what do you know about 12.7x55

[blomqvistjs]

case specs and loaddata would be nice.
where can i find dies?

how do i trim down the case?
what powder and load?

this would be my dreamcaliber for subsonic hunting

 

[wookie76]

You can check out a drawing on municion.org (don't have linking privileges yet). Can't say whether or not it's correct, as it's not on the CIP website. Looks like the parent case is 338 Lapua brass cut down.
Looks like a niche product limited to Russian special forces.

 

[Bravo 4]

I use something similar, it's more of a 12.7x60. That would be a .300 Ultra Mag (7mm or .375) cut off at the shoulder. If you wanted to have your own reamer made its pretty simple, you could have it shortened a little if you wanted. Then just use .50 Alaskan dies. Here is a picture I've posted on here a while back, with 725 grain Lehigh subsonic fracturing bullet.

 

[HARPERC]

What type of firearm system did you put it in?

 

[Bravo 4]

A Savage long action.

 

[wookie76]

RUM donor brass makes way more sense, or WSM blown out full.

For an auto-loader, you might be able to cobble something together out of a donor Vepr 7.62x54r, but those are suddenly much to valuable to go hacking up for experiments. Maybe a Saiga .410? Not sure what it would offer over the 50 Beowulf anyways.

@bravo4, looks like you've had parallel thinking with the 500 MDM, from
b-mriflesandcartridges.com.

 

[Bravo 4]

The difference in the Beowulf & MDM and my rifle is theirs are true .50 calibers, mine is a .510 so I can shoot BMG projectiles. My original plan was to shoot the 750 grain Amax, it has an adversed BC of over 1.0. When you run the numbers (even subsonic) it will lose only 100 fps out to 600+ yards.
I also have a stash of BMG projectiles to "plink" with.

 

[Bravo 4]

750 Amax

 

[wookie76]

The difference in the Beowulf & MDM and my rifle is theirs are true .50 calibers, mine is a .510 so I can shoot BMG projectiles. My original plan was to shoot the 750 grain Amax, it has an adversed BC of over 1.0. When you run the numbers (even subsonic) it will lose only 100 fps out to 600+ yards.
I also have a stash of BMG projectiles to "plink" with.

Cool deal. Have you tried loading the BMG's backwards, that seemed to be the fad for a while.

 

[Bravo 4]

Yep, it works in my rifle. Allows me to load from the mag, negated to use of a filler, and hits noticeably harder.

 

[THEIS]

Hello,

I am playing in that region of the world right now. I will see if I can go visit the "Bureau" next week and put my hands on their ammunition and weapons for you, so I can give you the information from the horses mouth lol.

Will also get information from the guys on the wrong end of that system as I am with a Special group of Ukranians this week.