Caliber to cut my teeth on...

[oldpink]

When I first started reloading, I dove straight into .30-06.
Never had a problem other than discovering that solid copper bullets need their powder charge reduced a bit.
As the others have mentioned, straight walled handgun cartridges are easier to load, especially if you have carbide dies.
The only things I would point out are use the proper type of crimp (taper crimp for autos, roll crimp for revolvers), and it's best to roll crimp separately from seating to prevent buckling the case.
Taper crimping seems (at least for me) to be okay while seating, though.
Also, be sure to get your primers seated just slightly below flush.
Good luck, and enjoy your new hobby.
It's really satisfying making your own ammo.

 

[VERT]

Or the 230 RN. I bought a case of each & both work ok, but I have the occasional ftf with the LWSC (1 of 100 kind of thing).

Hmmm.... I have had that problem. 1) check your OAL. Too long a cartridge hangs up my Smith. 2) remove the shock buff and/or check your recoil spring.

 

[HamYankee]

45 will be what I start out with.

 

[8th SPS USAF]

45acp first to get your reloading skills, then 9mm and get a buddy who loads rifle to give you help when you want to go to rifle.

 

[woodsie57]

When you tire of chasing/ losing brass, get a good 357 revolver and some cast bullets

 

[oldpink]

When you tire of chasing/ losing brass, get a good 357 revolver and some cast bullets

I love revolvers, but you are narrowing yours and others' horizons far too much.
BC Sap Brass Catcher for Semi Auto Pistols by Custom Cast USA BC Sap | eBay

 

[woodsie57]

Yeah, that's a solution,as is a tarp on the ground. Both are ways off addressing the basic design flaw of semi-auto pistols where reloading is concerned.

 

[Iroquois]

Well, this would be a good excuse as any to buy a revolver.
I learned on a single stage and 38 special. Longer case , no head space
Issue, lots of powders to choose from. You don't know pain till you shear
Off a little bit of your index finger between a stubby little 9mm and the
Bottom of a sizing die ,using a press that generates 2400 pounds of
Force.....yeah, good times.

 

[throttletony]

eithet .45 or 9mm as long as you're NOT using a low-volume (compact) powder.
To avoid double-charges