45 ACP on Brown Bear.????

Since I have not had to really make a plan for being in Grizzly country, this thread has become somewhat of an obsession! This will be the 4th time I re read through... every day something comes out that redefines something from the past.

I know I never imagined a 3.5 liter gas motor that could keep up with a 7.3 diesel in terms of towing capacity, but we have that today.

As for bullets... we used to have choices that were the weight of the bullets... 30-06 had 120, 150, 180, and 220 grain bullets... 168 if you shot “match bullets”... now we have dozens in each weight class...

Guess my point is in today’s world, to answer the question that started this... absolutely a 45 ACP be used for defense against a bear... is it the best choice... if we went on this, all of us would be reloading for the same rifle caliber to shoot an Elk.

Today’s ammunition is so far removed from what it was even just 10 years ago.

Not poking at anyone, but one of my decisions to post again was hearing some say absolutely not for the 45 but a 40 cal is fine... the 40 cal ballistically is an attempt to make full house original 10 mm loads work in smaller guns for smaller hands with controllability that everyone in law enforcement could handle (lot more to this but not going to bore y’all... look into the 10mm or fbi Miami shootout)...

Longer story shortened... 40 S&W barely duplicates 45 ACP ballistics in most cases, but side by side, a 45 ACP can be pushed with a heavier bullet faster.

It’s not so much a choice about the caliber but the bullet choice. If you can shoot something like the 255 gr Buffalo bore hard cast in your 45, you pretty much have the same as the 44 mag, 454, 41 mag at the range we are talking about.

I think the problem is people think about hollow points... hollow points for hunting in a handgun are not a good idea in my opinion... hollow points are for helping keep a handgun bullet from over penetrating in an environment that has other people... was very interesting reading about actual use against bears from everything from 9mm to 454... surprisingly the only caliber that actually “failed” was 357... I think it was because the bear was not hit squarely, but anyway.

Additionally... lots of people say that a 12ga slug is the best and that only rifles 338 or larger... well I did some testing today... my 870 ish 30-06 with even just 180 grain partitions was a lot easier to shoot accurately than a Mossberg 509 with slugs. I am sure both would work well if needed... just don’t understand the need for a 338.

If... IF... I was going on a hunt specifically for Grizzle I get the 338 recommendation... this post is about the effectiveness of the 45ACP...

Has a documented track record and with the right bullet... maybe even just fmj I wouldn’t feel undergunned in terms of it being part of my protection plan in Grizworld. I would want something high cap though.
 
First of all, what on the heck is a guide doing carrying a 9mm pea shooter in the woods hunting Brown Bear? He must be a complete fool in my opinion. The odds of him killing one are extremely rare, and IF he doesn't which has a very HIGH probability means he just gonna **** him off and charge him. Then what is he gonna do, launch some MORE 124gr 9mm bullets at him an hope he stops and goes away?!! Lets apply ration, reason, and a sliver of logic.
He was actually guiding fishermen. But after reading a number of articles on him guiding hunters, and listening to other guides when I lived in Alaska, and having less than ideal results with mid-big bore rifles by US standards, only carrying a 9mm was something that left some scratching their heads.
 
45 acp +P is close to 10mm
I don't disagree that the .45 ACP is a great cartridge, I used one for many years on and off the job, it's still my go-to caliber for 90% of anything that goes bump in the night. Today my .45 ACP carried with Underwood +P 200gr solid monolithic Xtreme penetrator or Remingtons 230gr Golden Saber HP But... as big Bear goes I take my G20SF with Underwood 200gr +P solid monolithic Xtreme penetrator, I digress. I think the real answer here, between the .45 caliber and the 10mm (pistols) because velocity matters, is the sectional density with each of the bullets in the same weight, yet at a different or the same velocity, e.g. I can't push a 200gr .45 ACP +P faster then I can a 10mm +P
Small diameter, same weight, at the same or high velocity in this case the 10mm SDs small diameter will always penetrate better, which I believe has been demonstrated many times. So the key references may well be sectional density in the conversation. It can be deceiving because the .45 caliber with heavy bullets can have higher SDs... but... from a .45 ACP with a much, much low velocity... which is kinda is self-defeating in the long run. So trying to stay with; apples and apples, I'd think the 10mm has the edge in the ballistic penetration, by quite a bit and then some. I used solid monolithic because of explanation again will change the outcome on both the .45 cal and 10mm bullet choice, as to the depth of penetration.


Sectional Density is the ratio of an object's mass to its cross-sectional area with respect to a given axis. It conveys how well an object's mass is distributed to overcome resistance along that axis.


.45 caliber (.451-.452")

  • 185 grain, SD .130 ****
  • 200 grain, SD .140 ****
  • 225 grain, SD .158
  • 230 grain, SD .162
  • 250 grain, SD .175
  • 260 grain, SD .183
  • 300 grain, SD .210

.40 / 10mm caliber (.400")

  • 155 grain, SD .138
  • 165 grain, SD .147
  • 180 grain, SD .161 ****
  • 200 grain, SD .179 ****
As always just my 0.2 Cheers.
 
Loaded to the same pressure as a 10mm in a modern hand gun, I think the 45acp performance would be superior in all regards except mag capacity and maybe recoil. I have never loaded a 45ACP to 37,500 psi, so just say'n.
A 38k chamber pressure .45 ACP is called a .460 Rowland. I converted my Glock 21 to one. Bought an aftermarket barrel and had a .45 acp reamer run a smidge deeper to chamber .460 cases. Then added a comp/brake and some heavier springs. Mine will send 255 gr hard cast Undaerwood ammo at almost 1400 fps.
Had my first bear encounter a little over a week ago while hiking some back country with my wife. Glad I had my pistol on my chest, that 125 lb dude sure looked menacing! 😂
 
Years ago - in upstate Michigan - a hunter killed a Big Brown Bear - which had at least half a dozen .45 bullets in it. The guy shooting the .45 was never found. A .45 is deadly on 200 lb humans - but hardly noticeable on a 700 Pound Brown Bear/Griz - who also has a thick fur coat.
Brown bear in Michigan ? Probably a brown colored black bear. This story I haven't heard of in Michigan.
 
Since I have not had to really make a plan for being in Grizzly country, this thread has become somewhat of an obsession! This will be the 4th time I re read through... every day something comes out that redefines something from the past.

I know I never imagined a 3.5 liter gas motor that could keep up with a 7.3 diesel in terms of towing capacity, but we have that today.

As for bullets... we used to have choices that were the weight of the bullets... 30-06 had 120, 150, 180, and 220 grain bullets... 168 if you shot “match bullets”... now we have dozens in each weight class...

Guess my point is in today’s world, to answer the question that started this... absolutely a 45 ACP be used for defense against a bear... is it the best choice... if we went on this, all of us would be reloading for the same rifle caliber to shoot an Elk.

Today’s ammunition is so far removed from what it was even just 10 years ago.

Not poking at anyone, but one of my decisions to post again was hearing some say absolutely not for the 45 but a 40 cal is fine... the 40 cal ballistically is an attempt to make full house original 10 mm loads work in smaller guns for smaller hands with controllability that everyone in law enforcement could handle (lot more to this but not going to bore y’all... look into the 10mm or fbi Miami shootout)...

Longer story shortened... 40 S&W barely duplicates 45 ACP ballistics in most cases, but side by side, a 45 ACP can be pushed with a heavier bullet faster.

It’s not so much a choice about the caliber but the bullet choice. If you can shoot something like the 255 gr Buffalo bore hard cast in your 45, you pretty much have the same as the 44 mag, 454, 41 mag at the range we are talking about.

I think the problem is people think about hollow points... hollow points for hunting in a handgun are not a good idea in my opinion... hollow points are for helping keep a handgun bullet from over penetrating in an environment that has other people... was very interesting reading about actual use against bears from everything from 9mm to 454... surprisingly the only caliber that actually “failed” was 357... I think it was because the bear was not hit squarely, but anyway.

Additionally... lots of people say that a 12ga slug is the best and that only rifles 338 or larger... well I did some testing today... my 870 ish 30-06 with even just 180 grain partitions was a lot easier to shoot accurately than a Mossberg 509 with slugs. I am sure both would work well if needed... just don’t understand the need for a 338.

If... IF... I was going on a hunt specifically for Grizzle I get the 338 recommendation... this post is about the effectiveness of the 45ACP...

Has a documented track record and with the right bullet... maybe even just fmj I wouldn’t feel undergunned in terms of it being part of my protection plan in Grizworld. I would want something high cap though.
Technology is amazing. While your imagining that the 3.5 gas engine vs the 7.3 diesel in towing is comparable is very unrealistic, the cartridge performance and bullet construction is not. This discussion on the 45 vs Brown bear is a personal choice. Not that I'm saying I'd use a 9mm for defense against a brown bear but it's happened and succeeded in killing them in charges. The 45 will achieve the same with proper bullets and loads. Accuracy is the most important part. Very controversial of course on which defense pistol but confidence and the right load makes the most difference given the cartridge can penetrate heavy bone. I'd say number of rounds on target is important so practice will make a big difference also in making that happen. Use the biggest pistol cartridge you can accurately shoot.
 
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