280ai or 6.5 creedmoor

robtattoo

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Please explain how a "regular hunting bullet" will beat a "long slippery" bullet terminally based on that fact?







Its always a constant that those who kill the least are the most adamant that "bigger is better".

Well, if you have 2 projectiles of identical weight, one short & fat, one long & thin, traveling at identical velocity, the fatter will impart slightly-significantly more impact force, depending on frontal difference. In this case we're only talking about 0.2mm.........




No offence taken ;)
 

Stid2677

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Not to derail the thread, but is that an adirondak dipped in Vias?

Yes Sir,, Dipped in Vias, with a dura grip clear and all the steel cerakoted in flat black. Topped with Talleys and a Swaro Z5 Sheep hunter.
 
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I have a .280 AI and I love that rifle. Shot my first animal with it last fall, a large cow elk one shot at 450 yards. She went about 30 feet and tipped over.
 

GKPrice

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Customs not included there only a few factory guns that fall into a true ultra-light to lightweight rifles that one can depend on to be a shooter out of the box "MOST" of the time - Kimber sort of owns the ultra-light title, and for a very reasonable price I might add - I realize that I'm beginning to sound like a broken record but for a very nominal step up in weight that is still "lightweight" (and to many who've picked up one of mine, amazingly lightweight) you can have a pretty darn light, well balanced affordable rifle that looks great and has become almost legendary for out of the box accuracy for $749 at any Sportsmans Warehouse in a Tikka T3x superlight - change out ONE thing, the recoil pad to a Limbsaver Gen 2, and unless a small youth, small woman or unusually sensitive to recoil, in 30.06 makes one of if not the best darn all around HUNTING rifle available today - And since the Kimber Hunter was also mentioned, griping about the magazine is a non-issue because I have a Hunter and the magazines are not nearly as easy to deal with as the Tikka clip and now cheaper than the Kimber too - I realize that Alaska can throw a "kink" into that but, there would be nothing illegal for a Rokslide member who lives near a SW to purchase a superlight, decide that particular rifle is not for them and post it for sale, to be transferred through an FFL in Alaska (the 2 local shops I deal with in Oregon seem happy enough to make an easy $25 for the transfer) - just a "thought" and given the tight knit and honest nature of Rokslide, not a stupid suggestion IMO
 

GKPrice

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Start with the bullet and work your way back to the headstamp. 6.5's are the hot ticket now, but your 7-08 with 162's is about all the 30-06 you need. Maybe forgo the 280AI and punch your 7-08 AI of its already the weight your looking for. Seems you have the middle pretty much covered and plenty of overlap as it is.

Id be more tempted to throw a 243 in the mix if it were me.

16Bore just jogged my memory, I used to have a 7mm-08AI the I let a rancher friend talk me out of for his wife - she still uses it and has 1 or 2 punched tags per year using it since that infamous trade occurred many years ago - 7mm-08 AI is a damn fine round
 

GKPrice

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16Bore just jogged my memory, I used to have a 7mm-08AI the I let a rancher friend talk me out of for his wife - she still uses it and has 1 or 2 punched tags per year using it since that infamous trade occurred many years ago - 7mm-08 AI is a damn fine round

in that particular instance it would have been MORE than a fair trade .....
 

Tag_Soup

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Well, if you have 2 projectiles of identical weight, one short & fat, one long & thin, traveling at identical velocity, the fatter will impart slightly-significantly more impact force, depending on frontal difference. In this case we're only talking about 0.2mm.........




No offence taken ;)

Sorry, but this is where I would have to disagree. It would seem that your statement is correct, but let's look at the physics.

If I take the afore mentioned 160gr nosler partition out of a 280 AI using nosler custom shop ammo, I get a muzzle velocity of 2950 fps. I push a 130 gr VLD at 2950 fps with my little 6.5 cm, so let's use that for argument sake. We will also make the assumption that the animal is fairly close as the partition will lose more velocity at distance due to a lower BC.

Now let's assume the "wider and flatter" bullet goes completely through the animal, retaining the majority of its weight, as it is designed. Let's call its exit velocity 500 fps.

We will also assume the VLD fragments and the majority of the bullet does not exit the animal (I.e. Exit velocity = 0).

We have to convert to correct units and since metric is easier, I will use that.

Our governing equation for Kinetic energy is:
Ke = 1/2*mass*velocity^2

So, for the Nosler partition, our equation with converted mass and velocity is:

Ke_total = Ke_impact - Ke_exit
Ke_impact = 1/2*0.0103678(kg)*899.16(m/s)^2
Ke_exit = 1/2*0.0103678(kg)*152.4(m/s)

=> Ke_160Nosler = 4070.73 N

For the VLD, our equation is:

Ke_total = 1/2*0.00907185(kg)*899.16(m/s)^2

=> Ke_130VLD = 3667.25 N

In this case I have given every assumed advantage to the Nosler partition that I could. Even in the perfect scenario, the little 6.5 cm holds its own. As ranges extend, the higher BC bullet will continue to gain advantage. This is all moot once you load a 180gr VLD into the 280 AI though...then it will walk on the 6.5.

Yes, there is slightly more Kenetic energy dispersed on target in our example above, but for what cost? I would greatly prefer a small handy rifle that shoots very high BC projectiles with low recoil than just go with the larger caliber. This just goes to show that it isn't all about wider flatter bullets.

This is all just my $0.02 and shows my personal preference. I have friends that kill more animals than I do with Walmart special 30-06 Remington's and the cheapest ammo they can get their hands on. I would say look at your realistic maximum shooting distance, preferred game species, and reloading skills. Once you have honestly assessed these, a caliber choice should be easier.


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robtattoo

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Ain't no arguing with physics!

Well, other than your parameters are incorrect. Your calculations only take mass & velocity into consideration, not sectional density, pressure dispersion (N cm^2) etc....
I'm no physicist or mathematician & I've never stayed in a Holiday inn, but I would assume that these factors play heavily into the impact force directly applied. I wouldn't even begin to know how that's even calculated! All I know is that things I've shot with my .308 & 150gn bullet have reacted more violently & dropped quicker than things I've shot with a 140vld from my 6.5.
I have no way to actually prove any of this & it's kinda inconsequential as they're all equally dead.

To be fair & apologetic to the OP, this is all pretty academic, either choice will be great for your needs! :D Sorry for the meander!
 

TwoTikkas

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I have both,, you get a a couple hundred FPS faster and more down range energy with the 280AI over the CM. Within 300 yards both do about the same, with the 280ai having greater muzzle flip and recoil. The 280ai has a sharp shoulder, so the CM feeds much better IMHO. Much greater selection of factory ammo for the CM over the 280ai. Comes down to what you want to brag about around the fire, a plain old 270 or 30-06 will do the same and maybe even better. But, hey I like sexy too and enjoy working up reloads during the winter. The 6.5mm Creedmore is a soft shooter for sure and will be my wife's new rifle.

Kimbers_zpslrxjogxq.jpg

If that pic doesn't give a fella Kimber fever,nuttin will!
 

luke moffat

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Sorry, but this is where I would have to disagree. It would seem that your statement is correct, but let's look at the physics.

If I take the afore mentioned 160gr nosler partition out of a 280 AI using nosler custom shop ammo, I get a muzzle velocity of 2950 fps. I push a 130 gr VLD at 2950 fps with my little 6.5 cm, so let's use that for argument sake. We will also make the assumption that the animal is fairly close as the partition will lose more velocity at distance due to a lower BC.

Now let's assume the "wider and flatter" bullet goes completely through the animal, retaining the majority of its weight, as it is designed. Let's call its exit velocity 500 fps.

We will also assume the VLD fragments and the majority of the bullet does not exit the animal (I.e. Exit velocity = 0).

We have to convert to correct units and since metric is easier, I will use that.

Our governing equation for Kinetic energy is:
Ke = 1/2*mass*velocity^2

So, for the Nosler partition, our equation with converted mass and velocity is:

Ke_total = Ke_impact - Ke_exit
Ke_impact = 1/2*0.0103678(kg)*899.16(m/s)^2
Ke_exit = 1/2*0.0103678(kg)*152.4(m/s)

=> Ke_160Nosler = 4070.73 N

For the VLD, our equation is:

Ke_total = 1/2*0.00907185(kg)*899.16(m/s)^2

=> Ke_130VLD = 3667.25 N

In this case I have given every assumed advantage to the Nosler partition that I could. Even in the perfect scenario, the little 6.5 cm holds its own. As ranges extend, the higher BC bullet will continue to gain advantage. This is all moot once you load a 180gr VLD into the 280 AI though...then it will walk on the 6.5.

Yes, there is slightly more Kenetic energy dispersed on target in our example above, but for what cost? I would greatly prefer a small handy rifle that shoots very high BC projectiles with low recoil than just go with the larger caliber. This just goes to show that it isn't all about wider flatter bullets.

This is all just my $0.02 and shows my personal preference. I have friends that kill more animals than I do with Walmart special 30-06 Remington's and the cheapest ammo they can get their hands on. I would say look at your realistic maximum shooting distance, preferred game species, and reloading skills. Once you have honestly assessed these, a caliber choice should be easier.


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So a VLD would be a better choice than a partition? Just curious cause the dozen or so animals I have seen shot with VLDs are not that impressive. Yes still dead, but if shooting less than 400 yards I don't see an advantage of the VLDs.

Even if the math above is 100% unbiased I'd still be hard pressed to pick a VLD over a partition or bonded bullet on brown bear and mountain goats. Anything other than deer and goats in Alaska dies pretty easy and thus it really doesn't matter too much what bullet you choose.
 

GKPrice

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Sorry, but this is where I would have to disagree. It would seem that your statement is correct, but let's look at the physics.

If I take the afore mentioned 160gr nosler partition out of a 280 AI using nosler custom shop ammo, I get a muzzle velocity of 2950 fps. I push a 130 gr VLD at 2950 fps with my little 6.5 cm, so let's use that for argument sake. We will also make the assumption that the animal is fairly close as the partition will lose more velocity at distance due to a lower BC.

Now let's assume the "wider and flatter" bullet goes completely through the animal, retaining the majority of its weight, as it is designed. Let's call its exit velocity 500 fps.

We will also assume the VLD fragments and the majority of the bullet does not exit the animal (I.e. Exit velocity = 0).

We have to convert to correct units and since metric is easier, I will use that.

Our governing equation for Kinetic energy is:
Ke = 1/2*mass*velocity^2

So, for the Nosler partition, our equation with converted mass and velocity is:

Ke_total = Ke_impact - Ke_exit
Ke_impact = 1/2*0.0103678(kg)*899.16(m/s)^2
Ke_exit = 1/2*0.0103678(kg)*152.4(m/s)

=> Ke_160Nosler = 4070.73 N

For the VLD, our equation is:

Ke_total = 1/2*0.00907185(kg)*899.16(m/s)^2

=> Ke_130VLD = 3667.25 N

In this case I have given every assumed advantage to the Nosler partition that I could. Even in the perfect scenario, the little 6.5 cm holds its own. As ranges extend, the higher BC bullet will continue to gain advantage. This is all moot once you load a 180gr VLD into the 280 AI though...then it will walk on the 6.5.

Yes, there is slightly more Kenetic energy dispersed on target in our example above, but for what cost? I would greatly prefer a small handy rifle that shoots very high BC projectiles with low recoil than just go with the larger caliber. This just goes to show that it isn't all about wider flatter bullets.

This is all just my $0.02 and shows my personal preference. I have friends that kill more animals than I do with Walmart special 30-06 Remington's and the cheapest ammo they can get their hands on. I would say look at your realistic maximum shooting distance, preferred game species, and reloading skills. Once you have honestly assessed these, a caliber choice should be easier.


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GEEEZ ! Let's just go huntin' will ya ?
 

Tag_Soup

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So a VLD would be a better choice than a partition? Just curious cause the dozen or so animals I have seen shot with VLDs are not that impressive. Yes still dead, but if shooting less than 400 yards I don't see an advantage of the VLDs.

Even if the math above is 100% unbiased I'd still be hard pressed to pick a VLD over a partition or bonded bullet on brown bear and mountain goats. Anything other than deer and goats in Alaska dies pretty easy and thus it really doesn't matter too much what bullet you choose.

I'm not necessarily saying either is better or worse, just giving some justification as to why the 6.5 creedmore can have some advantages depending on choice of components. My purpose was mostly to illustrate that when using high BC bullets, a small 6.5 or 260 can hold its own in the KE department for the reloader.

I have personally had great performance with both "traditional" bullets and secant ogive hollow points, the Berger hunting VLD's in particular. I have had only good experiences with the bergers, while having one very bad experience with some 30 cal ballistic tip bullets from a major manufacturer. This is just my experience and that of some friends, but I have found every animal shot with VLD's in the lungs to have a near instant mortality and jellied lungs/circulatory organs.

Cheers




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luke moffat

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I'm not necessarily saying either is better or worse, just giving some justification as to why the 6.5 creedmore can have some advantages depending on choice of components. My purpose was mostly to illustrate that when using high BC bullets, a small 6.5 or 260 can hold its own in the KE department for the reloader.

I have personally had great performance with both "traditional" bullets and secant ogive hollow points, the Berger hunting VLD's in particular. I have had only good experiences with the bergers, while having one very bad experience with some 30 cal ballistic tip bullets from a major manufacturer. This is just my experience and that of some friends, but I have found every animal shot with VLD's in the lungs to have a near instant mortality and jellied lungs/circulatory organs.

Cheers




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Gotcha....still think the 280AI is more versatile than the little 6.5, but to each their own.
 

Tag_Soup

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Gotcha....still think the 280AI is more versatile than the little 6.5, but to each their own.

I completely agree, just may not be able to get higher BC bullets to fit the factory mag box on the 280 AI kimber, whereas probably would be able to in the 6.5. That was the point I was trying to bring up for the OP to weigh as pros/cons. The rest was off topic for the most part.


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luke moffat

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I completely agree, just may not be able to get higher BC bullets to fit the factory mag box on the 280 AI kimber, whereas probably would be able to in the 6.5. That was the point I was trying to bring up for the OP to weigh as pros/cons. The rest was off topic for the most part.


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Which really only matters that much when shooting beyond 500 or so yards.....and after that the 6.5 is getting a bit light for anything but deer here in Alaska.

Both rounds shooting 140 accubonds the "stubby" 280 AI 140 accubond is .485 going 3200 fps and the "sleek" 140 accubond from the creed with a .509 going 2700 fps.

At 500 yards the 140 creedmor has 1100 fpe whilst the 280 AI 140 accubond is going nearly 400 fps faster and carrying over 40% more energy.

The creedmor as a long range hunting cartridge doesn't appeal to me that much. High BC bullets really don't mean much like I said when you can't carry the energy out there anyways. Even .6 BC out of a Creedmor is still only got just over 1200 fpe at 500 yards.

Maybe I am looking at it all wrong I guess.
 
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