Reloading for the new .277 Fury from Sig

[Leaf Litter]

It will be very similar to 7mm-08 vs 280rem. The more powder a case has, the less efficient it is. In 280rem with a 150gr bullet you can expect around 2950fps with 55gr of powder vs 2800 with 45gr of powder in a 7-08. So a 20% increase in powder for a 6% increase in velocity.

For the all brass case 277 fury at 62.3kpsi vs a 270win(at saami max 62.3kpsi) with a 140gr bullet it's a 17% increase in powder for a 6% increase in velocity.

Of course a 20% increase in powder won't yield 20% velocity increase, you have to take into mind that energy is a V² equation, so it makes perfect sense that it doesn't carry 20% more velocity, but it will likely carry close to 20% more energy. And the square root of 20% more velocity.

 

[Batsin]

Just a couple of comments. Military ammo budget numbers show that many more rounds of the lower-pressure practice ammo has been ordered than full-pressure. It is very likely that these weapons will mostly see the practice ammo until sent into battle. The full-power ammo would shoot well beyond the safety zone of most ranges. This will be an issue with some practice ammo as well, which is why reduced-range ammo will be used a lot. This should increase barrel life significantly.

I don't think that action strength for civilian rifles will be much of a problem. Max backthrust on a bolt (and lugs) is max-case-dia X max-chamber-pressure. If you run the numbers, the backthrust of the .277 Fury at 80k psi is significantly less than that of a WSM or RUM cartridge running at 65k psi. Maintaining enough steel thickness around the chamber and in the first few inches of barrel should not be a problem. This is pretty much a non-issue.

 

[pupdistress]

Getting a +p done so I can burn through all my unique powder

 

[31perersen]

has anybody shot the Sig high pressure ammo for a 277 fury yet?

 

[Eric_F]

has anybody shot the Sig high pressure ammo for a 277 fury yet?

I haven't because I don't have a 277 Fury barrel (and no real interest in one) but I have formed some 6.5 Creedmoor hybrid cases which should be interesting when I get around to trying them.

 

[31perersen]

it's been a while and there's a handful of barrel makers selling the 277 fury. I have seen the sig hybrid ammo chronographed at 3017 fps out of the 16" barrel and just over 3100 fps with the 20" barrel. It sounds like the accuracy isn't great though. One of the companies selling the barrels has said accuracy out of the normal brass at lower pressures has been very good and only losing around 75 fps over the hybrid brass at 80,000 psi. I've reloaded a handful of resized hybrid ammo to 308 out of the 16", much lower than 80,000 psi but not fantastic accuracy out of the 2 bullets I've tried so far. I have found the eldx bullets to be fairly finicky before so that may be part of the problem. I'm also using the stock barrel which wasn't real accurate with normal ammo either (3/4" 3 shot group was the best I saw). Anyone else reloading or shooting any of the 277 fury now that it's out?

 

[Maol]

Nope. Curious though. Been wondering how it would shake out vs the 6.8 Western. 277 fury 140 gr at 3000fps out of a 16" barrel, while not sure a 170 gr will fit in a AICS mag correctly. IMO the Western is the better long range cartridge, and the Fury maybe better if a AICS mag is more important than heavier & longer with a better BC. For me the jury is still out on a factory replacement for the 270 WSM.

 

[akmtnhnt]

it's been a while and there's a handful of barrel makers selling the 277 fury. I have seen the sig hybrid ammo chronographed at 3017 fps out of the 16" barrel and just over 3100 fps with the 20" barrel. It sounds like the accuracy isn't great though. One of the companies selling the barrels has said accuracy out of the normal brass at lower pressures has been very good and only losing around 75 fps over the hybrid brass at 80,000 psi. I've reloaded a handful of resized hybrid ammo to 308 out of the 16", much lower than 80,000 psi but not fantastic accuracy out of the 2 bullets I've tried so far. I have found the eldx bullets to be fairly finicky before so that may be part of the problem. I'm also using the stock barrel which wasn't real accurate with normal ammo either (3/4" 3 shot group was the best I saw). Anyone else reloading or shooting any of the 277 fury now that it's out?

They're not actually running the hybrid brass at 80k if they're only seeing a 75fps difference. It should be 200-250.

I've got a gun built and a load worked up for a 140gr in the brass case. Still working on the hybrid with 140s and 150s. I'll post when I get done with it. I won't be testing the EOL as I have a 2.950 mag in this one.

For the brass case I settled on 47.1gr RL17 with the 140gr BD-2 That's giving me 2775fps. I saw pressure signs at 47.9gr, and that was giving 2835fps, but my groups were touching at 100 with the 47.1gr charge. This is almost identical to what a 270win will do with the same length barrel and bullet weight.

This is all with a 18in barrel.

 

[31perersen]

They're not actually running the hybrid brass at 80k if they're only seeing a 75fps difference. It should be 200-250.

I've got a gun built and a load worked up for a 140gr in the brass case. Still working on the hybrid with 140s and 150s. I'll post when I get done with it. I won't be testing the EOL as I have a 2.950 mag in this one.

For the brass case I settled on 47.1gr RL17 with the 140gr BD-2 That's giving me 2775fps. I saw pressure signs at 47.9gr, and that was giving 2835fps, but my groups were touching at 100 with the 47.1gr charge. This is almost identical to what a 270win will do with the same length barrel and bullet weight.

This is all with a 18in barrel.

That's pretty good, especially for the all brass case. I was guessing the same thing about what pressure they're running in the hybrid case. I didn't do the testing myself, but 1 thing to remember when guessing the pressure is that the hybrid is pushing a 150 nosler accubond, while the non-hybrid bullets are 130 and 135 grain so they should be faster. Did you end up with a barrel from Straight Jacket?

 

[Doom2]

They're not actually running the hybrid brass at 80k if they're only seeing a 75fps difference. It should be 200-250.

I've got a gun built and a load worked up for a 140gr in the brass case. Still working on the hybrid with 140s and 150s. I'll post when I get done with it. I won't be testing the EOL as I have a 2.950 mag in this one.

For the brass case I settled on 47.1gr RL17 with the 140gr BD-2 That's giving me 2775fps. I saw pressure signs at 47.9gr, and that was giving 2835fps, but my groups were touching at 100 with the 47.1gr charge. This is almost identical to what a 270win will do with the same length barrel and bullet weight.

This is all with a 18in barrel.

That would be expected since the 7.62x51 was a 30-06 performance clone (w/150 gr) so the 270Win and 277 would be very similar.

 

[akmtnhnt]

That's pretty good, especially for the all brass case. I was guessing the same thing about what pressure they're running in the hybrid case. I didn't do the testing myself, but 1 thing to remember when guessing the pressure is that the hybrid is pushing a 150 nosler accubond, while the non-hybrid bullets are 130 and 135 grain so they should be faster. Did you end up with a barrel from Straight Jacket?

No, I'm running this on a 700 clone, not the cross.

 

[31perersen]

No, I'm running this on a 700 clone, not the cross.

Oh, I see. I thought you were running the 277 140 bd2. So you are doing the same thing I was and resizing the brass to 308? I was running the 178 eldx at 2600-2660 with the 308 cross on a 16" barrel. It was pretty good but I was getting right at 1.25-1.5" at 100 yards. I only ran 1 powder though, which probably isn't optimal for short barrel and pressure. I hunt alit anywhere between -20 and 100 degrees (antelope) so I stick with the temp insensitive powders. Typically the insensitive powders are all slower unfortunately.

 

[akmtnhnt]

Oh, I see. I thought you were running the 277 140 bd2. So you are doing the same thing I was and resizing the brass to 308? I was running the 178 eldx at 2600-2660 with the 308 cross on a 16" barrel. It was pretty good but I was getting right at 1.25-1.5" at 100 yards. I only ran 1 powder though, which probably isn't optimal for short barrel and pressure. I hunt alit anywhere between -20 and 100 degrees (antelope) so I stick with the temp insensitive powders. Typically the insensitive powders are all slower unfortunately.

It's a 277 fury chamber running the 277 140gr bd2.

 

[31perersen]

It's a 277 fury chamber running the 277 140gr bd2

Oh, I see. So I was asking which barrel you were using earlier, who did your chambering/barrel?