You have one shot from a gun firing either.  You have your choice in any weight offered in either with any store bought load/bullet.
You leg is hurt and you're sitting with your back against a tree.  There is a lion approaching, just one, and you have one
shot. If you don't take him down you're dead.  Do you go with the heavier and slower 300BLK or do you "heavy up" in
.223/5.55 like somewhere in 69-77grain-ville and hope for some static-shock/penetration with the still very high velocity (but lighter round than any 300 BLK)?
Or do you go light with 300 BO like 110 with TSX and hope for controlled expansion?  Or do you go heavier super sonic 300BO like 150 and hope
1800fps + mass will take him?  These might all work in their own way but I'm curious more about the theory.

I'm curious about this situation.  If this were a bear or larger animal the answer would clearly be some variant of 300 BO but a lion
is smaller but still a large animal. Highest muzzle energy of either caliber would certainly be the lighter weight in 223/556 but muzzle energy
doesn't always tell he true story.  In the BO you don't have  velocity anywhere near .308/06 or even 30-30 for that matter.  And the idea of a
50-55g @ 3300+ won't work against large heavy muscle/coated animals like it will against 2-leggers as the bullet will disintegrate probably w/o
sufficient penetration.

Two Cents please!

High speed, low drag. 5.56

If I could choose, it would be Barnes .300 Blackout 110gr TAC-TX. More energy=more better. *ETA 2*: This assumes SBR length barrels. BLK does better in short barrels than 5.56. I would realistically have either an 11.5" 5.56 or a 10.5" BLK in any situation where a lion would be present so that prejudices my choice.

I also hunt whitetails with this BLK round and know it's effects first hand. If I HAD to use 5.56, I would go with a 77gr TMK, but I think the BLK load would be better.

ETA: This of course also assumes proper shot placement. If you don't hit the boiler room with either, you have a few seconds left to live.

300 Black 120grain Nosler.
and a fresh pair of shorts for 'afterwards'.

Neither. I am guess in you are referring to a mountain lion very tough, but not the King of the jungle lion.
Energy is everything. Speed isn't an end all.
Energy moves things, drives things, and breaks things.
I'm not a 300 BLK fan so the heavy gr 5.56. 75 gr Gold Dot or the like. Good penetration and expansion. A heavy Copper like a Barnes would be on the menu as well.  
YMMV

110gr wet expanding blk out of an 8.5-10.5" barrel.

I'm confused.

If a 300 is the "clear" answer of the two choices for an animal larger than a lion, then it would be the clear answer for a lion as well. No?




And this is incorrect.

I'd wait until he's inside 25 yards then I'd put a 220gr subsonic 300 through his brain.

I would take the much smaller and lighter bullet hoping it would do more damage...oh wait no I wouldn't the clear answer is the 300BLK which will cause a lot more damage than a smaller round. The 300BLK has a much better chance of penetrating bone and with its larger caliber and greater expansion creates a larger permanent wound cavity. It will also penetrate deeper into the cat getting to more vitals than the .223 round can.

556 with 24 inch barrel. Now if you stipulated that I must have a 10 inch or shorter barrel then it would be 300 blackout. 

Given that i have a 8.5" blackout...that critter would be eating Barnes copper. However i wouldn't be in a situation to battle a lion without my .458 SOCOM.

300 blk with 120 TAC-X

6.5 Grendel

This is how ridiculous the Grendel people have become. The question was not between Grendel, .223, 300BLK.

So, the rational thought was to interject with a caliber that is very close to what the others offer instead of say a 7mm mag, 300 win mag, 458 socom, 500 Nitro express or even the 50BMG. Some of which would probably split the cat in half guaranteeing that you don't become dinner.

It is just sad at the lack of imagination and the religious fervor that the grendel guys interject into places that they weren't asked and then come up with a caliber that not a single hunter in their right mind would take to hunt creatures that can eat you.

I'd rather have a full power rifle caliber like a 30-06 or something. But between those two intermediate rifle calibers I'd go with 300BLK since it's still a 30 caliber projectile and will penetrate better. It's like if I go hog hunting I'm using 300BLK over my 5.56mm guns. 

Adult Lions weigh on average: males 420 lbs, females 280 lbs. I'd choose a 300 BO with 110gr Barnes Tac-Tx given your scenario. Hits hard, penetrates better and opens bigger.

If an adult Lion snuck up on me in the woods, I would greatly prefer this:

METAL BUMP  

for me, it would not matter because i'd use the last round on myself.

i really dont see either round stopping a saharan lion fast enough to keep him from still biting your head off.


wouldnt a 77 gr tsx do a decent job of breaking skull bone and doing enough damage?

seems like a horse and horse between these two rounds.

Same here.
I've seen what it does to whitetails and hogs out of an 8" barrel.

say "What" again.....

For 5.56, it would either be the 69gr tmk or the 77gr tmk

For 300blk, same thing. Either the 110gr Barnes vor-tx or the 120gr Barnes vor-tx.

I hunt mainly with the 110gr vor-tx, but have used all 4. From what I understand, it's splitting hairs on all 4 except for when it comes to the 69 vs the 77gr tmk in a sbr.

If someone knows better on the differences between the 4 (69v77 and 110v120), I would love to learn something.

Don't have the 300 so I'd be using 5.56, BH 70gr GMX load and praying.

I'd save my one shot for something I could eat and take this sucker down with choke hold or knife if I was feeling lazy.