Reloading for the new .277 Fury from Sig

[Lou270]

The 80k is for this round specifically. No other rounds have this high of limit. Most are 60-65k max. Some old rounds are lower. Once approved by saami then manufacturers can design rifles and load ammo to saami specs. People often handload rounds 'hotter' than saami specs but manufacturer will not load ammo or put out load data that exceeds the limits.

 

[Lou270]

https://saami.org/wp-content/uploads/2020/11/277-Sig-Public-Introduction-Orig-2020-11-11.pdf

Lou

 

[C-130 Dude]

https://saami.org/wp-content/uploads/2020/11/277-Sig-Public-Introduction-Orig-2020-11-11.pdf

Lou

Thanks Lou270. I wanted to read this myself. Gotta know this stuff. Stay safe and have fun.

 

[C-130 Dude]

The 80k is for this round specifically. No other rounds have this high of limit. Most are 60-65k max. Some old rounds are lower. Once approved by saami then manufacturers can design rifles and load ammo to saami specs. People often handload rounds 'hotter' than saami specs but manufacturer will not load ammo or put out load data that exceeds the limits.

I know about pressure limits on other rounds but was not aware of this specific limitation on this round. Thanks

 

[ultimag43]

You can buy a rifle chambered for it and hunting ammo that appears to be well above what's possible with more standard pressures (uses the new case design for 150@3120@24").

I'm not familiar with exactly how saami works, what sets the limit on case pressure?

i can push a 162 eldx out of my 24 inch 280ai @3197 useing super performance
so 3120 for a 150 out out of a 24 inch 6.8 mm isnt all that impressive hell there are guys on here pushng
hammers at 3600 in a 270 winchester,,,,,,
we shal wait and see but i highly doubt saami is gonna let it run 80,000 psi
i'm willing to gamble it will be 65-68 thousand psi max
there is not a firearm produced today that is approved for anywwhere near 70,000psi
and you think sigs gonna get the go ahead? your kidding your self
SAAMI wont approve it
if saami doesnt approve it then manufactures cannot sell a rifle chambered for a non aproved caliber {look no further then the original p.o ackley desighed 280ai cartridges ]

until nosler got it approved gun manufactures couldnt offer a factory rifle in it because it was not saami approved ( it had tp be a wild cat ) then after saami approved it most manufactiers went with saami approved chamber & dies and stopped offering the original wildcat based dies
(look no further then redding dies for proof]

like it or not saami WILL HAVE final say on what pressure it gets approved at and im highly doubting it will be anywhere close to 80,000 psi, again wishful thinking on your part

 

[ultimag43]

SAAMI New V&P Test Barrel
Copyright © Sporting Arms and Ammunition Manufacturers' Institute, Inc. All rights reserved. No part of this publication may be
reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher.
NUMBER OF GROOVES:
WIDTH OF GROOVES:
TWIST RATE:
DIAMETER OF PISTON HOLE:
TRANSDUCER DIAMETER:
6
.108 + .002 (4.06 + 0.05)
7.00 (254.0) RH
Crusher pressures not established
.250 (6.35)
LAND AND GROOVE DIMENSIONS TO BE
WITHIN TOLERANCES THROUGHOUT
LENGTH OF BARREL.
UNLESS OTHERWISE NOTED,
ALL DIAMETERS +.0005 (0.013)
LENGTH TOLERANCE + .005 (0.13)


NOTE:
B = BASIC = REFERENCE DIMENSION = HEADSPACE DIMENSION
DIMENSIONS ARE TO INTERSECTIONS OF LINES (XX.XX) = MILLIMETERS
ALL CALCULATIONS APPLY AT MAXIMUM MATERIAL CONDITION (MMC)
277 SIG FURY V&P Test BarrelIssued: 09/23/2020 Revised: - -/- -/- - - -
DO NOT SCALE FROM DRAWING
TRANSDUCER LOCATION
1.451 - .010 (36.86 - 0.25)
.4634 (11.770)
1.250 (31.75) B.200 B
(5.08) 1.6261 (41.302)
1.6800 + .0005 (42.672 + 0.013)
.270 (6.86)
.277 (7.04)
Bore Dia.
Groove Dia.
.4727
(12.006)
BREECH
BOLT
FACE
.400 (10.16) B
.4714 (11.974)
2.025 (51.44)

.312 (7.92)
1.7562 (44.608) 
30° B
.4623 (11.742)

2.0420 (51.867)
*
*

*
.278 (7.06)
.312
(7.92)
.030 (0.76) R MAX
.125 + .030 R
(3.18 + 0.76)
45° B
2.075 (52.71)

*
.278 (7.06)
2.2278 (56.585) 
1° 30' B
CL
16.000 ± .010 (406.40 ± 0.25) 
WARNING:
Maximum Average Pressure levels greater than 65,000 psi may present increased risk of unsafe cartridge case or
firearm rupture and thus require cartridge case and/or firea
again looks like 65,000 psi directly from the link you provided thats a far cry from 80,000 psi your hopeing for
it will be approved for 65,000 not 80,000

 

[Aloeus]

i can push a 162 eldx out of my 24 inch 280ai @3197 useing super performance
so 3120 for a 150 out out of a 24 inch 6.8 mm isnt all that impressive hell there are guys on here pushng
hammers at 3600 in a 270 winchester,,,,,,
we shal wait and see but i highly doubt saami is gonna let it run 80,000 psi
i'm willing to gamble it will be 65-68 thousand psi max
there is not a firearm produced today that is approved for anywwhere near 70,000psi
and you think sigs gonna get the go ahead? your kidding your self
SAAMI wont approve it
if saami doesnt approve it then manufactures cannot sell a rifle chambered for a non aproved caliber {look no further then the original p.o ackley desighed 280ai cartridges ]

until nosler got it approved gun manufactures couldnt offer a factory rifle in it because it was not saami approved ( it had tp be a wild cat ) then after saami approved it most manufactiers went with saami approved chamber & dies and stopped offering the original wildcat based dies
(look no further then redding dies for proof]

like it or not saami WILL HAVE final say on what pressure it gets approved at and im highly doubting it will be anywhere close to 80,000 psi, again wishful thinking on your part

Hand loads are not a good indicator of pressure, you can be well over 65ksi without seeing pressure signs, and its generally in your interest to run the bullets faster (also thats a different caliber with a much larger case, not exactly 1 to 1, and the hammers are even less comparable). Show me the pressure tested book data that has a 150gr at 3100+ fps with 270 win. hodgdon shows a max of 2974, nosler a max of 2914. But even hand load data is different. That 3120 number is factory ammo, which is not likely to be loaded to saami max. Sig's own 270 win factory ammo, with a 140gr bullet, runs only at 2950. To compare to book data, nosler loads that 150gr I mentioned above at 2850. ALso keep in mind 6.8 fury is smaller than even 270 win. Its 6.8x51, and while I'm not sure how much capacity it has (not sure how much that base eats into it) its probably in the range of 58gr or less, where the 270 win is 67gr.

-snip-
again looks like 65,000 psi directly from the link you provided thats a far cry from 80,000 psi your hopeing for
it will be approved for 65,000 not 80,000

Right at the top it says: Maximum Average Pressure (MAP)* = 80,000 psi. There are warnings, yes, but the listed max pressure is 80ksi. Oh, and these are the official saami specs. Its already been accepted. Ultimately its not up to saami to decide max cartridge pressure. Its up to the gun manufacturers to be able to pass the saami proof tests.

there is not a firearm produced today that is approved for anywwhere near 70,000psi
and you think sigs gonna get the go ahead? your kidding your self
SAAMI wont approve it
if saami doesnt approve it then manufactures cannot sell a rifle chambered for a non aproved caliber {look no further then the original p.o ackley desighed 280ai cartridges ]

There are now 2 (MCX Spear and Cross, and at least 1, the spear, is actually out there. Somewhere, if you have money (theres one on GB for 18k from europtic). Again, its been accepted by Saami, and sig is now selling it.

 

[ARlife4me]

It's just a necked down to 27cal that goes back (not sure how far) to a wildcat (except for the 80k). QL has the cartridge on file as a 270-08 or 27-08 or 27/308.......something like that.

 

[2buffalo]

Not this

Not this.

 

[xsn10s]

 

[jpfrog]

If the components of the gun are designed to operate at higher pressure, why would SAMMI object? Is there a hard fast rule about this?

Sig themselves even stated that, although you could use the 80k pressure rounds in your rifle that you bought or built off a donor action, they don't recommend it. Basically, they indicated that civilian firearm manufacturers don't currently build civilian firearms to withstand these pressures constantly. They had to build the Mil version of this rifle with those pressures in mind so it could handle them.

The below excerpt is from a 2019 Guns America Digest article (https://www.gunsamerica.com/digest/277-sig-fury-demystified/)

"Can you have your gunsmith rechamber your favorite rifle in SIG Fury? Technically, yes. SIG has even tested several actions from other manufacturers. A Remington 700 can certainly handle it, but SIG doesn't recommend it, and for good reason.

That much pressure can be handled by existing actions, but they are not designed for it and it's going to wear on them. "We Built the Cross rifle like a tank," SIG says. Everything about this new action is engineered for longevity under the high pressure produced by this cartridge."

 

[cohunt]

Man - people get so bent out of shape over 80000 psi, I'm open to explore new things....also, Remember that sig said they have a proprietary process/coating for the barrels so that they would last longer than a standard gun barrel would at these pressures. I'd like to see that technology put to use on standard 65000 psi cartridge barrels if it's not too expensive

Are there dies to resize the high pressure hybrid cases yet?

I know that sig said they will make components available to the public in the future so cases and dies should become available at some point.

I was under the impression from things ive read in the past that the high pressure ammo will use a proprietary gun powder that may not be available to the public-- so even though you may be able to reload it, you might not be able to attain the same pressures and speeds of factory ammo.

 

[xsn10s]

Sig themselves even stated that, although you could use the 80k pressure rounds in your rifle that you bought or built off a donor action, they don't recommend it. Basically, they indicated that civilian firearm manufacturers don't currently build civilian firearms to withstand these pressures constantly. They had to build the Mil version of this rifle with those pressures in mind so it could handle them.

The below excerpt is from a 2019 Guns America Digest article (https://www.gunsamerica.com/digest/277-sig-fury-demystified/)

"Can you have your gunsmith rechamber your favorite rifle in SIG Fury? Technically, yes. SIG has even tested several actions from other manufacturers. A Remington 700 can certainly handle it, but SIG doesn't recommend it, and for good reason.

That much pressure can be handled by existing actions, but they are not designed for it and it's going to wear on them. "We Built the Cross rifle like a tank," SIG says. Everything about this new action is engineered for longevity under the high pressure produced by this cartridge."

I agree that shooting 80k psi in a firearm rated for 64k psi isn't probably something I would want to do with regularity. People can do it, I'll be watching from a distance. Load some at 65psi that's a different story. With a 24"26" barrel it might be close to 2950- 3000 fps anyways. Kinda like a 270 Win.

 

[xsn10s]

Who's going to be the cool kid on the block loading a 277 Fury with a 170 EOL in a mid length action?