What AR15 caliber would be best for bear at 300 yrds max

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dan158

New member
I would like to build a deer and black bear AR 15.. Max be 300 but more realistic max would be 150.. I was thinking about 6.5 or the 6.8..

I seen on bear whisperer he has taken a couple Black bears with the 6.8 is why I was leaning that way..

Or would a 6 or 6.5x 6.8??

What would other suggestions be strictly on the AR15 platform with 22 inch barrel..

Also bullet choice for caliber chosen..


I Don't want to build a 10 because of weight.. Thank you.. Dan
 
Dan, if you are concerned with weight I would opt for the larger bore. 6.8, 25 DTI, or even a 264 LBC. You can keep your barrel length down, and when you have a shorter barrel, light profiles still give you great accuracy.

Edited to add: in the 6.5 I would use the 100 grain Nosler partition. In the .25 I would either use the Sierra 90 grain Game King or 100 grain Nosler Partition.
 
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My understanding is the 264lbc is the same as a 6.5 Grendel.. Would I get more performance out of the 264??

What is a big bore 6.8??



This is what I am thinking when seen both those mentioned.. A 1000lbs of feathers or a 1000lbs of rocks?..


Thank you... Dan
 
Originally Posted By: dan158My understanding is the 264lbc is the same as a 6.5 Grendel.. Would I get more performance out of the 264??

What is a big bore 6.8??



This is what I am thinking when seen both those mentioned.. A 1000lbs of feathers or a 1000lbs of rocks?..


Thank you... Dan

Dan, what I said was if you are concerned with weight, then go for the larger bore 6.8. Meaning that the 6.8 was actually designed around a short barrel. The 6.8 necked down to 6mm need far more barrel to burn the same volume of powder.

The 264 LBC is, for all intents and purposes, the same as a 6.5 Grendel. It has slight differences in the throat, but uses the same dies, load-data and loaded ammunition. It is my opinion that the throat in the LBC is an improvement over the Grendel, and there is no copyright infringements with the LBC.

I’m not sure what you are referring to with the feathers/rocks coment.
 
Originally Posted By: dtech
dan158 said:
I’m not sure what you are referring to with the feathers/rocks coment.

A big bore 6.8 is still a 6.8 bore. The bore being the same diameter.. And a 264 is the same as a 6.5 just a different throat correct ? To shoot different size bullets as to not loose case capacity when seating longer bullets deeper in the case..

Is that correct.. Dan
Click to expand...
 
My vote goes for the 6.8
I built mine with the intent to use it for black bears over bait, coyotes, and my daughter to use for deer hunting.
I haven't shot a bear with it yet, but my daughter just shot her first deer with it last week and it worked perfectly (120gr Hornady SST)
I love that it was designed for shorter barrels (mines 18"), plenty of factory ammo available, and fits in an AR platform rifle.
I was so pleased with the way it performed on that deer I'm tossing around the idea of building another.
 
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Dan, I probably just didn’t use correct punctuation. I wasn’t making a distinction between a 6.8 and a 6.8 “big bore”. Again, the point I was trying to make was: If weight is a concern, the larger bore 6.8 (as compared to a 6mm bore) will allow you a much lighter rifle.

There are several reasons that the larger bore is a better fit for the hunting you described:

1) If you take a line of cartridges, like the ones based off of the .308 Winchester, Or the DTI line, as you go up in bore diameter, the energy goes up as well. Pressure is the limiting factor. The same pressure applied to a larger surface area (larger diameter bullet) the more force you get out of it.

2) As the bore diameter goes up in a cartridge family, the length of barrel necessary to burn the powder goes down.

3) Along with diminishing need for barrel-length comes the ability to shorten the gas-system without compromising performance, or reliability. The big up-side to a shorter gas-system is a lighter barrel.

Keep in mind: All things being equal, barrel rigidity is what gives you accuracy. Barrel rigidity can come two ways: Large diameter, or short. In other words, the longer the barrel, the heavier it has to be to retain accuracy. When you get down to an 18” barrel, it doesn’t have to have a large diameter to be just as rigid and accurate as a MUCH heavier 22” barrel.

I talk to folks all the time that stil have the misconception that longer barrels are more accurate. That notion comes from the days of iron-sights. The longer sight-radius allowed the shooter to make more accurate shots. As soon as you put optics on a rifle, the advantage of sight-radius is lost. For shooting out to 300 yards that the OP was talking about, short barrels, moderate BC bullets rule.
 
Originally Posted By: dtechDan, I probably just didn’t use correct punctuation. I wasn’t making a distinction between a 6.8 and a 6.8 “big bore”. Again, the point I was trying to make was: If weight is a concern, the larger bore 6.8 (as compared to a 6mm bore) will allow you a much lighter rifle.

There are several reasons that the larger bore is a better fit for the hunting you described:

1) If you take a line of cartridges, like the ones based off of the .308 Winchester, Or the DTI line, as you go up in bore diameter, the energy goes up as well. Pressure is the limiting factor. The same pressure applied to a larger surface area (larger diameter bullet) the more force you get out of it.

2) As the bore diameter goes up in a cartridge family, the length of barrel necessary to burn the powder goes down.

3) Along with diminishing need for barrel-length comes the ability to shorten the gas-system without compromising performance, or reliability. The big up-side to a shorter gas-system is a lighter barrel.

Keep in mind: All things being equal, barrel rigidity is what gives you accuracy. Barrel rigidity can come two ways: Large diameter, or short. In other words, the longer the barrel, the heavier it has to be to retain accuracy. When you get down to an 18” barrel, it doesn’t have to have a large diameter to be just as rigid and accurate as a MUCH heavier 22” barrel.

I talk to folks all the time that stil have the misconception that longer barrels are more accurate. That notion comes from the days of iron-sights. The longer sight-radius allowed the shooter to make more accurate shots. As soon as you put optics on a rifle, the advantage of sight-radius is lost. For shooting out to 300 yards that the OP was talking about, short barrels, moderate BC bullets rule.

No sorry for that.. That was my bad.. When you said big bore 6.8, It didn't register you was talking about the 6mm bullet family with the 25dti thrown in there.. I apologize for that..

As for the longer barrel, I wanted the most speed with the bullet I was going to use.. What barrel length would be the choice in the 6.8 and 95 to 110 gr bullet? I want to keep the best velocity along with the bullet that is made strictly for hunting..

Also thank you for letting me think outside the box when it comes to heavier bullets and bore along with barrel length.. Dan
 
Originally Posted By: dan158I would like to build a deer and black bear AR 15.. Max be 300 but more realistic max would be 150.. I was thinking about 6.5 or the 6.8..

I seen on bear whisperer he has taken a couple Black bears with the 6.8 is why I was leaning that way..

Or would a 6 or 6.5x 6.8??

What would other suggestions be strictly on the AR15 platform with 22 inch barrel..

Also bullet choice for caliber chosen..


I Don't want to build a 10 because of weight.. Thank you.. Dan

My .02.......

I am no ballistics expert by any stretch of the imagination but I have shot a good many hogs with the AR platform. I have tried the .223, 6.5 Grendel, 6.8 SPC, 300 BLK, and 308.

If I had to choose one it would be the 6.8 SPC running 110 grain Nosler Accubonds or 110 Grain Barnes TSX. The Grendel shoots nice but I was running Hornady 123 grain SST ammo and I was not getting the terminal performance of the 6.8 SPC. You will also get a lot more ammo choices with the 6.8 if you use factory ammo and do not reload.

If you run the 6.8 SPC you will not need the 22 inch barrel. As I understand it most 6.8 ammo is loaded to get a full powder burn in a 16 inch barrel so a 16 or 18 inch should do the job at 300 yards and under. If you go 6.8 I would look for an 11 - 11.25 twist barrel. I use the AR15 Performance Socom profile barrels in all of my builds.

http://ar15performance.com/6_8___cats

You also mentioned weight...... I recently purchased a Savage MSR 10 Hunter in 6.5 Creedmoor. This is a proprietary design by Savage and the Creedmoor version is 8 lbs and the 308 model is 7.8 lbs. This rifle feels more like an AR15 but I have not field tested it yet on the hogs so I cannot give you any comparisons based on actual hunting scenarios. Most of my shooting is at running hogs so for me it is a balance between terminal velocity and recoil recovery for follow up shots.

https://www.savagearms.com/firearms/model/msr10hunter
 
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iffin you're gonna be huntin at 150 yds realistically, and up to 300 max - have you looked at the big bore ars at all?

458 socom, 450 bushmaster, and 50 beowulf

any of the three is capable of launching 250gr an up projo's handily, work on a standard ar lower, and have bullets with big flat meplats available for bone crunching penetration.


just as one example - take a 450 bushmaster, and stuff a lehigh extreme penetrator into it and you've got one mean round on your hands
https://www.lehighdefense.com/collection...iant=1097146160

or a barnes buster 325gr
https://www.midwayusa.com/product/321286...-base-box-of-50


either of the above should be more than capable of helping a bear rapidly achieve room temperature.



and the 450 has proven itself more than capable deer slayer here in the great lakes region where a bunch of states have allowed straight walled carteidges in their caliber restricted hunting areas. its quickly becoming a king of the cornfields type of round - even with just the standard factory 250 ftx. handloaders are having a ball with it and stuff like the 200gr barnes XPB is a nice flat shooting (relatively) bullet more than capable of knocking deer down, among a host of other bullets suitable for the task.
 
Originally Posted By: Gman757Originally Posted By: dan158I would like to build a deer and black bear AR 15.. Max be 300 but more realistic max would be 150.. I was thinking about 6.5 or the 6.8..

I seen on bear whisperer he has taken a couple Black bears with the 6.8 is why I was leaning that way..

Or would a 6 or 6.5x 6.8??

What would other suggestions be strictly on the AR15 platform with 22 inch barrel..

Also bullet choice for caliber chosen..


I Don't want to build a 10 because of weight.. Thank you.. Dan

My .02.......

I am no ballistics expert by any stretch of the imagination but I have shot a good many hogs with the AR platform. I have tried the .223, 6.5 Grendel, 6.8 SPC, 300 BLK, and 308.

If I had to choose one it would be the 6.8 SPC running 110 grain Nosler Accubonds or 110 Grain Barnes TSX. The Grendel shoots nice but I was running Hornady 123 grain SST ammo and I was not getting the terminal performance of the 6.8 SPC.

If you run the 6.8 SPC you will not need the 22 inch barrel. As I understand it most 6.8 ammo is loaded to get a full powder burn in a 16 inch barrel so a 16 or 18 inch should do the job at 300 yards and under. If you go 6.8 I would look for an 11 - 11.25 twist barrel. I run the AR15 Performance Socom profile barrels in all of my builds.

http://ar15performance.com/6_8___cats

You also mentioned weight...... I recently purchased a Savage MSR 10 Hunter in 6.5 Creedmoor. This is a proprietary design by Savage and the Creedmoor version is 8 lbs and the 308 model is 7.8 lbs. This rifle feels more like an AR15 but I have not field tested it yet on the hogs so I cannot give you any comparisons based on actual hunting scenarios.

https://www.savagearms.com/firearms/model/msr10hunter


Thank you for the info..
Right now we are not allowed to hunt with semi autos for big game.. But I expect that to change within couple years if not next..

I do have couple browning A bolts 7mm wsm and a 30-06.. Both are factory weight 7.3lbs I believe..I am just enjoying hunting with my ARs for predators that I would like to use for big game also..
And I can use for predators also and have it when and if they become legal to use in my state..

Dan
 
Originally Posted By: Plant.Oneiffin you're gonna be huntin at 150 yds realistically, and up to 300 max - have you looked at the big bore ars at all?

458 socom, 450 bushmaster, and 50 beowulf

any of the three is capable of launching 250gr an up projo's handily, work on a standard ar lower, and have bullets with big flat meplats available for bone crunching penetration.


just as one example - take a 450 bushmaster, and stuff a lehigh extreme penetrator into it and you've got one mean round on your hands
https://www.lehighdefense.com/collection...iant=1097146160

or a barnes buster 325gr
https://www.midwayusa.com/product/321286...-base-box-of-50


either of the above should be more than capable of helping a bear rapidly achieve room temperature.



and the 450 has proven itself more than capable deer slayer here in the great lakes region where a bunch of states have allowed straight walled carteidges in their caliber restricted hunting areas. its quickly becoming a king of the cornfields type of round - even with just the standard factory 250 ftx. handloaders are having a ball with it and stuff like the 200gr barnes XPB is a nice flat shooting (relatively) bullet more than capable of knocking deer down, among a host of other bullets suitable for the task.

Can those be necked down to seat a 30 caliber bullet in it?? I seen youtube video on the 458soc.. Had a little recoil to it.. Dan
 
Originally Posted By: dan158Thank you for the info..
Right now we are not allowed to hunt with semi autos for big game.. But I expect that to change within couple years if not next..

I do have couple browning A bolts 7mm wsm and a 30-06.. Both are factory weight 7.3lbs I believe..I am just enjoying hunting with my ARs for predators that I would like to use for big game also..
And I can use for predators also and have it when and if they become legal to use in my state..

Dan

Am I the only one confused here ?
w00t.gif


 
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Didn't they chamber the 25 WSSM in the AR-15 Platform at one time. I know brass can be problematic but shooting 25-06 ballistics out of an AR-15 would do the job. 100gr Partition or one of the under 100gr Barnes copper bullets would work well.
 
Originally Posted By: dan158

Can those be necked down to seat a 30 caliber bullet in it?? I seen youtube video on the 458soc.. Had a little recoil to it.. Dan


the 450 bushmsater reocoil isnt awful. if you can handle a 30-06 bolt gun, a 450 bushmaster is no problem.


the 30 remington AR cartridge is actually just what you asked about - a 450 bushmaster necked down to 30 cal. however they're currently out of production.

a member here actually has one for sale right now

http://www.predatormastersforums.com/for...291#Post3110291


its a neat caliber, and if wasnt in the process of building a 6x45, i'd be seriously interested. 125 sst's at 2800 fps would be one mean freaking deer load!
 

Bear?

These things are a PITA. They tear up my feeders and when they show up the hog hunting is over because they won't leave until I run them off to get to my truck.

Time stamp incorrect.... 12/14/2017 5:30am.

qliMl1F.jpg
 
OK, so I have a 458 SOCOM, a couple of 6.8 SPCs, and one 6mm WOA(6mm wildcat, with the 6.8 SPC as the parent case). Any of these make great deer rifles, but if you add bears, then IMHO that takes the 6mm out of the discussion. If we are talking black bears, the 6.8 SPC is plenty of gun. I took a mature northern whitetail doe this year, and 6.8mm 95 gr. Barnes Triple Shock, I loaded, made for an impressive autopsy. Plenty of damage, penetration, and tissue pudding to consider this a very viable round for black bear. But if you are into big hammers, then one of the big bore AR-15 cartridges(450 Bush, 458 SOCOM, 50 Beowulf) will leave no doubt they will take down bears. For the 458 SOCOM, I added a LimbSaver recoil pad to my Magpul ACS stock, and that smoothed out the recoil. Think of something like the recoil of a 20 ga. shotgun, with a magnum load. Add the Limbsaver to that, and it gets pretty mild. Just make sure you have enough length of pull on the adjustable stock, to keep the scope from biting. I bounced a scope off my shooting glasses, last time on the bench, when I wasn't paying attention to how far I extended the Magpul...Now I pay more attention to that.
grin.gif


Squeeze
 


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