Struggling to see the point of 6.5's

[Mule3006Elk]

I'm struggling with choosing between the .264 and the .284 myself at the moment. I am really on the fence between the 6.5 CM, 7mm-08, and .280 AI for my next rifle / handloading project.

I'm planning to use either Barnes or Hammer bullets (I prefer lead-free). From what I'm seeing, at the lighter weight projectiles (which seem to be preferred when using copper / mono), the .264 bullets seem to have better BC and SD values. I'd have to go all the way up to the 168g LRX (.284) with Barnes before surpassing the SD and BC of the 127g LRX (.264). Now, I'm not too concerned with the BC because I plan on keeping my shots 450 and in.

My goal is to get as close as I can to 3k MV with a non-magnum out of a 22" barrel. I don't think the CM can do it, the 7mm-08 comes close, and the .280 AI can easily do it with the lighter bullets (but not the 168 grain and up class of bullets).

I love the .280 AI for the cool factor as well, and am not really interested in the upcoming 7 PRC or 7 Rem Mag.

I don't believe a game animal will notice the difference between a .260 SD bullet and a .248 SD bullet, but it still factors in.

280 AI has my vote. Run it full tilt or back off velocity if needed. Can make the 280 AI run 7mm-08 velocity but not the other way around. 145 grain bullet will be running 3000-3100 fps, bigger hole, no concern about is it enough. Really can be a do-it-all cartridge in NA.

Hammer bullets, shot one deer thus far, 30 cal, did it's job, meat saver shot so no bang/flop but didn't go far. You can push those bullets on average about 100 fps over max as listed by Barnes for similar weight (per Steve).

 

[Rick M.]

280 AI has my vote. Run it full tilt or back off velocity if needed. Can make the 280 AI run 7mm-08 velocity but not the other way around. 145 grain bullet will be running 3000-3100 fps, bigger hole, no concern about is it enough. Really can be a do-it-all cartridge in NA.

Hammer bullets, shot one deer thus far, 30 cal, did it's job, meat saver shot so no bang/flop but didn't go far. You can push those bullets on average about 100 fps over max as listed by Barnes for similar weight (per Steve).

Very true, I love how efficient the 7mm-08 is (only 40-50 grains of powder), but you're absolutely right, once you hit that limit, that's it. The 280 AI gets you to the next level without going magnum. It's another significant jump in powder from 280AI to 7RM or 7PRC for minimal velocity gains. I'm likely going to grab a Weatherby Backcountry and then start waiting for Peterson to do another run of the 280 AI brass.

Lastly, I just have a crush on the Ackley Improved stuff. There's just something about it. I think having a 25-06 AI and a 280 AI would leave me completely content for the rest of my life.

Thanks for that data on the Hammer stuff, too. Steve is getting over 3300 MV with a 22" barrel 280AI with the 140g absolute hammers. That's just insane, and I love it.

Source: https://hammerbullets.com/product/284-cal-140g-absolute-hammer/

 

[Formidilosus]

The hit rate between a 7mm-08 and a 6.5 CM with like BC Barnes LRX bullets is within .5% at 400 yards in field conditions, (12” target, 4mph wind caller, the best ammo and gun made for true 1 MOA ES)

78% hit rate with both at 2950fps- (impact velocity of 2,172fps (marginal terminal performance from these bullets)



This is why BC matters- 91% with a 147gr ELD-M from a 6.5 CM 2,725fps (impact velocity 2,220fps very good terminal performance)




Now let’s look at a Barnes mono and see if we can even match the hit rate of the 6.5cm with any combination in the 7mm-08, to do so we have to use the 168gr LRX at 2,600fps which gives us a 78% hit rate.. the slight increase in BC at 400 yards created a wash from the lower MV (and 1,990fps impact, which results in expansion below what almost anyone would find acceptable)




No matter how slice it, there is no advantage to the 7-mm08 when using monos. And, the only advantage to the 6.5 cm when using monos is 15% less recoil.

 

[Formidilosus]

Man, nothing sets Rokslide on fire like a guy just questioning the greatness of the mighty 6.5.

Is that reality? Can you please point out anyone in this thread that is objectively doing what you stated? Who has said anything remotely close to “the greatness of the mighty 6.5”? The OP asked for what he missing, and people are replying with exactly what he is missing, generally with facts.

 

[Formidilosus]

Now, for some more reality.

One can shoot the best bullets in a 7mm-08 and match the hit rate of the 6.5/147gr combo at 400 yards. The 180gr ELD-M at 2,500fps has a 91% hit rate, with more than 18ft-lbs of recoil (8lb rifle)-



So to just match the 6.5cm with a 7mm-08 you get a “gift” of 21% more recoil.


I’m about objective reality- I do not do “I like, I think, I feel” nonsense. The reality of why any good 6.5 (or 6mm), shooting good bullets is popular is due to what they factually do. The 6.5cm just happens to be the one that came to market designed correctly and was supported correctly first.

 

[Rick M.]

The hit rate between a 7mm-08 and a 6.5 CM with like BC Barnes LRX bullets is within .5% at 400 yards in field conditions, (12” target, 4mph wind caller, the best ammo and gun made for true 1 MOA ES)

78% hit rate with both at 2950fps- (impact velocity of 2,172fps (marginal terminal performance from these bullets)
View attachment 484140


This is why BC matters- 91% with a 147gr ELD-M from a 6.5 CM 2,725fps (impact velocity 2,220fps very good terminal performance)

View attachment 484166


Now let’s look at a Barnes mono and see if we can even match the hit rate of the 6.5cm with any combination in the 7mm-08, to do so we have to use the 168gr LRX at 2,600fps which gives us a 78% hit rate.. the slight increase in BC at 400 yards created a wash from the lower MV (and 1,990fps impact, which results in expansion below what almost anyone would find acceptable)

View attachment 484167


No matter how slice it, there is no advantage to the 7-mm08 when using monos. And, the only advantage to the 6.5 cm when using monos is 15% less recoil.

Thanks, Form. Always appreciate your wisdom. That software looks pretty nifty.

For copper monos specifically, would the 6.5 PRC be a better consideration alongside the 280AI? (For staying above that 2200 mark for terminal performance)?

 

[Titan_Bow]

From a practical hunting perspective, I look at all these short action calibers as pretty similar. It is interesting to see how forum talk makes one seem so much greater or lesser than another. I own a 6.5 Creedmoor, but the reason I bought it, was because I didn't already have a 308 or 7mm-08. I needed a rifle that my 12 year old could take on a cow elk hunt. My other short action rifle was a 270WSM, which is way more recoil than my son could handle.
SO, I looked at ballistics, recoil, bullet selection, etc. and for me and my purposes, I felt the 6.5CM was the best option. My son dumped a big cow that year at 200 yards, and she dropped right there.
If I were rebarreling my Savage short action and recoil wasnt a consideration, I would maybe look at a short action magnum. I've been considering rebarreling my 270WSM, updating it to 6.8 Western, or maybe 300WSM or 7WSM. Maybe if I wanted new and shiny, playing around with that new 277 Sig Fury.

 

[z987k]

The hit rate between a 7mm-08 and a 6.5 CM with like BC Barnes LRX bullets is within .5% at 400 yards in field conditions, (12” target, 4mph wind caller, the best ammo and gun made for true 1 MOA ES)

78% hit rate with both at 2950fps- (impact velocity of 2,172fps (marginal terminal performance from these bullets)
View attachment 484140


This is why BC matters- 91% with a 147gr ELD-M from a 6.5 CM 2,725fps (impact velocity 2,220fps very good terminal performance)

View attachment 484166


Now let’s look at a Barnes mono and see if we can even match the hit rate of the 6.5cm with any combination in the 7mm-08, to do so we have to use the 168gr LRX at 2,600fps which gives us a 78% hit rate.. the slight increase in BC at 400 yards created a wash from the lower MV (and 1,990fps impact, which results in expansion below what almost anyone would find acceptable)

View attachment 484167


No matter how slice it, there is no advantage to the 7-mm08 when using monos. And, the only advantage to the 6.5 cm when using monos is 15% less recoil.

That's some interesting software.
From the visual representation of the spread, what it looks like is the higher BC compensates for a missed wind call better and that's about it? Extra velocity can also compensate for wind drift to a point.
What happens when the 125gr 6.5cm mono has a BC of .590 moving 200fps faster than it can push the 147eldm?

 

[Formidilosus]

Thanks, Form. Always appreciate your wisdom. That software looks pretty nifty.

The WEZ is awesome for removing feelings and seeing reality. If correct data is entered, it’s fantastic.

For copper monos specifically, would the 6.5 PRC be a better consideration alongside the 280AI? (For staying above that 2200 mark for terminal performance)?

I mean yes, but the increase in recoil is the cost. I’m not speaking to “it hurts”, I’m speaking about the cost in shootability, which is hit rates- there is no magic, as recoul goes up, shootability goes down. And there are some good projects that has shown there seems to be some kinda hard limits on it. A better way to get good performance from monos is to drop calibers. For instance, a 6cm and a 22CM using Barnes LRX bullets has the same hit rate, actually higher due to more shootability, and high impact velocities at medium range than either the 6.5 or 7mm-08, with nearly identical terminal performance being that they are monos.

 

[Formidilosus]

That's some interesting software.
From the visual representation of the spread, what it looks like is the higher BC compensates for a missed wind call better and that's about it? Extra velocity can also compensate for wind drift to a point.

BC compensates greatly for wind- it’s by far the biggest factor in wind drift. MV only helps at ranges that really are the easiest to judge wind at.

What happens when the 125gr 6.5cm mono has a BC of .590 moving 200fps faster than it can push the 147eldm?

What 6.5 mono has a BC of .590?

 

[z987k]

BC compensates greatly for wind- it’s by far the biggest factor in wind drift. MV only helps at ranges that really are the easiest to judge wind at.




What 6.5 mono has a BC of .590?

The Badlands Bulldozer 2.

 

[z987k]

BC compensates greatly for wind- it’s by far the biggest factor in wind drift. MV only helps at ranges that really are the easiest to judge wind at.

Right, what I'm more interested in is how that software is coming to it's conclusions. Is it proprietary? I'm not seeing it readily available via google.

 

[nobody]

Right, what I'm more interested in is how that software is coming to it's conclusions. Is it proprietary? I'm not seeing it readily available via google.

Home - Applied Ballistics

appliedballisticsllc.com

There you go sir

 

[Mule3006Elk]

Lastly, I just have a crush on the Ackley Improved stuff. There's just something about it. I think having a 25-06 AI and a 280 AI would leave me completely content for the rest of my life.

100% agree.

I run a 30-06 with 150 grain 3100 fps and 175 grain at 2830 fps. I run a 300 WM 150 grain 3300 fps and 175 grain ~ 3015 fps.

Never ask myself is this enough gun.

 

[z987k]

Home - Applied Ballistics

appliedballisticsllc.com

There you go sir

What browser do you run that on? I just tried 3 and it just delivers a blank page when you hit calculate.

 

[Rick M.]

What browser do you run that on? I just tried 3 and it just delivers a blank page when you hit calculate.

Same for me. I'm using Firefox.

 

[Formidilosus]

The Badlands Bulldozer 2.

Ah. That what I thought. Ignoring the terminal performance difference, the hit rate is 88% with 2,310fps impact at 400 yards-

Right, what I'm more interested in is how that software is coming to it's conclusions. Is it proprietary? I'm not seeing it readily available via google.

You have to buy the software. Brian Litz’s deal. Applied Ballistics Weapon Emoloyment zone. It uses a 6 dof program with the variables that are seen on the left hand side and the input bullet data to project a statistical probability of a first round hit for a given scenario.

AB WEZ explanation

 

[Newtosavage]

Man, nothing sets Rokslide on fire like a guy just questioning the greatness of the mighty 6.5.

Sent from my SM-G990U using Tapatalk

Apparently some people struggle with the idea that a person can ask an honest question without already having their mind made up. Probably projecting.

I'd still like to hear more about the 6.5 PRC. I've essentially ruled out the CM by now and the thread was never about the CM specifically. It was about 6.5 bore cartridges vs. 7's and others.

 

[WeiserBucks]

I'd still like to hear more about the 6.5 PRC.

PRC will be faster than many other 6.5s available, factory ammo is good but can be hard to find at times, same with reloading supplies. It's a good choice if you want a 6.5 that is faster than a Creed but easier on everything than a 26 Nosler.

 

[sndmn11]

The WEZ is awesome for removing feelings and seeing reality. If correct data is entered, it’s fantastic.




I mean yes, but the increase in recoil is the cost. I’m not speaking to “it hurts”, I’m speaking about the cost in shootability, which is hit rates- there is no magic, as recoul goes up, shootability goes down. And there are some good projects that has shown there seems to be some kinda hard limits on it. A better way to get good performance from monos is to drop calibers. For instance, a 6cm and a 22CM using Barnes LRX bullets has the same hit rate, actually higher due to more shootability, and high impact velocities at medium range than either the 6.5 or 7mm-08, with nearly identical terminal performance being that they are monos.

Could you run whatever numbers you run VS the 6.5creed for a 6 creed? It seems high BC at high velocity while staying under X recoil threshold is the winner for hit probability. So, in Colorado a good big game choice for hit probability might be a 115 Berger from a 6creed VS a 6.5creed load of similar recoil?

Also, I am curious how those same bullets from your 6.5creed screenshots probability compares when velocity increases say for 6.5PRC, 6.5-300 etc., or decreases 6.5br, 6.5grendel, etc. I am certain there's intersection where velocity/recoil helps and where it becomes detrimental.