5.56mm trials - rumour

[woodchopper]

Ok I've been digging into old files from back when the US adopted the 5.56x45mm.

Now I'm trying to sort out a rumour that at the time the Army was adopting the M-16 there was a request that the 5.56mm bullet be replaced with a .25Cal bullet on the same x45mm cartridge but nothing came of this request.

Its interesting to note that in some of the later NATO trials the British were playing around with 6.25mm bullets, and the US did some development of a 6mm SAW cartridge.

 

[green]

There was some experimental 25 ctgs made on the shortened 25 Remington ctg in the 1950s as part of project Salvo but I have not saw any info on 25 built on the 5.56 case.

 

[saskcop]

A NATO 6.5 mm round would have solved a world of issues and would have worked in a GPMG too.

 

[woodchopper]

There was some experimental 25 ctgs made on the shortened 25 Remington ctg in the 1950s as part of project Salvo but I have not saw any info on 25 built on the 5.56 case.

I'll dig into that.

Oh and a 6.25x45mm would of been a hell of a round. 100grn easy, oh well back to digging.

 

[mmattockx]

A NATO 6.5 mm round would have solved a world of issues and would have worked in a GPMG too.

6.5x45 or something with greater case capacity?


Mark

 

[Colt .45]

The brits were messing around with a .280 ctg before nato adopted the 5.56. I guess they were just too far ahead of their time at that point.

 

[fenceline]

Where would the current 300 Blackout and Whisper fall into line with this kind of round testing? What was old is new again?

 

[tootall]

Military Rifle & MG Cartridges, by Jean Huon shows a .25 Win on page 273
Also called .25 FA-T 110 or 6.35x48
Headstamped either WCC or FA, dated 58 or 59

 

[lawn gnome]

I did some digging in the AR bible. The Black Rifle by Blake Stevens and Edward Ezell.

Just after the engineering report fiasco whereby the AR15 was discredited came to light, the OCO, Office Chief of Ordinance, Dr Carten announced that the AR15 should be rebuilt around a 6.35mm or .25 caliber cartridge.
Partly suggesting that it was a solution to the problem of an issue over water in bore problem.
Increase of bore size to .258 inch overall. Projectiles were developed by Olin Winchester/Western as part of the project Salvo.

Sadly, Dr Carten was the one who attempted to sewer the AR15 project engineering results in order to preserve the recently adopted M14 project.
In reality, the 6.35mm was simply an attempt to divert funds and time away from the AR15 as a whole.
The 6.35mm project went on for about two years and was claimed as an evolutionary dead end.

Hope that helps.
I love Collector Grade publishing.

 

[woodchopper]

thanks that looks about right.

Too bad it was never followed up on.

 

[Gunnerlove]

Where would the current 300 Blackout and Whisper fall into line with this kind of round testing? What was old is new again?

Poorly as they have the ballistics of a water fountain.

Just my opinion.

 

[scott585]

The brits were messing around with a .280 ctg before nato adopted the 5.56. I guess they were just too far ahead of their time at that point.

with the old powders, .280 british was a larger case but almost identical to 6.8 SPC ballistically

 

[woodchopper]

The british adopted the 280 enfield for several years. 7x43mm same case head as 7.62x51. But churchill canned it in favor of a common nato round.

 

[TonyE]

Not really, although we formally adopted the "Cartridge S.A. 7mm Mark 1z" (the service nomenclature for the .280/30 round) it never actually entered service and no weapons other than the original test series were made. Whem the Conservatives won the General Election later that year Churchill rescinded the adoption, so it was only theoretically adopted for a few months.

Regards
TonyE

 

[ATOM]

The post-WW2 period was dominated in the west by the USA and after the confusion of WW2, everybody wanted t0 standardize as much as possible. Conventional wisdom at high levels demanded a common NATO round, but the Yanks insisted that it had to be a .30 and capable of being used in semi and full-auto rifles, LMGs and GPMGs out to a fair range. They had the clout and everybody went along, except the French. The Yank then ran into two problems. The first was that the M14 was not particularly well suited for jungle warfare and they were just getting into Indochina. The second was that full-auto fire from the 7.62mm M14 was brutally inaccurate and a waste of ammo; the heavy-barrel version, the M15,was a waste of good steel and was soon dropped.

The problem was compounded by an extensive study of battlefield reports which concluded that infantry rifles with 800m range was pointless as most engagements were at 300m or less and many were below 100m. They also concluded that multiple rounds in the air were more likely to cause enemy casualties than deliberate aimed fire. This was another blow to the M14/7.62 combination as the M14 was very difficult to control in auto fire and the second was the sheer weight of ammo consumed.

There were a number of projects started, some competing, to solve the issue. There were any number of cartridges and rifles proposed and trialed, including duplex and triplex rounds and bullets ranging from .22 to .25 to .27, as well as some firing sabotted finned flechettes. In the end, they decided to go for what is now the NATO 5.56mm round as the best compromise between hit probability, weight and so forth. Not a perfect solution, but one that worked as well as any compromise.