The 6UM

[atmat]

Problem is I elk hunt in places where 243 is minimum. I'm thinking I'm going to do a 6 cm shooting 115 dtacs out of a 24 inch tube. It will be suppressed, so too long, but really want to be starting at 3000 or more. Would be awesome if I could get to 800 effectively.

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I will be living in CO by Spring for work, so I get it. Hunt with whichever one you want.

But to get practice at the non-magnum local range, buy a 223 to train with. It’ll pay for itself in terms of ammo and barrel life by your first 1,000 rounds of practice.

Compare price of 6creed ammo with 223 ammo. Then factor in a rebarrel by 1500 rounds. It’s cheaper to just buy a second rifle to train with.

 

[Ryan Avery]

The 6CM with good bullets is a 600 yard elk rifle.

 

[Hunter609]

Problem is I elk hunt in places where 243 is minimum. I'm thinking I'm going to do a 6 cm shooting 115 dtacs out of a 24 inch tube. It will be suppressed, so too long, but really want to be starting at 3000 or more. Would be awesome if I could get to 800 effectively.

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My 24” 6cm is 3090 with 115dtacs

 

[longrange13]

Whats the consensus on the tbn coated 115 dtacs? Are they worth the velocity loss?

 

[khuber84]

Whats the consensus on the tbn coated 115 dtacs? Are they worth the velocity loss?

The hbn coated drop pressure, giving you more potential top side velocity before psi, but do require more powder.

 

[wasskeet]

As interesting as this cartridge sounds, I better stay away from this thread !

 

[Archer86]

To keep this 6UM shooting related, here’s two drop charts at our range at 1000’. One for a 16” 6UM shooting 115 NR DTACs at 3140fps and the other is one of our most common builds, a 24” 300 win mag, shooting 212 ELDXs at 2940fps.

View attachment 644933View attachment 644934



The appeal of a shorter, lighter rifle with a fraction of the recoil and same lethality on big game at extended range, is a real thing.

Just out of curiosity is energy not a consideration of lethality on big game at extended range anymore. Seams to be a big difference in that column

 

[Wyo_hntr]

No

 

[gabenzeke]

Just out of curiosity is energy not a consideration of lethality on big game at extended range anymore. Seams to be a big difference in that column

No. Just need the necessary velocity to upset the bullet.

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[GoatPackr]

Speed kills.
Rapid displacement of tissue and fluid. The faster you push a bullet through an animals vitals the larger the crushing wave and larger the wound channel. It's all about speed. More the better

Kris

 

[Archer86]

Speed kills.
Rapid displacement of tissue and fluid. The faster you push a bullet through an animals vitals the larger the crushing wave and larger the wound channel. It's all about speed. More the better

Kris

So those 2 charts everything is virtually identical at extended range except energy which is almost double no consideration is given to that at all? Maybe a 6 ultra manbun is in my future

 

[BjornF16]

So those 2 charts everything is virtually identical at extended range except energy which is almost double no consideration is given to that at all? Maybe a 6 ultra manbun is in my future

Energy is meaningless. Bullet construction and impact velocity is all that really matters. More energy just translates to more recoil and decreased hit rate.

A good primer would be to read the .223 on big game thread

 

[GoatPackr]

So those 2 charts everything is virtually identical at extended range except energy which is almost double no consideration is given to that at all? Maybe a 6 ultra manbun is in my future

Try it. A 100 grain bullet impacting at 3500 fps will cause way more terminal damage than the same diameter 150 grn bullet at 2000 fps. Probably more than a large
Caliber heavy bullet at a slow fps. IE a 300 grn muzzle loader bullet.
Energy is a very small piece of the equation that people who sell rifles and bullets like to brag up to make a sell.

 

[Mountainrancher]

So those 2 charts everything is virtually identical at extended range except energy which is almost double no consideration is given to that at all? Maybe a 6 ultra manbun is in my future

No. “Energy” when expressed as energy ft lbs like on the back of an ammo box or in a ballistic chart is meaningless in terminal effectiveness. The only numbers that matter are impact velocity and the minimum velocity for a bullet to upset.

 

[longrange13]

So those 2 charts everything is virtually identical at extended range except energy which is almost double no consideration is given to that at all? Maybe a 6 ultra manbun is in my future

Nope, if you read into a lot of the research @Formidilosus has done looking at wounds on animals; with heavy for caliber match bullets across many calibers, you almost can’t tell the difference between the wounds. That’s 77tmk in the 223, 108 eldm in the 6mm, 147 eldm in the 6.5, etc up Into the 30 cals. The wounds are all very similar and devastating. As long as the bullet upsets when it impacts, energy doesnt contribute to the kill.

 

[Archer86]

Try it. A 100 grain bullet impacting at 3500 fps will cause way more terminal damage than the same diameter 150 grn bullet at 2000 fps. Probably more than a large
Caliber heavy bullet at a slow fps. IE a 300 grn muzzle loader bullet.
Energy is a very small piece of the equation that people who sell rifles and bullets like to brag up to make a sell.

That's not representing the charts above. A 115 grainn bullet going just over 1900fps and a 212 grain bullet going just over 1900fps at both at 800 yards which one causes more damage and why?

 

[longrange13]

That's not representing the charts above. A 115 grainn bullet going just over 1900fps and a 212 grain bullet going just over 1900fps at both at 800 yards which one causes more damage and why?

@Formidilosus would know better but more than likely both wounds will be devastating and you wouldn’t be able to tell much of a difference between the two. The only way the 212 would do substantially more damage is if you were able to hit the animal a couple hundred fps faster than the other bullet, causing more upset.

Listen to the shoot2hunt podcast episode 35. It explains all this stuff pretty good.

 

[GoatPackr]

That's not representing the charts above. A 115 grainn bullet going just over 1900fps and a 212 grain bullet going just over 1900fps at both at 800 yards which one causes more damage and why?

At the same speed it's going to be the larger caliber. It's displacing more tissue and fluid at a faster rate because it's wider. Assuming same type of bullet performance and impact location being equal.

Nothing to do with energy.

Energy by definition is the ability of an object in motion to stay in motion.
It takes more the larger the frontal area of a bullet. So the larger that area the more weight the bullet needs to be to keep it driving forward.
Another interesting thing. The wide front on a bullet wants to stop it and the heavy shank behind it wants to pass it up. Much like a motor cycle hitting a stump. A faster twist will help the bullet not want to swap ends and continue a straighter path.

Kris

 

[Archer86]

At the same speed it's going to be the larger caliber. It's displacing more tissue and fluid at a faster rate because it's wider. Assuming same type of bullet performance and impact location being equal.

Nothing to do with energy.

Energy by definition is the ability of an object in motion to stay in motion.
It takes more the larger the frontal area of a bullet. So the larger that area the more weight the bullet needs to be to keep it driving forward.
Another interesting thing. The wide front on a bullet wants to stop it and the heavy shank behind it wants to pass it up. Much like a motor cycle hitting a stump. A faster twist will help the bullet not want to swap ends and continue a straighter path.

Kris

Ok will have to take a listen to that podcast. Last question if energy doesn't matter only velocity what pistol are you carry for protection in archery season in grizzly country?

 

[BjornF16]

That's not representing the charts above. A 115 grainn bullet going just over 1900fps and a 212 grain bullet going just over 1900fps at both at 800 yards which one causes more damage and why?

It depends…

If both bullets are “match bullets” say ELD-M, then the larger will cause “more damage”.

If the 115 is a match bullet and the 212 is a mono, then the smaller bullet will cause more damage and a quicker kill.

What matters is bullet construction, impact velocity and how that particular bullet behaves at that impact velocity.

The entire premise that @PNWGATOR stated with the .223 on big game thread is that bullet construction matters more than head stamp. With proper bullets in smaller caliber, a hunter can be just as, or even more, lethal than shooting a larger caliber with more recoil when you have a higher hit rate with the smaller caliber and the ability to spot your impact (and deliver follow on shots, adjusted if necessary, quicker than the higher recoiling rifle)