Struggling to see the point of 6.5's

[Axlrod]

This is the link to Litz's program:

AB Analytics Package - The Science of Accuracy

Applied Ballistics Analytics program for your computer - full suite of conventional ballistics features including WEZ (Weapon Employment Zone)

thescienceofaccuracy.com

 

[Formidilosus]

In your experience, with reduced recoil, what effect does a muzzle break or suppressor have on hit rates?

The brake helps quite a bit due to lowering recoil, but hurts quite a bit due to noise and concussion. A suppressor doesn’t reduce recoil as much as a brake, but greatly helps with sound, concussion, and recoil impulse. It seems to result in around a 20-30% reduction in ft-lbs recoil.

 

[Rick M.]

Don’t start unless you have about $2K to spend on a new Tikka, SWFA and a bunch of 77TMK’s!!!

You weren't kidding...

 

[280Ackley]

You weren't kidding...

Nope!! I was able to find a couple of loaded boxes ammo and I am researching how to upgrade AR to shoot them best!!

 

[Rick M.]

Nope!! I was able to find a couple of loaded boxes ammo and I am researching how to upgrade AR to shoot them best!! View attachment 484381

Nice! You selling your 280 AI?

 

[Macintosh]

My conclusion is that stipulating copper bullets turns the normal caliber debate completely upside down and reshuffles the deck.

according to barnes lrx data chart, if you use 2200fps impact velocity as a minimum as Im lead to believe I should be, 6cm and .270win (and I imagine 6.5prc although they dont provide data) are the only calibers they offer that even give you a 400 yard maximum range before stepping up to the bigger belted magnums, and they even best several of those in range before losing velocity. By that measure 6.5cm has a maximum effective range of about 325 yards according to this chart. Advantages are advantages, and Im sure many of these cartridges can be more or less hot-rodded, the point simply being that copper ammo and setting a minimum impact velocity for reliable expansion turns a lot of conventional wisdom on its head at least to a degree, especially for factory ammo.

Chart is at: https://www.barnesbullets.com/wp-content/uploads/2021/03/Barnes-VOR-TX-LR-Ballistics.pdf

 

[280Ackley]

Nice! You selling your 280 AI?

No way, I love that gun!!! I have yet to find a critter in Idaho that can survive the 168 VLD, from coyote to moose. I do see a lot of practice with the AR and possibly a Tikka in the future if they ever are available again! Between my kids and I, I would like to see how the 77TMK fair against them all too!!

 

[Rick M.]

My conclusion is that stipulating copper bullets turns the normal caliber debate completely upside down and reshuffles the deck.

according to barnes lrx data chart, if you use 2200fps impact velocity as a minimum as Im lead to believe I should be, 6cm and .270win (and I imagine 6.5prc although they dont provide data) are the only calibers they offer that even give you a 400 yard maximum range before stepping up to the bigger belted magnums, and they even best several of those in range before losing velocity. By that measure 6.5cm has a maximum effective range of about 325 yards according to this chart. Advantages are advantages, and Im sure many of these cartridges can be more or less hot-rodded, the point simply being that copper ammo and setting a minimum impact velocity for reliable expansion turns a lot of conventional wisdom on its head at least to a degree, especially for factory ammo.

Chart is at: https://www.barnesbullets.com/wp-content/uploads/2021/03/Barnes-VOR-TX-LR-Ballistics.pdf

I would agree. The copper monos seem to call for light-for-caiber at higher velocities, whereas traditional bullets seem to work best with heavy-for-caliber bullets at lower or normal velocities. I've always gravitated towards copper due to fears of lead contamination, especially with respect to my kids eating the meat that I procure. If not for that I'd likely try the TMK route.

 

[clperry]

I would agree. The copper monos seem to call for light-for-caiber at higher velocities, whereas traditional bullets seem to work best with heavy-for-caliber bullets at lower or normal velocities. I've always gravitated towards copper due to fears of lead contamination, especially with respect to my kids eating the meat that I procure. If not for that I'd likely try the TMK route.

You’ll never see the contamination in the real world as far as ingesting it goes. Wrong form of lead and not nearly enough of it. We aren’t raptors, different ball game for us. Most city dwellers that don’t eat wild game killed with lead projectiles show considerably higher levels of lead in their system than do hunters and fishermen. Ultimately, we all have to live with our own decisions, I understand that.
But based on empirical data, you can dump many rounds of traditional ammo into your big game and crush those sinkers with your teeth to your hearts desire.


Sent from my iPhone using Tapatalk

 

[Rick M.]

You’ll never see the contamination in the real world as far as ingesting it goes. Wrong form of lead and not nearly enough of it. We aren’t raptors, different ball game for us. Most city dwellers that don’t eat wild game killed with lead projectiles show considerably higher levels of lead in their system than do hunters and fishermen. Ultimately, we all have to live with our own decisions, I understand that.
But based on empirical data, you can dump many rounds of traditional ammo into your big game and crush those sinkers with your teeth to your hearts desire.


Sent from my iPhone using Tapatalk

I'm definitely open minded about it and willing to learn more. Do you happen to know of any peer-reviewed research on this? Thanks.

 

[JFK]

If you are going to shoot copper, shoot something that’s inherently fast and push them even faster if you handload (e.i not a creedmoor).

according to barnes lrx data chart, if you use 2200fps impact velocity as a minimum as Im lead to believe I should be, 6cm and .270win (and I imagine 6.5prc although they dont provide data) are the only calibers they offer that even give you a 400 yard maximum range before stepping up to the bigger belted magnums

The 270 can be loaded with lrx to be at 2200fps at 500 yards while staying within published loads.

 

[J Batt]

I'm not going to say anything here that hasn't already been said. I also believe, oftentimes, people ask questions looking for information to corroborate a conclusion they've already come to. But that's a different discussion for a different day.

IMO, what the 6.5's (specifically the creedmoor) bring to the table is incredible balancing of many different aspects of cartridge development.

1. It was designed, from the ground up, specifically to work with heavy for caliber bullets with high ballistic coefficient and high sectional density. There was already a "6.5" on the market (the .260 Rem), but it wasn't designed specifically to do this from day one. It was twisted wrong, and the case length and shape mean you have to eek into your powder space in order to seat the Heavy for Caliber bullets deeper than is ideal. The Creedmoor fixed some issues that the .260 didn't.

2. It's case shape was designed around the same principles, and the straight wall and 30 degree shoulder help to mitigate issues with case "growth" and simplify reloading processes. I've heard @Formidilosus say he doesn't trim his 6.5 brass, and it's the case design that means it's safe to do so. It does eventually grow, but not at the rate of a 7 rem mag or 280 or 270.

3. It's a lower recoiling round for it's trajectory. I think it's a common misconception that the 6.5 Creedmoor has a laser-beam like trajectory, and it just doesn't. The rifle I packed in colorado has a MV of 2630 FPS, and at 1000 yards (with a 100 yard zero), I drop about 8 mils. It's not a missile strike at all. My brother shoots a Weatherby Vanguard .270 Winchester that shoots Hornady factory Superformance BLISTERINGLY fast (about 3200 FPS), and he's only got about 6.5 mils of drop at 1k. However, our energy (per the Shooter App) at 1k is within 20 ft-lbs of eachother, and our wind drift is different by about .3 MILS, 10 MPH wind at 90 degrees relative to bullet flight path (advantage 6.5). The difference is the 270, moving almost 600 FPS faster, recoils considerably more to reach those numbers. I'm not talking painful recoil, I'm talking the type of recoil that doesn't move you a mile off target when shooting from a bag or off a pack. People talk about recoil as if it's a painful thing, and at points it can be (6 LB 300 Win Mag, for example). Personally, I'm with you OP, the -06 is where I feel I start to feel a really sharp dropoff in my ability to handle the rifle when it comes to recoil. HOWEVER, I had a .308 (Browning A Bolt II) for awhile and was pushing the 168 AMAX at about 2850 FPS, and even though it didn't hurt, it moved me off target significantly more than my 6.5 Creedmoors do (I've got 3 of them now) and was significantly more difficult to control. Again, not painful, just a significant increase in overall movemement. For their recoil and muzzle velocity, my creeds are extremely efficient and other rounds have to either be loaded hotter or be throated longer or twisted tighter in order to keep up. Again, they were designed from the ground up with those things already in mind.

Bottom line, the 6.5 Creedmoor didn't do any ONE thing that anything else on the market didn't already do when it was released. But it gave us a balanced combination of all those attributes (and many others) that no cartridge had before, and taught us that cartridges could actually be designed properly for inherent accuracy. The 6.5 PRC does the same thing but on a "hotter" level. Lots of the other modern 6.5's apply these same principles in order to increase performance marginally, but then you start getting into issues with barrel life and such. It's not that the 6.5's are necessarily anything magical in and of themselves, it's that several of them have been designed in modern times for our modern understanding of ballistics and performance.

I would argue that some, like the 6.5-300 Weatherby or the 26 Nosler, are just downright stupid and pointless. But that's more a dig on the cartridge design than the 6.5mm bore diameter.

Can you push a 180 GR. ELDM from a 280 AI or a 7 Rem Mag if you're a proficient handloader? How about a 230 Grain ATIP from a 300 Win Mag or a 308? Absolutely, without question. But were those cartridges designed, from the ground up, to do that? Nope, not even a little bit.

The 6.5's aren't magical, they just were the bore diameter that Hornady chose to start with when we started into this renaissance of modern ballistics. If they had come out with the 25 Creedmoor or the 7 Creedmoor at the time, you'd have probably started a thread about "What's magic about the 25's" or something. The things companies learned in developing and designing and building rounds like the 6.5 Creedmoor and PRC lead to rounds like the 300 PRC (applies all the same relative balance points to a cartridge that smears the 300 Win Mag across the pavement), the 6.8 Western, the 7 PRC, and I'm sure many more to come.

Bottom line, 6.5 isn't special in and of itself. The modern cartridges they tend to adorn are what's special.

But hey, I'm just some random guy on the internet...

Ron Spomer?

 

[sbaker0029]

Can I get the footnotes on what happened from page 8 to 13? Lol
I work nights went to bed at about 7:30am yesterday and just got back to the post, seems like a lot has gone on and I don't want to miss anything

 

[Rob5589]

Shoot whatever you want
Bullets not headstamps
6CM is better

 

[Darryle]

Shoot whatever you want
Bullets not headstamps
280 Ackley is better

FIFY

 

[PredatorSlayer]

You’ll never see the contamination in the real world as far as ingesting it goes. Wrong form of lead and not nearly enough of it. We aren’t raptors, different ball game for us. Most city dwellers that don’t eat wild game killed with lead projectiles show considerably higher levels of lead in their system than do hunters and fishermen. Ultimately, we all have to live with our own decisions, I understand that.
But based on empirical data, you can dump many rounds of traditional ammo into your big game and crush those sinkers with your teeth to your hearts desire.


Sent from my iPhone using Tapatalk

Thank you. I have read the same. People who buy into this narrative that lead based bullets are going to poison themselves and their family are the same ones who ran out to get the jab without doing research. Mono manufacturers like that tool at hammer bullets is pushing this false narrative because its good for business.

 

[Newtosavage]

My conclusion is that stipulating copper bullets turns the normal caliber debate completely upside down and reshuffles the deck.

according to barnes lrx data chart, if you use 2200fps impact velocity as a minimum as Im lead to believe I should be, 6cm and .270win (and I imagine 6.5prc although they dont provide data) are the only calibers they offer that even give you a 400 yard maximum range before stepping up to the bigger belted magnums, and they even best several of those in range before losing velocity. By that measure 6.5cm has a maximum effective range of about 325 yards according to this chart. Advantages are advantages, and Im sure many of these cartridges can be more or less hot-rodded, the point simply being that copper ammo and setting a minimum impact velocity for reliable expansion turns a lot of conventional wisdom on its head at least to a degree, especially for factory ammo.

Chart is at: https://www.barnesbullets.com/wp-content/uploads/2021/03/Barnes-VOR-TX-LR-Ballistics.pdf

I study the ballistics charts pretty hard since I switched to monos. My 120 TTSX's were coming out of my 20" 7mm-08 barrel at 3150(ish) using CFE 223. At the altitude and weather conditions I normally hunt in during my trips out west, those bullets are still traveling at 2350 fps at 500 yards.

If I were hunting lower elevations then that range would of course be reduced.

When I look at the 6.5 PRC, I could expect (according to the Barnes load data) about 3050 fps. with their 127 LRX. That takes me to 2400 fps. at 500 yards.

Not a lot of difference between them, even though the 120 TTSX has a measly 0.37 BC.

This is part of why I ask, what am I missing.

 

[Newtosavage]

Thank you. I have read the same. People who buy into this narrative that lead based bullets are going to poison themselves and their family are the same ones who ran out to get the jab without doing research. Mono manufacturers like that tool at hammer bullets is pushing this false narrative because its good for business.

I think we've already heard above that if you prefer monos, the 6.5 CM is not your cartridge. I agree and I'm moving on. Please feel free to do the same with the lead vs. mono debate. Those of us who prefer monos have our reasons just like those who choose to avoid the jab.

 

[Macintosh]

You must be hunting at much higer elevation than me, if I take my 7-08 ttsx load that I shot for years, even if I plug in 3150fps (I shoot factory and am not even getting 3000fps) my strelok app says I’m barely getting 400 yards before running out of velocity. I think you have a “souped up” 7-08 given your velocity—so you need to compare to a “souped up” version of every other catridge to get a balanced comparison.
Regardless, you hit on the same thing I recently did—if you already have a 7-08, 6.5 may have some advantages even for copper but not enough to call them significantly different. However, if one were to start from scratch looking for “the” one cartridge to fill that niche—ie you dont already have a 7-08 or similar—6.5 might make more sense. I recently did exactly this—i needed to rebarrel my 7-08. 6.5 was an option and it probably has among the best ammo availability but looked anemic for copper, 7-08 was an option but has reduced range with factory ammo and is hard to find at times. I like the 6.5prc on paper but I shoot factory ammo, had a std bolt face and wanted better than average availability. I ended up going with a 270 specifically to get a bit more velocity and for ammo availability. Rangewise Sounds like it will perform with your hot-rodded 7-08.

 

[Rob5589]

I study the ballistics charts pretty hard since I switched to monos. My 120 TTSX's were coming out of my 20" 7mm-08 barrel at 3150(ish) using CFE 223. At the altitude and weather conditions I normally hunt in during my trips out west, those bullets are still traveling at 2350 fps at 500 yards.

If I were hunting lower elevations then that range would of course be reduced.

When I look at the 6.5 PRC, I could expect (according to the Barnes load data) about 3050 fps. with their 127 LRX. That takes me to 2400 fps. at 500 yards.

Not a lot of difference between them, even though the 120 TTSX has a measly 0.37 BC.

This is part of why I ask, what am I missing.

Something has to be off on the PRC. I run a straight from Barnes load 7/08 with the 120 at 3150. The PRC has to be doing a couple hundo faster with a 127.