Sunday, February 16, 2014

Ammo Debate

That is near and dear to my heart.

What if we went to .276 Pederson or the equivalent back in the 30s?  What if we did it now with something like the 6.8 Remington?  Replace both 5.56 and 7.62 with something better.  One Round to Rule Them.

Well THAT guy has the ballistics and reload chops to explore that idea better than I ever could beyond a slight bit of history I can call up.

Short answer: with the trade offs that you have to do, there is no big gain, or gain enough, to over come the hassle of the switch or really justify the switch.  Only in fantasy land can you make something as compact and light as the 5.56 be as effective as the 7.62.  Wouldn't it be nice, tho, if the laws of physics could be suspended?  But if wishes were horses, beggars would ride.  You want egg in your beer, too?


Angus McThag said...

If we'd gone with .276 Pederson back when we'd likely have been amenable to .280 British in the early '50's.

Whether we'd have made a new Garand in .280 Brit to replace the .276 M1 Garand is a matter of debate. And the FAL would still have been a contender because FN did chamber some of the early guns in .280.

Old NFO said...

Interesting question... :-)

jon spencer said...

Even if one could find a replacement cartridge, there is the multi-multibillion dollar cost of changing over.

Angus McThag said...

Historically we've changed round when we changed rifle.

And we really only change rifles when something stunning happens.

If 6.8 was developed in 195x and was the round the AR15 has had for the past 50 years, there'd be a debate about changing over to that upstart .222 Remington wildcat round...

Bradley said...

The 300black, 6.5 and 6.8 all have ~7.62 power at the ranges they are meant to be shot(sub 500m), and all will work in the normal AR lower.

Geodkyt said...

Sadly, the reality is somewhat different than the myth.

We could have bypassed the R&D costs almost entirely by adopting the 6.5mm Carcano with a spitzer boat tail bullet, and achieved performance comparable to the .276 Pedersen.

Keep in mind that BEFORE the turn of the century, we had the 6mm Lee in military service, with rifles and machineguns. However, the 6mm Lee suffered from the same fault as the .276 Enfield -- extremely short barrel life (for a service rifle), due to them pushing that bullet hard, hot, and fast, in an attempt to maintain the desired downrange performance (US military specs from the immediate post-Civil War period forward to and including the 7.62x51mm NATO harkened back to the same ideal - "Must kill or disable a horse at 1000 yards." (This was a decent requirement, in going back to an era where horses and direct fire artillery moved by horses were critical -- the 7.62x51mm NATO got the requirement grandfathered in when the design team was directed to maintain similar performance to the .30-06.)

Most major nations maintained roughly similar performance requirements thorugh the era of "full-power" bolt action rifles, with the 6.5mm crew (Italy, Japan, etc.) being outliers.

The Pedersen also had other flaws that made it a rather less-than-ideal cartridge for military service, necessitated by the action of the rifle it was built for.

Geodkyt said...

Don't forget the 6mm SAW round the Army played with in the 1970s, either. 105gr @ a skosh over 2500fps, for almost 1500ft-lbs. And that's without exotic bullet designs -- strictly low production cost military FMJ, no expensive coatings or match grade tolerances.

Sound familiar? :-)