georgia Arms - 125g - FMJ F
24.) Georgia Arms - 125g - GDHP
25.) Hornady - 124g - JHP F
26.) Hornady - 147g - JHP F
**27.) Lancer Custom - 125g - FMJ F
**28.) Lancer Custom - 125g - XTP
**29.) Lancer Custom - 125g - JHP
30.) Maine Cartridge Company - 147g - JHP F
31.) Master Cartridge - 125g - FMJ (RL) F
32.) PMC - 124g - FMJ F
33.) PMC Starfire - 125g - JHP F
34.) Precision Ammunition - 125g - JHP F
**35.) Pro-Load - 125g - JHP F
36.) Reeds's Ammo & Research - 90g - XTP
37.) Reeds's Ammo & Research - 115g - XTP
38.) Reeds's Ammo & Research - 124g - XTP
39.) Reeds's Ammo & Research - 147g - XTP
40.) Reed's Ammo & research - 124g - Gold Sabre
41.) Remington - 125g - JHP F
**42.) Remington Gold Sabre - 125g - BJHP
43.) Sellier& Belliot - 140g - FMJ F
**44.) Triton - 115g - JHP
**45.) Triton - 125g - JHP
**46.) Triton - 135g - JHP F
47.) Ultramax - 125g - FMJ (RL)* F
48.) UMC - 125g - FMJ F
49.) UMC - 125g - JHP F
50.) Wagner Acuswage - 125g - TMJ
51.) Winchester - 125g - FMJ F
52.) Winchester - 125g - JHP F
53.) Winchester - WinClean - 125g - BEB
54.) Winchester Ranger - 125g - SXT
** - no longer manufactured
Within this list is a variety of good carry rounds:
Gold Dot
Double Tap
Hornady
Starfire
Federal
Corbon DPX
& I recommend Reed's and CNC as very good ammo!
Buffalo Bore is also now making loads!
There is practice ammo that is not much price difference than a .40
Georgia Arms
master Cartridge
Wagner Acuswage
I have heard good things about Precision Cartridge although I have not personally tried any ( Yet )
Lawman, American Eagle, Fiocchi, Winchester are a little pricier but all good stuff.....
By the way, I really really like my G31. I have used it to shoot GSSF matchs and one IDPA match. Never ceases to amaze me how consistantly accurate it is.....