Testing, testing...

[warped]

I concur, it becomes a logistical exercise that may not be very pleasant.

[stanc]

While I laud the motivation for carrying out such testing, I must draw attention to the recent ARDEC calibre study which may make it unnecessary.

The Army is keeping very quiet about this, but according to the info I am picking up, they did a thorough job. 5.6, 6.2, 6.5, 7.0 and 7.8mm projectiles were tested, each in two bullet styles (Barnes TSX and a "GP" bullet similar in design to M855A1 EPR) ranging in weights from 61 for the 5.6mm to 165 for the 7.8mm.

The 6.5 and 7.0 performance was superior across the board...

By 6.5 and 7.0mm, do you mean .264" and .284", or .257" and .277" bullet diameters? It appears to me that it's the latter, which would mean that what we refer to as 6.5mm (as in 6.5 Grendel) wasn't even part of the test.

This seems to be corroborated by Gary Roberts, who wrote: "...the ARDEC caliber study that conclusively proves the superiority of .277" projectiles compared to smaller calibers..."

http://www.m4carbine.net/showpost.php?p=1017090&postcount=96

[Tony Williams]

By 6.5 and 7.0mm, do you mean .264" and .284", or .257" and .277" bullet diameters? It appears to me that it's the latter, which would mean that what we refer to as 6.5mm (as in 6.5 Grendel) wasn't even part of the test.

This seems to be corroborated by Gary Roberts, who wrote: "...the ARDEC caliber study that conclusively proves the superiority of .277" projectiles compared to smaller calibers..."

I mean .257 and .277 bore diameters, .264 and .284 bullet diameters.

I suspect that Gary Roberts was just following the military convention of giving calibres as bore diameters.

[stanc]

I suspect that Gary Roberts was just following the military convention of giving calibres as bore diameters.

Probably not. He's a long-time supporter of 6.8 SPC (.277" bullet).

[warped]

That was putting it mildly Stan....

[LR1955]

Probably not. He's a long-time supporter of 6.8 SPC (.277" bullet).

Stan:

I talked with Roberts at length numerous times over the phone and as I can recall, AA did not submit a Grendel or ammo for that series of tests. And yes, at that time -- three or four years ago I believe -- the 6.8 performed better in jel than the issued ammo. That should not have been a surprise as the 6.8 that was tested was designed for CQB and you won't find many small arms cartridges differing to any significant degree in ballistics to 300 meters.

I recall the heated debates with him on the last forum with the continual implications that he skewed the testing and results in favor of the 6.8. I do not think he even played a role in the test protocols or the final report.

LR55

[stanc]

I talked with Roberts at length numerous times over the phone and as I can recall, AA did not submit a Grendel or ammo for that series of tests. And yes, at that time -- three or four years ago I believe -- the 6.8 performed better in jel than the issued ammo.

Gene:

That's a different series of tests, which were done by an organization other than ARDEC. The ARDEC study currently being discussed was, as I understand, done within the last year or so, and apparently did not test cartridges like 6.8 SPC and 6.5 Grendel. According to what Tony posted previously, it was a comparison of different caliber bullets only.

If Tony's list is complete, then .224, .243, .264, .284 and .308 bullets were tested, with .257 and .277 omitted.

So the next question is, is Tony wrong about what bullets were evaluated, or is Gary mistaken about .277 being tested, let alone being the best performer?

Stan

[Tony Williams]

Gene:

That's a different series of tests, which were done by an organization other than ARDEC. The ARDEC study currently being discussed was, as I understand, done within the last year or so, and apparently did not test cartridges like 6.8 SPC and 6.5 Grendel. According to what Tony posted previously, it was a comparison of different caliber bullets only.

If Tony's list is complete, then .224, .243, .264, .284 and .308 bullets were tested, with .257 and .277 omitted.

So the next question is, is Tony wrong about what bullets were evaluated, or is Gary mistaken about .277 being tested, let alone being the best performer?

Stan

The notes I have are a bit ambiguous, so I'm doing some checking over the exact calibres used.

They certainly fired the bullets from something, and measured the results out to 300m, but exactly which cartridge cases were used I'm not sure.

[warped]

As I understood it, the .277 was omitted.

[Bill Alexander]

Time will probably sort everything out.

As I understand the ARDEC study and read its contents then some of the things being touted are not exactly as others would wish them to be. This said this is a closed study with a restriction on the disemination of data. It is a pitiful situation when those who are so placed to be (officially)appraised of the work cannot keep their mouths shut.

In the community as a whole such behaviour now created chasms in how data is procured and leaves both contractors and staff suspitious as to the motives of otherwise useful entities.

[stanc]

Okay, Gary Roberts posted the following on arfcom:

"As presented at a joint USG meeting this past March, the bullet diameters tested were described as: .224", .243", .257", .277", .308""

Converted from inch to metric measurement, those figures correspond to projectile diameters (not calibers!) of 5.7, 6.2, 6.5, 7.0 and 7.8mm, the sizes Tony said were tested.

Which means that it was .264" which was omitted from the test. The Army did about the same thing once before. When developing variations using the 7.62x51 case to create the "homologous" rounds, there was a .25-caliber version and a .27-caliber version, but no .26-caliber.

[LRRPF52]

If the government is involved, I just think DMV + D.C., with at least 25% of the funds for whatever it was unaccounted for on average, so I don't look for much validity in anything coming from that hybernaculum.

We'd be better off giving the money they're most likely wasting back to the States so units can put it to their ammo training budgets. I just learned that the Pentagon controls 95% of my State's National Guard budget. Nice...I guess that's why they're not called State Guards anymore...

This ARDEC testing wouldn't surprise me if it was just one big spendex, with no real results coming from it...like OICW from the 50's. We have bigger problems to fix than caliber, that's for sure.

LRRPF52

[warped]

That was the sound of money being flushed down the toilet.

In the end I think that was exactly the exercise, not doing anything but spending money was the important part.

[Tony Williams]

Okay, Gary Roberts posted the following on arfcom:

"As presented at a joint USG meeting this past March, the bullet diameters tested were described as: .224", .243", .257", .277", .308""

Converted from inch to metric measurement, those figures correspond to projectile diameters (not calibers!) of 5.7, 6.2, 6.5, 7.0 and 7.8mm, the sizes Tony said were tested.

Which means that it was .264" which was omitted from the test. The Army did about the same thing once before. When developing variations using the 7.62x51 case to create the "homologous" rounds, there was a .25-caliber version and a .27-caliber version, but no .26-caliber.

Yes, that is correct - my initial assumption that the usual military convention of quoting bore diameters applied was wrong. Neither the classic 6.5mm (.264 bullet diam) nor the 7mm (.284 bullet) were tested.

[warped]

If ever a new cartridge gets accepted for a NEW weapon, not just one for the existing platforms, I would bet even money it will look an awful lot like the 6.5x47Lapua.

If they only wanted to fit the AR/M series magazines it would be the Grendel