I'm new to the 10mm cartridge, but so far I like my Gen 3 G20sf.

What are the general thoughts on bullet weight for this cartridge? Should I go heavier or lighter?

It depends on what you are wanting to do, hunting, self defense, target play.

In general 155 to 180 are used for self defense (light clothing light bullet heavy clothing heavier bullets), can be useful for some hunting too.  However 200 grain can penetrate deeply even if bone is encountered.  Some like the 200 and 220 for hog hunting, they are tougher animals.

Target anything will work if loaded right.

Like Shadow  mentioned,  155s to 180s for defense purposes. I'd go 165s carry rounds.

I favor heavy bullets...

But, 135 grain loads can deliver some devastating wounds with less recoil than full bore 180 grain or 200 grain loads.  Full bore 135 grain loads will generate a full 1.5lbs less free recoil than a full bore 180 grain load in the same gun.

For my 10mm Kimber Eclipse carry-gun, I load several different bullet weights alternating in each magazine: 150gr, 180gr, and 200gr Nosler DoubleTaps, specifically.  However, I've just ordered a few boxes of 135gr Nosler Doubletaps, and I might decide to add those into the alternation. I do the same kind of thing in my .44mag S&W69 carry-gun when the bears are asleep: 185gr, 200gr, and 240gr JHP's.  But when the bears are awake, I load all 240gr JHP's, because I think that's the best compromise for both 2 and 4-legged predators.

Is the question for purchased ammo OR bullets for reloading ?
If for reloading and for plinking/general range use,the most economical are the light projectiles.

I'm with Pacapcop....165 grains will do ya.

Heavier bullets usually penetrate deeper.

Lighter bullets have a flatter trajectory.

180/200 for me. 

Thanks for the input. I'm thinking hot and heavy is the way to go for 10mm. I got some 180 grain Underwood xtp coming in with a 1300 fps. I don't think going to heavy on the bullet would benefit beyond that.

Mine's an Underwood 10mm 200 XTP with 1250 fps.

I like the 165's.

I feel they're a good compromise between speed and energy, with less umph on the pistol.  Heavier bullets tend to rock the pistol around more at 10mm loads.

My 165's are moving at 1256 fps with a more than decent energy level of 578 ft/lbs.  These have a bit more flip than a 45 acp, but no where near a 44 mag.  To each his own.

I like the 165 for the 40sw while I like 180-200 for 10mm. One time I bought two 20 rnd boxes of Underwood 40sw 155 XTP rated at 1300 fps. I shot a box and they are hot!

Quote from: Olgo on September 26 2016 07:39:32 PM MDT
I like the 165 for the 40sw while I like 180-200 for 10mm. One time I bought two 20 rnd boxes of Underwood 40sw 155 XTP rated at 1300 fps. I shot a box and they are hot!

I am pretty sure the 155 grain XTP's are running at 1500 fps.

For the 10mm it is 1500 fps but mine's a 40sw which is 1300 fps.