I love these discussions;

It does not matter really what you use as much as it matters how well you can shoot it under extreme pressure.

What I am saying test your skills under pressure on the range with your weapon of choice.

Bottom line is if you are 12" wide of the target even the 12 Ga will not be effective.

Another important consideration is the recognizing of a dangerous situation and having the tacticle advantage of NOT being surprized.

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.

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 carry my Kimber 10mm often while salmon fishing for Bear protection or skinning a moose.

I carry 200gr Hardcast at 1250 FPS factory loads in it........made for thick skull or shoulder blade of a Bear.

The 10mm in a Auto is very convenient to carry but does not equal my SW 629 in 44 Mag. which is a better bear protection round.

I normally have a 12ga Shotgun with Brenneke Slugs close by on my daypack my preferred Bear protection weapon.

Zero and practice at 10 to 15 yards or where ever your cutoff comfort zone is with Bear.

Quote from: Alaska on March 26 2017 01:17:19 PM MDT
I carry my Kimber 10mm often while salmon fishing for Bear protection or skinning a moose.

I carry 200gr Hardcast at 1250 FPS factory loads in it........made for thick skull or shoulder blade of a Bear.

The 10mm in a Auto is very convenient to carry but does not equal my SW 629 in 44 Mag. which is a better bear protection round.

I normally have a 12ga Shotgun with Brenneke Slugs close by on my daypack my preferred Bear protection weapon.

Zero and practice at 10 to 15 yards or where ever your cutoff comfort zone is with Bear.

Welcome and thank you for your input Alaska! What is the closest you have encountered a grizzly or a brown bear and what was its attitude?

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.

SBR in 458 SOCOM 3-point sling loaded with 460 grain hard cast boolits. maybe one the new Mossberg Shockwave 12 GA with brenneke slugs.

Quote from: DM1906 on April 28 2016 12:24:48 PM MDT
As said, it all depends on the bear. 10mm against a brown bear is nothing more than a deterrent, regardless of the cartridge. Few handguns, short of the big magnums, are better than spray. Black bear are different and size matters (the bear's and the bullets). .40SW with 180 gr. Black Talon can dispatch 350-ish pound black bear. Done it twice out of necessity. 3 rounds in the neck and shoulder (Mozambique-like, if you will). Larger than that, I dunno. .41 and .44 Magnum will stop the 500+ pounders (been there, done that). The 10mm is NOT comparable to .41M, I don't care what anyone says (10mm gets about 1/2 way to 265 gr. @ 1430 FPS). The 180 gr. Underwood you have will about as effective as any 10mm for defensive shooting black bear. They'll penetrate as well as any hardcast, and the bullet won't matter if you miss vitals. Also consider, if you haven't shot that ammo in your pistol before, it may not run. Some pistols don't like the big, flat-nose bullets. Use a pistol to buy time to get the 12 ga, which is what you need. Time. It helps if you have a plan, but the bear has no intention to play by your plan. Chances are, you won't see a bear. If you do, he'll likely scatter before you can break leather. Also, having a yappy dog around helps, both as an alarm, and a deterrent.

Baloney.  10mm with the right ammo kills Grizzlies dead.  Google handgun bear defense 93 cases. 

Welcome Alaska, my preferred protection would also be a 12 gauge, alternating slugs and 00 buckshot, using my favorite HEVI-Shot Dead Coyote's 9  pea sized pellets; That with a high cap 10 on my chest or hip, and a high level of situational awareness, you would be safer than most 😊

https://www.ammoland.com/2019/10/alaskans-stop-grizzly-bear-charge-with-glock-10mm-on-elmendorf-richardson/#axzz6mMzC7XO1

Quote from: fernpatch on April 28 2016 03:19:57 AM MDT
First I don't know if this is the best section to post this question as it does not directly involve hunting.

I am going to visit a friend this weekend to help cut and split a number of trees down on his property and he called today to let me know that his neighbor spotted a bear today. I am wondering what 10mm load would make for good bear medicine should a critter decide that I look tasty while cutting and splitting firewood.

My normal carry load is underwood 180gr gold dots. I also have on hand some underwood 180gr FMJ loads.

Would either of these be appropriate or should I:

1) Scour the local shops hoping to find a different load.

2) Be resigned to keep my 12ga close by with 3 inch slugs

Thanks in advance for any and all replies.

hornady and speer makes a (or used to) make a semi jacketed round nose flat point, they will penetrate deeply if you cannot find those I'd suggest the lehigh defense 140 grain extreme penetrators  either of those loaded will stop a bear, including a brown bear ......

Quote from: sqlbullet on April 28 2016 02:49:52 PM MDT

Quote from: fernpatch on April 28 2016 02:35:53 PM MDT
best area to target to stop an angry bear?

Knees.

Once you shoot your friend in the knees he won't be able to run and the bear will stop at him.

LOL, thank you for that, made my Friday. Have heard it a hundred times and it never gets old.

     Although an old thread we enjoyed this discussion.

    Wife and I worked several Fall seasons in a ride-in camp in the Wyoming Range S. of Jackson and West of Bondurant. We kept one of our 5" model 29s stoked with 320gr. LBTs close to hand all the time but never had to use it; thankfully. There were Griz in the area but they were seldom a problem for the outfitters in the area. Think having our Heeler dog around camp helped keep the bears at a distance also. We have found the .44mag tougher to shoot well in DA mode as we've gotten older, hence our switch to the 10MM in the 1911 and our presence here. Lots of good info on this site.
     Here in the Alleghenies we have only black bears and our son loves chasing them with hounds. His new bear gun is the DW Bruin in 10MM launching 200gr. WFNGC cast bullets at 1262fps. 

Well the thing about bears & mountain lions is to be very watchful, as they could sneak up on you.  You are in their backyard and they see you as food or threat!
Bears use their sense of smell and can be attracted to many different smells especially foods. 
They will be very protective of their young even older cubs.
Heavy duty large canisters of Bear spray can help deter an attack somewhat, but they can be very aggressive!
You can not have too much gun, Hard Cast will be better to bust bones and deep penetration.

I live in Grizz country the 10mm load of choice is 200gr hard cast around here. As stated above shot placement is critical so a load you can shoot the best in my thoughts is better than a hot load that you can?t.