Having head shot (almost a contact shot) inside a cook tent a black bear with a 444 Marlin, I can tell you that when you are that close, any FMJ or hardcast solid will work.
After that experience, it's at least a 44 Mag or a 12ga with slugs as a minimum for me in bear country. 308Win or bigger rifle is preferred.

Black bears when riled are different than Browns or Grizzlies, you will be a fight to the death. Almost like little man syndrome of the animal kingdom.

I have been testing my new 21" heavy barreled Howa Mini in 6.5 Grendel. It's a sub .75 MOA shooter with Hornady A-max 123gr ammo. I will be doing load development with this rifle using Hornady brass and 95-100gr bullets for coyotes and prairie dogs.

Further testing is showing it to be a closer to a .60 moa gun with factory ammo. I'm now working up some 95gr V-max load for it.

Having shot a Blue Wildebeest with a Glock 20 and 180gr XTP's, I would not recommend that load for thick skinned game or bears.
To much expansion and insufficient penetration, find a suitable hard cast of FMJ flat point bullet that feeds well in your pistol.

Any idea on the time line for this build?

TRADED!

I'm going in a different direction for my hunting handgun and this one is on the market: G20SF, box, papers, stippled side panels, suppressor sights, two magazines, 3.5lb connector and set up by one of the Brownells staff gunsmiths designed RMR cuts then the slide was finished in CeraKoat Burnt Bronze by Controlled Chaos Arms.

$1025 OBO shipped to your FFL holder.

Quote from: darkstar on September 19 2016 05:26:25 PM MDT
I have a box of underwood 220gr hardcast @ an advertised 1,200fps i would think that this load would penetrate like crazy. A lot of guys who shoot hard cast in rifle's (think 38-55 and such carttidges) say that upping the velocity past 1,200fps or so does not aid in penetration, sometimes the opposite. I think Buffalo Bore has a 230gr hard cast also. Most people carry these loads for defense against bears when bumming around in the woods, would love to see what kind of penetration they would have on the big ornery stuff.

There have been a couple of published articles regarding penetration and velocity. If you are in the 1000-1300fps range, with properly constructed and heavy for caliber bullets, that will provide for the deepest penetration. That is one of the reasons that Garret makes the reduced velocity Defender load of 44mag Hammerhead cartridges.Those are his 300+ grain 44 Mags that are only loaded to 1050fps, vs 1350fps for the Hammerheads. Much easier to shoot, yet they still equal the penetration of the faster rounds. The faster bullets are just effective at longer range on Elk and Moose, but have been no better at stopping bear attacks with head shots in the real world.

I've shot a couple of hogs with 180gr XTP's and one Blue Wildebeest. The Federal TBBC's will give better penetration than any other non-hard cast bullet in the 10mm, you can shoot them just about anywhere in the front half of the body and you will be just fine.

The_Shadow is right on, it's almost impossible to go wrong with the RCBS Rockchucker starter kit. I'm still using mine as my primary press after nearly 22 years and over 70,000 rounds from 9mm pistol to 416RemMag. I have yet to find a scale worth the cost to replace the RCBS 5-0-5 that came with the kit. 

Quote from: sqlbullet on September 29 2016 08:40:08 AM MDT
I know this is a 10mm question, but laws like that make me wanna show how stupid they are.  Get a 460 S&W and plug a deer.  Post far and wide how well this "pistol" cartridge does with only double the energy of a 30-30 rifle.

That said, RMWxtreme is the best answer to this question.

This effort is part of my building a case to remove the shotgun slug/handgun only limitations in Iowa. Sometimes you have to prove total stupidity in a decision to make a point.

Guys:

I have been a lurker here for sometime and have built up an RMR equipped G20SF for a hunting pistol. But it's still a bit large for my hands. The AR15 pistol seems like a better option for me for hunting, as rifles are not legal for deer in Iowa, but any straight wall pistol is, go figure.

What is the best off the shelf upper choice? I already have a Glock magazine AR15 pistol lower ready to go.

Thanks in advance!

Quote from: Blades on August 29 2016 08:31:35 AM MDT

Quote from: Rojo27 on August 29 2016 04:24:39 AM MDT
Hiker used HPR 180gr jhp...

I have some HPR 200gr JHP's in my two extra magazines(Critical Duty 175 gr in my Glock 29 and the magazine in my back pocket). I like them but am concerned the short barrel of the G29 may keep them from expanding.
The black bears that show up around here try to run. Usually up a tree.

Penetration on a bear is more important than expansion, your G29 should be just fine.

They are nearly bullet proof. For hunting, go with the LED version so you can see the sights better. If you use the dual illuminated version, try the 12MOA Triangle, it's the easiest to pick up of the non-led versions.

Quote from: schtoolee on January 05 2014 04:07:01 PM MST
The Olympic is blowback, chances are the other one is too.

Thanks!

Are they gas or blowback operated?

Bullet selection with the 10MM is critically important. I used my Glock 20 in 2004 to put the finishing shot into a Blue Wildebeest. It was loaded with 200gr XTP's. The first shot hit a rib and deflected off and under the skin, traveling about 17" from the point where it made the 90 degree turn. 

I would not used that bullet again, but instead would go with a 200gr hardcast gas checked semi-wadcutter. Something heavier with a higher sectional density would be even better.