280ai or 308win for both 600 yard deer and bear?

[hodgeman]

Congratulations- the Montana in .308 is an excellent rifle.

I gotta agree with Luke...keep it simple- a 165 or 180r Accubond or Scirocco (whatever the rifle likes) and use it for everything. There is so little difference in ballistics and on game performance that it's not worth the hassle of fooling with a bunch of different stuff. Especially if you get something like a CDS dial- just range it and dial it...keep it simple!


Just find one the gun likes that does what you want on critters- then get it in volume.

 

[huntin'monkey]

Thanks for all the info, I've got a Montana Kimber .308 ordered. I'm super excited. My plan is to find a couple different loads, one with a 180 grain for Bear protection and the something with either 150 or 165 grain for deer and elk.

Any specific factory loads that you guys would suggest? Any tips on zeroing in a scope for two different loads? Is it possible to zero for one load and still use the other load or would I have to zero for each load?

I used to go this route with my .308 but don't anymore. Here's why. I've killed several deer with the 165 grain accubond, but all of them stayed on their feet for at least a little bit and a few moved off and required some level of effort to find. I shot a doe in the bottom of the heart and the bullet tore a fist sized chunk out of her chest, yet she made it into some really thick cover before piling up. It was pretty surprising how hard it was to find her, considering the size of the wound.

I decided to try 180 grain accubonds for both deer and elk because of the last ammo shortage. I've since killed two blacktail bucks with the heavier bullet, and both were knocked over by the shot and didn't get back on their feet. I shot the buck in my avatar at 90 plus yards on flat ground and he just flipped onto his back and started kicking the air. He would have run off to die somewhere else if it had been a 165 grain bullet. I also shot an elk at over 100 yards and the 180 grainer knocked him off his feet. I don't feel that the 165 grain bullets did less damage to the meat and the difference in trajectory isn't a huge difference at the distances I hunt. But having a bullet that carries more energy downrange and literally knocks animals down is a huge difference.

 

[Eagle]

I used to go this route with my .308 but don't anymore. Here's why. I've killed several deer with the 165 grain accubond, but all of them stayed on their feet for at least a little bit and a few moved off and required some level of effort to find. I shot a doe in the bottom of the heart and the bullet tore a fist sized chunk out of her chest, yet she made it into some really thick cover before piling up. It was pretty surprising how hard it was to find her, considering the size of the wound.

I decided to try 180 grain accubonds for both deer and elk because of the last ammo shortage. I've since killed two blacktail bucks with the heavier bullet, and both were knocked over by the shot and didn't get back on their feet. I shot the buck in my avatar at 90 plus yards on flat ground and he just flipped onto his back and started kicking the air. He would have run off to die somewhere else if it had been a 165 grain bullet. I also shot an elk at over 100 yards and the 180 grainer knocked him off his feet. I don't feel that the 165 grain bullets did less damage to the meat and the difference in trajectory isn't a huge difference at the distances I hunt. But having a bullet that carries more energy downrange and literally knocks animals down is a huge difference.

Where were the impacts on the two animals that dropped at the shot? I'm guessing high shoulder? Generally, any animal will drop on the spot if the shot hits in that high shoulder/spine location and it's a quick death, I doubt 15 grains in weight made much of a difference compared to shot placement. Most animals hit low in the heart will be able to cover some ground, but a high shoulder shot will cause instant paralysis due to the shock of the bullet strike near the spine.

 

[greyghostnw]

I have to disagree here,

After seeing over 20 grizzlies and 20 mountain goats killed apiece I will say I strongly feel mountain goats are heartier critters and very few people would say a .308 or a 270 isn't enough gun. Seen everything used to kill both from 308, 270s up to 338WMs and 375s.

I have personally taken grizzlies with a 308 and witnessed more killed with a 308 win as well. No doubt a 280 AI will as well. But bear hunting for me is always a sub 200 yards affair. If you are wanting to shoot grizz long range then get a mag for sure.

But my 21" 338-06 with 210 sciroccos like Axel mentioned is what I will likely take on dedicated bear hunts. But for the summer rambles where grizz season is open my wife and I will our sub 5 pound .308 loaded with some 200 grainers at 2550 and take one if we can get in position.

That said if you already have a 7-08 a .308 isn't a big enough of a jump to warrant getting that. I would jump up to a 30-06 Montana if you like. Be aware that shooting 180 grainers at 2900 fps in a 6-6.5 all up rifle will recoil for certain unless you brake it. Can't have superlight and more power without getting more recoil as both reducing weight and burning more power and heavier bullets all equal more recoil.

That said the 250 Aframes are certainly managable at 2500+ fps, but make no mistake, its bringing the heat for sure on both ends


Here is my Kimber Montana 338-06 after some mods as a bare rifle:


Put a 17 oz scope on it and you end up here:


Here is that 6 pound scoped 338-06 next to the 5 pound 308 with peep on it.


Both are packing more then enough heat to take grizz in my experience.

curious......... my bolt action 308's have 1/12 barrels, as i assume your kimbers do as well. 150's stabilize best, 165's are acceptable but not as accurate as 150's. barnes ttsx is my choice, have tried anything possible to buy. how does yours stabilize 200's seems like a 1/10 is a must for 165's and up. at least with my experience.

 

[AXEL]

Agreed, I can recall a Blacktail buck, shot with my old P-64 Fwt.-.270 Win. loaded with the 150 NP at 2900 fps-mv which I hit in the heart and which ran almost 100 yds. into deep Vancouver Is. bush and then died before I could get to it.

I have shot several others, same age class, etc. in this immediate area, using my old Husqvarna 4100-7x57, loaded with 140 NPs at about 2700, making high lung shots and every one of these dropped "bang-flop" and never moved.

So, IME/IMO, shot placement and bullet performance IS the determining factor when relatively "equal" cartridges are used.

 

[luke moffat]

I have primarily shot 165s and 180s in my 308s. I don't notice much of a difference in preformance between 165s and 180s when shooting at caribou or lesser sized animals with a 308. As caribou and smaller rarely "catch" the bullets and most are complete pass throughs so getting more then enough penetration and neither is expending all its energy in the animal. Granted this is based on roughly 60-70 animals I have seen shot with a 308 so YMMV. That said I like 180 grainers better as well for extra penetration on stouter animals like bears, mountain goats, or moose.

 

[robby denning]

I didn't read the whole thread but hopefully someone mentioned the 270 Win Short Mag. pretty impressive ballistics and matches well with a lightweight platform.

 

[luke moffat]

curious......... my bolt action 308's have 1/12 barrels, as i assume your kimbers do as well. 150's stabilize best, 165's are acceptable but not as accurate as 150's. barnes ttsx is my choice, have tried anything possible to buy. how does yours stabilize 200's seems like a 1/10 is a must for 165's and up. at least with my experience.

Yes my wife and I both have Kimbers in 308 and they are 1:12 twist.

Did you shoot 180 grainers and find them to keyhole (hit the paper sideways). My buddy and I loaded up some 200 accubonds and his Savage 99 with a 1:12 twist keyholed them while my Kimber and Remington Model 7 both shot fine.

That for 200 grainers I will be loading partition, woodleighs, or a frames (all of which are shorter bullets than a 165 accubond or 168 bergers) with no ill effects so maybe the short stubbier bullets help with that?

A gentleman I have corresponded from Montana with shoots 208 A maxes out of his 20" that has a 1:12 twist with great success out to 1000 yards or more. Given that coupled with my experience with 200 grainers of multiple bullet types I find that 1:10 isn't a must at all for some 200 grainers and certainly not for 180s. But some rifles may be less tolerant.

Curious as to what you say as far as indicators of the bullets not stabilizing

 

[jwatts]

Yes my wife and I both have Kimbers in 308 and they are 1:12 twist.

Did you shoot 180 grainers and find them to keyhole (hit the paper sideways). My buddy and I loaded up some 200 accubonds and his Savage 99 with a 1:12 twist keyholed them while my Kimber and Remington Model 7 both shot fine.

That for 200 grainers I will be loading partition, woodleighs, or a frames (all of which are shorter bullets than a 165 accubond or 168 bergers) with no ill effects so maybe the short stubbier bullets help with that?

A gentleman I have corresponded from Montana with shoots 208 A maxes out of his 20" that has a 1:12 twist with great success out to 1000 yards or more. Given that coupled with my experience with 200 grainers of multiple bullet types I find that 1:10 isn't a must at all for some 200 grainers and certainly not for 180s. But some rifles may be less tolerant.

Curious as to what you say as far as indicators of the bullets not stabilizing

The length of the bullet has a lot to do with the ability of a given twist rate to stabilize it. It just typically works out that the heavier bullets are longer. I don't shoot much long range, but I do load heavy subsonics for my 300 blackout and 308. The longer 220s and 208s will not stabilize in my 1/10 twist at subsonic speeds, but will stabilize in my 1/8. These are very long bullets. There is a calculator that I found handy when figuring out if a load would be stable or not. My main concern was stability at the muzzle since I didn't want to strike a baffle in my suppressor. Here is the calculator:

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

 

[greyghostnw]

Yes my wife and I both have Kimbers in 308 and they are 1:12 twist.

Did you shoot 180 grainers and find them to keyhole (hit the paper sideways). My buddy and I loaded up some 200 accubonds and his Savage 99 with a 1:12 twist keyholed them while my Kimber and Remington Model 7 both shot fine.

That for 200 grainers I will be loading partition, woodleighs, or a frames (all of which are shorter bullets than a 165 accubond or 168 bergers) with no ill effects so maybe the short stubbier bullets help with that?

A gentleman I have corresponded from Montana with shoots 208 A maxes out of his 20" that has a 1:12 twist with great success out to 1000 yards or more. Given that coupled with my experience with 200 grainers of multiple bullet types I find that 1:10 isn't a must at all for some 200 grainers and certainly not for 180s. But some rifles may be less tolerant.

Curious as to what you say as far as indicators of the bullets not stabilizing

my groups get larger with heavier bullets, shrink back up with the 150's....

 

[luke moffat]

The length of the bullet has a lot to do with the ability of a given twist rate to stabilize it. It just typically works out that the heavier bullets are longer. I don't shoot much long range, but I do load heavy subsonics for my 300 blackout and 308. The longer 220s and 208s will not stabilize in my 1/10 twist at subsonic speeds, but will stabilize in my 1/8. These are very long bullets. There is a calculator that I found handy when figuring out if a load would be stable or not. My main concern was stability at the muzzle since I didn't want to strike a baffle in my suppressor. Here is the calculator:

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

I hear ya….which is why I mentioned I use short stubby bullets that seem to work well. That said that 200 accubond is pretty long and it still seemed to be stabile when driven to only 2500 fps out of a 308 win 20" barrel.

 

[luke moffat]

my groups get larger with heavier bullets, shrink back up with the 150's....

That certainly is interesting, for sure go with whatever your rifle likes, but I wonder if playing with another bullet, powder or seating depth could change that, maybe it was just a load your rifle liked?

Either way sounds like the 150 TTSXs work for you so if you are happy with them, rock on!!

 

[Clarktar]

Probably a lousy question, but can a standard 280 remington be changed to a 280 AI? Does the bolt need work? Do you just have to ream the chamber?

 

[GKPrice]

Clarktar - just make sure the gunsmith you choose is well experienced with "improved" chambers and how to do it properly - there is a fine line when reaming the throat so you are able to fireform rounds by shooting them rather than by just pointing the barrel in the air and pulling the trigger - I had a guy do a Ruger rechamber for me years ago and that's what I ended up with as opposed to someone like Darrell Holland (Powers OR) who knows precisely how to set the depth - I can shoot .223 fireform loads by the 100's at prairie dogs and have a ball, ending up with fireformed .223 AI brass and piles of PD bodies in the towns - Varmint Hunter magazine archives has dozens of reference info - look up Steve Timm articles

 

[AXEL]

Yup, doing this is NOT simply a "ream job" and it requires skill in setting headspace AND, what seems to be ignored here, the issue of FEEDING from the mag. into your new, improved chamber.

I very strongly prefer CRF hunting rifles and all of my currently operational 29 bolt action rifles are CRF models, except one, full custom, sts Rem. Mod. 7, ultralight 7/08.

IF, you choose a genuine Mauser 98 type action, ie, P-64 Mod. 70, Brnos/almost all CZs, HVAs, FNs-MKXs, reworked military Mausers, such as the highly desirable G-33/40 aka VZ-33, small ring, you will probably encounter some feeding issues concerning the "rails" as the round moves from the mag. into the chamber.

Correctly adjusting this is one of the skills that differentiates between even a highly skilled machinist and a real gunsmith....this is long, sometimes bitter experience talking........

I have avoided "AI" rounds for this reason, but, a good smith can make it all happen the way one wants it and the extra velocity of the "AI" cannot hurt.

 

[huntin'monkey]

Where were the impacts on the two animals that dropped at the shot? I'm guessing high shoulder? Generally, any animal will drop on the spot if the shot hits in that high shoulder/spine location and it's a quick death, I doubt 15 grains in weight made much of a difference compared to shot placement. Most animals hit low in the heart will be able to cover some ground, but a high shoulder shot will cause instant paralysis due to the shock of the bullet strike near the spine.

Nope, no high shoulder/spine shots. All of them were heart shots. With both of the blacktail bucks, I only recovered one or two bites worth of the bottom triangle of the heart, which is a bummer because I really like fried heart. On the elk, the impact took off the top of the heart, in about the same location that I hit the doe I heart shot and had run on me.