Maximum energy subsonic

[ctdonath]

Considering that subsonic ammo maxes out around 1000fps, any thoughts on how to efficiently maximize energy with that limit? .50BMG bullets are somewhere around 650 grains, and I don't know of anything practically heavier (larger caliber has legal issues). Thing is, the .50BMG case is way too big. Is there a combination of heavy bullet and small case that optimizes for about 1000fps?

 

[Novus Collectus]

.510 Whisper I think.
http://en.wikipedia.org/wiki/.510_Whisper

 

[rangerruck]

maybe a 45 bushmaster.

 

[atblis]

Simple

How about a 45-70 with some really heavy bullets? It's straight walled, so I think you can have the bullet take up as much of the case as you want. 550gr is the heaviest I can think of at the moment.
http://www.beartoothbullets.com/open_sight/archive_open_sight.htm/21

 

[Car Knocker]

Sharps .50-70 or .50-90.

 

[atblis]

Similar

That would work as well.

I suppose you could use 50BMG bullets in the Sharps?

 

[.38 Special]

.700 Nitro fires a 1000 grain bullet. Big case and goes more than 2000 FPS, though.

Cut the case in half, I sez.

That would be the easy part, anyway. The tough part would be figuring out why you'd want such a thing.

 

[Mark Whiteman]

There are some wildcats loading a 200gr+ bullet into the 7.62x39 case, for example. Speed is limited by the small case capacity. There is a book out of cartridge conversions and several on wildcats you should peruse.

 

[Colt46]

Somebody already pointed out the Whisper

I can only add that it is a whole family of cartridges that are based on small bore centerfire cases that work in short actions. .221 Fireball seems to be a favorite with many conversions. I love the concept of a Whisper cartridge just to fool around with. One day I'll probably get around to it.
My two favorites would be the .338 and the 6.5 mm flavors.

 

[Tony Williams]

Take your pick from HERE:

Two pics from the article:

Tony Williams: Military gun and ammunition website and discussion forum