Gun-Reck
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New and old cartridges doing (nearly) the same
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Gun-Reck
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And that's why it's a toy.
snowman357
Member
A lot of the new cailbers are so close to something that has been on the market for years, I look at them as marketing scams. Just change the velocity by 200 fps subtract 20 grains and give it a marketing name like 247 zipper, 45 buzz saw or 6.5 hot rod. Hey 6.5 hot rod surely we need another 6.5 option. Lots of new cailbers over the years but no real innovation.
CraigC
Sixgun Nut
A toy the military is using to shoot people with.
The goal is not deader. Never was. The goal is flatter trajectory and less wind drift.
Only a Fudd thinks that makes it a toy.
Anchorite
Member
The only innovation may just be in powders first, bullets secondly. But the brass bottle launcher? Naww.
Gun-Reck
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Jim Watson
Member
If Mr Stoner were Swedish, the AR-10 would shoot 6.5x55.
If the Army hadn't got hung up on using WW I leftover .30, it would shoot .276.
But the installed base mean the ammo companies serve the rifle makers.
If the Army hadn't got hung up on using WW I leftover .30, it would shoot .276.
But the installed base mean the ammo companies serve the rifle makers.
CraigC
Sixgun Nut
As I said, try reading the thread.
Risky buisness
Member
Hey this is fun. I presume it's just fine to have an opinion here...... as long as its just one guy that has it, and everyone else has to agree....or your a fudd...... As I remember from some time ago, fudd, boomer, insults regarding comprehension wouldn't be tolerated here. I probably have engaged in that too, taken up in the argument, that certainly doesn't make it right and i tire of having to use the ignore button. This thread is moderated,....... right?
Gun-Reck
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This thread?
New and old cartridges doing (nearly) the same
The 6.5 CM is a toy, born and bred, to poke holes in paper for fun and prizes.
It shoots the same bullets, at the same velocities, as the 6.5x55mm, a military cartridge developed in 1893.
It just may be infinitesimally more precise.
Again, how does it kill better?
mcb
Member
Question, can you put 6.5x55 Swiss into the existing M40 or M110? The answer is no, but with a simple barrel change either of those platforms will run 6.5 Creedmoor, using the same 308 bolt, and magazine. Sometimes it's not about the down range performance but bring a particular performance envelope to a proven platform. So yes it does not kill better than 6.5x55 but from a logistical point of view 6.5 Creedmoor is considerable more palatable to the US military than 6.5x55mm. Logistics trumps almost anything else on the battlefield.
On paper the Tiger Tank was far superior to the M4 Sherman is almost everyway that mattered, even on the real world battlefield it was superior in may ways, except for the most important spec logistics. Logistically we were able to put 50,000+ M4 on the battlefield and only 1347 Tigers ever existed.
mcb
Member
No it does not bring anything new but it does shoot slightly flatter and carry slightly more energy down range than 7.62x51mm and was a relatively easy retrofit into existing military platforms like the M40 and M110. That slightly performance increase might make it kill better because it might make it easier to hit with and hit slightly harder at longer ranges compared to 7.62x51mm. Thus the reason the military was playing with it see if those modest performance increases pan out on the battlefield. They are not playing with 6.5x55mm...
Who knows 6.8×51mm Common Cartridge might replace them both...
Logistic says were are staying with 5.56x45mm and if I was a betting man that is were my money would be...
There has been a trend towards extreme accuracy uber allis. The current crop of short, straight, stubby rifle cartridges have replaced old standards for long range shooting, because the newer cartridges do produce lower velocity spreads at distance. One of my F Class buds showed me chronograph data at the 1000 yard target. His extreme spreads at the target were under 20 fps, very impressive.
However, the target shooters are firing single shot. A number of them don't have an ejector on the rifle, they just tip the round out with their finger. Straight cartridges don't feed well, they are single stack, and the stack can't be too tall. Just look at the feed angles from this magazine. Sure looks like a jam in the making
the Swiss K31 has more taper than a 308 Win, and so the round can be double stacked for more magazine capacity than what Winchester did for their M70. The 308 is very straight and has to be more precisely aimed at the chamber. This reduces magazine capacity.
this is a good example of the problems of very straight cartridges, the 450 Bushmaster. There is a reason no one sells magazines greater than five rounds, and even those with five round magazines have to tinker with things to achieve reliable feed.
Feed and extraction were extremely important considerations for WW1 era military cartridges. Look at the 303 Brit cartridge (and the 300 H&H Magnum), those cartridges are like darts. They steer very well into the chamber, don't drag. Sharp shoulders bump and will jam on the way in, which is why for older cartridges, the shoulders have a lot of taper. And those cartridges operated around 40 kpsia. Pressure causes problems, more pressure causes more problems. For a cartridge to be used World Wide, the soldier can be deployed to the Aleutians, or to Iraqi. Temperature extremes are easily -40 F to +120 F. I am very concerned about the US Army deploying a 80 Kpsia cartridge, that is ungodly high pressure. The older cartridges, running around 40 kpsia gave more margin, stressed the weapon less (requiring cheaper grades of steel), and they worked. Sure they took more powder, but powder technology was less advanced.
However, feed and extraction don't seem to be all that important anymore. As long as you can tip the cartridge out with a finger, a single shot action is just fine.
This is a well designed cartridge, the Chinese 5.8. Lots of taper, thick extractor rim, steel case, operates in the 40 kpsia range. If anyone has noticed, brass requires a lot of copper, and copper is getting hard to find. Designing a cartridge from the start around steel is smart. Anyone who has experienced jams with steel case in AR's can understand that an action, and cartridge that relies on brass as a material, does not transition well to steel.
Just take a look at the book Cartridges of the World, and point out a cartridge gap within a class.
Cartridges are introduced primarily to increase Corporate profit. User need is often some contrived story. Modern CNC manufacturing technology makes hardware changes simple and cheap. Cartridges are now a fashion trend. In today, out tomorrow. As an example of the triviality used to justify a new cartridge and rifle. I recently read about the introduction of another best ever cartridge (i think it was the 7mm PRC) and the cartridge maker had changed the cartridge dimensions just a little bit, so an earlier version with a different bullet would not chamber in the new rifle. Basically, when a new bullet comes out, an entirely new cartridge case and rifle are being introduced. Live long enough, and you will see a lot of end of time bullets go on the ash heap of history. You can read the press on the 7 mm PRC, it is touted as the best 7mm ever. The differences between it, and all the others, are less than thickness of card stock. But in print, WOW! what a major accomplishment! The improvements are greater than the width of the Grand Canyon. Whoppee!
I am sure a lot of buyers ran screaming to the Local Gun Store. I will advise those who purchase the cartridge du jour: buy a lot of brass. In ten years, when runs between lots are seven years, try to sell a rifle when there is not any new brass or cartridges on the shelves. There are a lot of older, great cartridges in this category. Took about 7 to 10 years to find new 257 Roberts brass. Scalpers snapped it all up and I had to pay confiscatory prices on Gun Broker. Well, first piggie to the trough got it all. That's life. But I did get new brass.
You know, I am very happy with my 308 Win, 30-06. These were, and are, great cartridges. And there is lot of brass and components. The 223 Rem, have not shot one in a decade now, but it shoots well. And there is always brass on the ground at the range. That is good for longevity.
However, the target shooters are firing single shot. A number of them don't have an ejector on the rifle, they just tip the round out with their finger. Straight cartridges don't feed well, they are single stack, and the stack can't be too tall. Just look at the feed angles from this magazine. Sure looks like a jam in the making
the Swiss K31 has more taper than a 308 Win, and so the round can be double stacked for more magazine capacity than what Winchester did for their M70. The 308 is very straight and has to be more precisely aimed at the chamber. This reduces magazine capacity.
this is a good example of the problems of very straight cartridges, the 450 Bushmaster. There is a reason no one sells magazines greater than five rounds, and even those with five round magazines have to tinker with things to achieve reliable feed.
Feed and extraction were extremely important considerations for WW1 era military cartridges. Look at the 303 Brit cartridge (and the 300 H&H Magnum), those cartridges are like darts. They steer very well into the chamber, don't drag. Sharp shoulders bump and will jam on the way in, which is why for older cartridges, the shoulders have a lot of taper. And those cartridges operated around 40 kpsia. Pressure causes problems, more pressure causes more problems. For a cartridge to be used World Wide, the soldier can be deployed to the Aleutians, or to Iraqi. Temperature extremes are easily -40 F to +120 F. I am very concerned about the US Army deploying a 80 Kpsia cartridge, that is ungodly high pressure. The older cartridges, running around 40 kpsia gave more margin, stressed the weapon less (requiring cheaper grades of steel), and they worked. Sure they took more powder, but powder technology was less advanced.
However, feed and extraction don't seem to be all that important anymore. As long as you can tip the cartridge out with a finger, a single shot action is just fine.
This is a well designed cartridge, the Chinese 5.8. Lots of taper, thick extractor rim, steel case, operates in the 40 kpsia range. If anyone has noticed, brass requires a lot of copper, and copper is getting hard to find. Designing a cartridge from the start around steel is smart. Anyone who has experienced jams with steel case in AR's can understand that an action, and cartridge that relies on brass as a material, does not transition well to steel.
Just take a look at the book Cartridges of the World, and point out a cartridge gap within a class.
Cartridges are introduced primarily to increase Corporate profit. User need is often some contrived story. Modern CNC manufacturing technology makes hardware changes simple and cheap. Cartridges are now a fashion trend. In today, out tomorrow. As an example of the triviality used to justify a new cartridge and rifle. I recently read about the introduction of another best ever cartridge (i think it was the 7mm PRC) and the cartridge maker had changed the cartridge dimensions just a little bit, so an earlier version with a different bullet would not chamber in the new rifle. Basically, when a new bullet comes out, an entirely new cartridge case and rifle are being introduced. Live long enough, and you will see a lot of end of time bullets go on the ash heap of history. You can read the press on the 7 mm PRC, it is touted as the best 7mm ever. The differences between it, and all the others, are less than thickness of card stock. But in print, WOW! what a major accomplishment! The improvements are greater than the width of the Grand Canyon. Whoppee!
I am sure a lot of buyers ran screaming to the Local Gun Store. I will advise those who purchase the cartridge du jour: buy a lot of brass. In ten years, when runs between lots are seven years, try to sell a rifle when there is not any new brass or cartridges on the shelves. There are a lot of older, great cartridges in this category. Took about 7 to 10 years to find new 257 Roberts brass. Scalpers snapped it all up and I had to pay confiscatory prices on Gun Broker. Well, first piggie to the trough got it all. That's life. But I did get new brass.
You know, I am very happy with my 308 Win, 30-06. These were, and are, great cartridges. And there is lot of brass and components. The 223 Rem, have not shot one in a decade now, but it shoots well. And there is always brass on the ground at the range. That is good for longevity.
CraigC
Sixgun Nut
Has nothing to do with agreeing or disagreeing. It as to do with the nature of the argument. I don't use terms like that lightly but when you're completely oblivious to the facts of the issue, I don't know how else to characterize it. And nothing I have to say on the subject hasn't already been posted in this thread and many others. I detest having to do so but I'm about to repeat myself......one more time. Hence the comment about reading comprehension. It's all been written before, right here, one needs only to READ IT.
I will repeat. It is a rifle cartridge designed for a specific purpose. Making things deader was not among the laundry list of jobs it needed to accomplish. This is from post #35:
"There aren't going to be any revolutionary changes with metallic cartridges, only incremental improvements. Not every improvement is intended to make deer deader, which always seems to be the question people ask. The 6.5CM was not designed for hunting. It was designed to do what the 6.5x55 and .260 cartridges did in a short action that fits the AR10 magazine, operates at higher pressure than the Swede and uses a faster standard twist than the dead .260. Other minor improvements were made but the cartridge was designed for long range target shooting. So folks could buy an off the shelf, affordable rifle and be relatively competitive in PRS."
It kills the same things just as dead as a whole slew of other cartridges. No one ever said it did anything different in that regard but that was also never its intent. If that is your measuring stick, you're using it where it doesn't apply.
You can say you have no interest in the things it does better than its predecessors. You can say they have no bearing on whatever shooting you do. You cannot, however, say they do not exist. Because they do. You are entitled to your opinion but so far, your opinion is not congruent with reality. The parameters included fitting the AR10 platform, which the Swede does not. Having more precise standard dimensions and operating at higher pressure than the Swede. It also included a faster standard twist than the .260 and a better case configuration for heavier bullets. Part of the goal was off the shelf rifles and off the shelf ammo that could compete in 1000yd competitions. It does all of those things and more. Those are facts. Not opinion and not hype. You can call it a toy all you want, for whatever absurd and arbitrary reasons but those are the facts and your opinion does not change that.
Risky buisness
Member
Craig. .....this is why I have decided to leave the elephants in our rooms alone. You and I have disagreed in the past, ok, thats how this goes.
However, when things get a bit heated or someone's golden calf gets skewered, we lose credibility with being drawn in. I am not aiming this at you, or anyone else here......this is a generality we all fall into. I would much rather have a thoughtful discussion, pro and con than participate in where many of our discussions end up, usualy leaving great information unsaid, un learned. So Let me start.......
If in any way If have insulted a member here in the past, my apologies.
Lets hope we could all, despite differences try a bit harder and respect others opinions.
However, when things get a bit heated or someone's golden calf gets skewered, we lose credibility with being drawn in. I am not aiming this at you, or anyone else here......this is a generality we all fall into. I would much rather have a thoughtful discussion, pro and con than participate in where many of our discussions end up, usualy leaving great information unsaid, un learned. So Let me start.......
If in any way If have insulted a member here in the past, my apologies.
Lets hope we could all, despite differences try a bit harder and respect others opinions.
Gun-Reck
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It's a toy, for punching holes in paper.
That it does or doesn't fit into this or that platform - is irrelevant, just drift.
Read the OP.
How does it kill better than the 129 year old 6.5x55mm?
mcb
Member
If 6.5 CM is a toy then does that mean 6.5x55 is a toy? Their external and terminal ballistics are nearly identical?
You keep trying to avoid the differences but there are allot of little things that 6.5 CM does that are incrementally better then 6.5 x55. Due to 6.5 CM's smaller case volume and higher operating pressure it uses propellant more efficient and results in slightly less propellant and recoil for the same velocity and bullet weight. It fits in modern proven and more ergonomical platforms that are lighter to carry. Has more room for and better twist rate for modern VLD bullets. None of these are huge improvements but as a whole adds up to a cartridge and gun that is more accessible and more shootable than the 6.5x55 and this results in a gun that is easier to achieve hits and hits are 90% of killing whether that is hunting or combat. No one is saying 6.5 CM is night and day different but allot of people think the totally of those minor improvements are worth it on the range, in the woods, and on the battle field. The US military agrees to a fair degree with some special units running AR-10s, SR-25s, and Mk 48 machineguns in 6.5 CM. Conversely no one is fielding 6.5x55 since the Sweden stopped in 1995...
So you can think it's a toy all you want...
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CraigC
Sixgun Nut
It's a rifle cartridge for long range shooting competition. It's now a DMR cartridge used by the military. In other words, for killing the enemy.
One more time, with different words. You're judging a cartridge by standards it was never intended to meet.
Fitting into a specific platform 100% relevant. As that was its purpose. Not killing anything deader than any other cartridge. Shooting flatter than the .308 was also its purpose. Not killing anything deader than any other cartridge. Fitting into a shorter magazine than the 6.5x55 was its purpose. Not killing anything deader than any other cartridge. Shooting heavier bullets than the 260 is its purpose. Not killing anything deader than any other cartridge.
Killing anything deader than any other cartridge is not its purpose.
Your broken record argument has no merit and no substance. Or maybe you're too obtuse to understand the differences. I don't know.
Jim Watson
Member
Wow, adventures in logistics, keeping these Special units supplied with their Special ammo because they are Special. And I am sure that even Specialer units will get the 6.8mm More Specialer Than Ever guns to feed. While Ordinary units still need Ordinary ammo, both kinds, 7.62 and 5.56.
mcb
Member
Special forces have had discretion to step outside of standard supplies lines when missions called for it for as long as there have been special forces. It's very much part of what they do.
But it doesn't shoot as flat as the .300WM. Maybe almost as flat, depending on your definition of almost. Just a quick comparison using Barnes Vor-TX ammo published data, both with TTSX bullets:
6.5CM: 120 gr TTSX, SD = 0.246, BC = 0.412, MV = 2910, Drop at 500 yards (w/ 200 yd zero) = -43.8"
.300WM: 165 gr TTSX, SD = 0.248, BC = 0.442, MV = 3120, Drop at 500 yards (w/ 200 yd zero) = -36.3"
So, shooting the same bullet design with nearly identical SD, the 6.5CM drops 21% more at 500 yards and the difference will only get bigger as the range increases since the .300WM is pushing a higher BC bullet with a higher MV.
The 6.5CM will have substantially less recoil and the ballistics are very good, but it is no way, no how as flat shooting as the .300WM.
WOW did I go to ARCOM instead of The High Road????? This forum sure has slipped in the last couple of years.
As far as old versus new cartridges goes here is my take. If I had a rifle in an older caliber then I would just keep using it. Just like I do with my Enfield SMLE. But if I am buying new in a different caliber, then I am going to look at everything available and go with what suits my needs the best. And that is why my last centerfire AR build is a 6 ARC. I wanted something that is good for precision shooting and that I can still use ethically for deer hunting. And both the 303 and 6 ARC will kill a deer just the same. But I am not going to use the Enfield SMLE for a lengthy range session, my bad shoulders won't hold up to that. I can shoot the 6 ARC all day long without any issues.
Since I have bad shoulders I have been looking at rebarreling my AR10 from 308 to something with less recoil. And with the simplicity and todays choices of calibers, I can go from 308 to 6.5 Creedmoor, 6 Creedmoor or 243 with nothing more than a barrel change. Everything else from the bolt to magazines work for all of them.
As far as old versus new cartridges goes here is my take. If I had a rifle in an older caliber then I would just keep using it. Just like I do with my Enfield SMLE. But if I am buying new in a different caliber, then I am going to look at everything available and go with what suits my needs the best. And that is why my last centerfire AR build is a 6 ARC. I wanted something that is good for precision shooting and that I can still use ethically for deer hunting. And both the 303 and 6 ARC will kill a deer just the same. But I am not going to use the Enfield SMLE for a lengthy range session, my bad shoulders won't hold up to that. I can shoot the 6 ARC all day long without any issues.
Since I have bad shoulders I have been looking at rebarreling my AR10 from 308 to something with less recoil. And with the simplicity and todays choices of calibers, I can go from 308 to 6.5 Creedmoor, 6 Creedmoor or 243 with nothing more than a barrel change. Everything else from the bolt to magazines work for all of them.
mcb
Member
If you are going to compare 300 WM to 6.5 CM in a military setting then at least use the ammunition the military is using in your comparison.
For 300 WM the military is using the Mk 248 Mod 1 ammunition. This is a 220gr Sierra Match King (G1 BC: .629 >2100fps, .624 1700-2100fps, .608 <1700 fps) pushed at a specified 2850 fps from the M2010 per the military spec.
For 6.5 CM the military is using the Law Enforcement Hornady 6.5 CM TAP Precision. Using the available specs on Hornady's Law Enforcement & Military website that is a 147gr ELD-M bullet (G1: 697) pushed to 2655 fps.
300 WM has a modest velocity advantage but 6.5 CM had a modest drag advantage. This adds up to fairly similar trajectory with 300 WM being marginallly flatter.
At 500 yards its 42.8 vs 49.9
At 1000 yards its 360 vs 401
Given the skill of the men that are shooting these that is not a big deal. Consistence of the ammunition will play a bigger role than the flatness of the trajectory at these extreme ranges.
Also consider the platforms:
300 WM is being used in an M2010 (or PRS) it weighs in at 17.5 pounds (PRS a bit over 18) without suppressor, is a bolt action, scope 6.5-20x50 (5-25x56) and a 10rd mag.
The 6.5 Creedmoor is being used in the M110 (among others) that weighs in at just shy of 14 lbs, semi-auto, scope 3.5-18x44 and a 20rd magazine.
Both cartridges and rifles are going to excel at different rolls but I suspect (from having the opportunity to play with both rifles in a non-active military settings) the M110 (in 308 or 6.5 CM) is a significantly more versatile weapon.
*And I am not sure this comparison is as valid as it was given that the US military is currently in the process of replacing 300 Win Mag with 300 Norma Mag. The Remington M2010 and PRS both used 300 WM (PRS also could use 7.62x51 and 338 Lapua Mag). The replacement for these two sniper rifles is the new Barrett ASR (MRAD) and it using 7.62x51, 300 Norma Mag and 338 Norma Mag. So for the dedicated long range anti-personnel sniper rifle 300 NM is taking over that role from 300 WM. For the more designated marksman role 6.5 CM is being tested by special forces along side the proven 7.62x51 and no doubt the new hotness 6.8x51.
-rambling
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