Sig wins contract with the 277 fury

[44-40]

I am confused. Are you talking about running brass cases up to 80K PSI, or modifying 277 Fury cases to shoot in a 6.5 CM rifle?
A picture of your experimental cases would be great.

Nope, not running brass cases in the 6.5 Creedmoor. I am running reformed 6.8X51 bi-metal military cases as the head stamp on the Stainless-steel head is 6.8X51 SIG. The 277 Furry has brass commerical cases at 60,000 psi or can also use bi-metal military 6.8X51mm rated at 80,000 psi. This is for my experimental purposes only. Fireformed a bunch of 6.5 Creedmoor with 140 gr RDF at over 3100 fps yesterday with a more readily available powder. I do not post pictures, and no load data ...none of this is recommended by the manufacturer, and would void warranties.

 

[44-40]

American troops in Viet Nam had shotguns with flechettes. I remember taking several of the shells apart, and was surprised at the number of little darts they held. OTOH, I talked to a Marine who had exchanged several shots at short range with the enemy, and said the flechettes didn't appear to have any effect on the enemy troop. He was confident his aim was good, although he admitted the other guy was shooting back at him and that might have affected his ability to get off good clean shots.

A few years back flechette shot shells were available at local gun shows ...I believe a company called Hi Tech Ammo used to have them in stock for anyone interested enough to check it out.

 

[akmtnhnt]

Nope, not running brass cases in the 6.5 Creedmoor. I am running reformed 6.8X51 bi-metal military cases as the head stamp on the Stainless-steel head is 6.8X51 SIG. The 277 Furry has brass commerical cases at 60,000 psi or can also use bi-metal military 6.8X51mm rated at 80,000 psi. This is for my experimental purposes only. Fireformed a bunch of 6.5 Creedmoor with 140 gr RDF at over 3100 fps yesterday with a more readily available powder. I do not post pictures, and no load data ...none of this is recommended by the manufacturer, and would void warranties.

Seems like a whole lot more work to turn 6.8x51 into 6.5cm rather than 260 rem.

 

[akmtnhnt]

The military is looking for something that will penetrate the Chinese vests.

The Tech of a steel screw-on case head is an old idea from the late '60s. There are some issues that will crop up later on down the road such as metal fatigue on bolts and lug abutments. Short barrel life will be a given, but you can bet that a different metal will be used in the barrels, Bartline has one such new metal that extends barrel life. Bullet coatings may be part of a new way to extend barrel life, reducing the engraving pressures.

Another issue that is bound to crop up is the relative strength of various actions, get ready for a shock.

There is also new technology on plastic cases to be used in std military ammo, but I have not heard anything about it for a while. The plastic is supposed to give a more uniform case wall thickness and a more consistent grip on the bullet.

There's not a bolt action currently in production that can't handle this round from the action's perspective. If it couldn't, it wouldn't handle anything in a magnum bolt face.

Here's why that's true and how to calculate it. https://riflebarrels.com/a-look-at-bolt-lug-strength/

 

[44-40]

Seems like a whole lot more work to turn 6.8x51 into 6.5cm rather than 260 rem.

It's probably close to the same effort, but I already own a 2 6.5 Creedmoors, and all the reloading stuff for that caliber. The 6.8 X51 is a better case design than the 6.5 Creedmoor and especially the 260 Remington. It would be better to make a chamber reamer 6.5 X 6.8X51 cased 6.5 mm. And that's what I'd do if I were building a rifle around the 6.8X51 case...it holds more powder than either of the other cases, and is of excellent design. Plus capable of high pressure loads. My Creedmoor fireforming loads were 140 RDF yesterday with a not the best available powder hitting 3156 fps. The unaltered 6 8X51 case and a properly throated barrel with the same dimensions except the neck 264 instead of 277 would be a little faster. The 6.8X 51 is excellent just as it is if proper high BC and 7.5 twist barrels were available, along with high pressure actions and barrel steels to handle the throat erosion. I am checking all that as I fully test this development to see if it fits my needs. It has promise, accuracy and low single S/D for long range with the 150 SMK .713 BC at 3000 fps ran it to 3050 the impact moved up on the target, but it groups at a velocity plateau of around 3010 fps area, same impact area in .3 to .4 grain of powder. But the powder is hard to get and the 8 lb keg is down about 4 lbs. So I have to use slightly lesser available substitutes for now, but that take alot of time to work up, but I have tons of data from brass cases. Tested the brass cases standard load for the 150 SMK at barley 2600 fps with H4350 shot a slightly larger .537" 5 shot group than the 6.8X51 high pressure case load with a different powder at 3000 fps into .421" 5 shot group and it had a lower S/D in this brief test. That was their 3rd firing. So it all has promise. There are possible downsides plus manufacturers support. Or if the military gets fully on this platform. Things could change drastically. It's all up in the air, and I'm just testing. Not recommended by any manufacturer.

 

[akmtnhnt]

It's probably close to the same effort, but I already own a 2 6.5 Creedmoors, and all the reloading stuff for that caliber. The 6.8 X51 is a better case design than the 6.5 Creedmoor and especially the 260 Remington. It would be better to make a chamber reamer 6.5 X 6.8X51 cased 6.5 mm. And that's what I'd do if I were building a rifle around the 6.8X51 case...it holds more powder than either of the other cases, and is of excellent design. Plus capable of high pressure loads. My Creedmoor fireforming loads were 140 RDF yesterday with a not the best available powder hitting 3156 fps. The unaltered 6 8X51 case and a properly throated barrel with the same dimensions except the neck 264 instead of 277 would be a little faster. The 6.8X 51 is excellent just as it is if proper high BC and 7.5 twist barrels were available, along with high pressure actions and barrel steels to handle the throat erosion. I am checking all that as I fully test this development to see if it fits my needs. It has promise, accuracy and low single S/D for long range with the 150 SMK .713 BC at 3000 fps ran it to 3050 the impact moved up on the target, but it groups at a velocity plateau of around 3010 fps area, same impact area in .3 to .4 grain of powder. But the powder is hard to get and the 8 lb keg is down about 4 lbs. So I have to use slightly lesser available substitutes for now, but that take alot of time to work up, but I have tons of data from brass cases. Tested the brass cases standard load for the 150 SMK at barley 2600 fps with H4350 shot a slightly larger .537" 5 shot group than the 6.8X51 high pressure case load with a different powder at 3000 fps into .421" 5 shot group and it had a lower S/D in this brief test. That was their 3rd firing. So it all has promise. There are possible downsides plus manufacturers support. Or if the military gets fully on this platform. Things could change drastically. It's all up in the air, and I'm just testing. Not recommended by any manufacturer.

H4350 isn't what I'd use if I was seating a long bullet deep into a small case. Double base powders are more or less required if you want much velocity, even for brass.
To actually get up to 80kpsi and also have high velocity with a long high BC bullet in the SAAMI COAL, you pretty much have to be using one of the double base spherical powders.

 

[44-40]

H4350 isn't what I'd use if I was seating a long bullet deep into a small case. Double base powders are more or less required if you want much velocity, even for brass.
To actually get up to 80kpsi and also have high velocity with a long high BC bullet in the SAAMI COAL, you pretty much have to be using one of the double base spherical powders.

I said I use a different powder for the high pressure bi- metal cased loads when you re-read the post...I was just comparing standard load used to the high velocity loads for an accuracy comparison...those brass cased loads were pretty accurate not for highest attainable velocity even in standard brass cases...just accurate ...so just an accuracy comparison, because I hadn't shot this rifle in awhile. Your other assumptions are also incorrect.

 

[Knight]

Sig this and Sig that, I wouldn't get to concerned, it will probably be recalled like all their products..

 

[Moondoggie]

Sig claims it to outperform the 6.5 creedmoor at 1000 yards.

 

[akmtnhnt]

I said I use a different powder for the high pressure bi- metal cased loads when you re-read the post...I was just comparing standard load used to the high velocity loads for an accuracy comparison...those brass cased loads were pretty accurate not for highest attainable velocity even in standard brass cases...just accurate ...so just an accuracy comparison, because I hadn't shot this rifle in awhile. Your other assumptions are also incorrect.

You can absolutely get to 80kpsi with all kinds of powder, but not many of them are going to give the velocity that's the whole idea behind the thing. Just getting to 80kpsi doesn't mean the bullets shoot the same speed.

 

[DavidA]

I'm thinking take a 6,8. X 51 bimetallic case. Run it through a 260 rem full length turn the necks and voila. 260 REM on steroids. Load it to 80,000 psi and put some zhornady 147 , match or some Sierra 150 SMK's . That would be s screamer, you would need a Speacial coating for your throat or it would not last many rounds

 

[akmtnhnt]

I'm thinking take a 6,8. X 51 bimetallic case. Run it through a 260 rem full length turn the necks and voila. 260 REM on steroids. Load it to 80,000 psi and put some zhornady 147 , match or some Sierra 150 SMK's . That would be s screamer, you would need a Speacial coating for your throat or it would not last many rounds

Is there something wrong with 277 bullets haha? Most places have the reamers these days. Unless you already have a 260 rem...

 

[billflangjr813]

Now I need two or three!

Yeah, I wouldn't think that barrel life would be one of it's selling points. I wonder what a box of the ammo is going to cost. It's going to be interesting to see where & how far it goes with the consumer. Sig claims it to outperform the 6.5 creedmoor at 1000 yards. That statement may be all that's needed for someone to buy one, especially if one of the big rifle manufacturers offers it in a $250 rifle.

Well I'm Knot a real gun guy. But what about the 6.5 PRC over the 6.5 Creedmoor ?

 

[ADLEE2]

I'm thinking take a 6,8. X 51 bimetallic case. Run it through a 260 rem full length turn the necks and voila. 260 REM on steroids. Load it to 80,000 psi and put some zhornady 147 , match or some Sierra 150 SMK's . That would be s screamer, you would need a Speacial coating for your throat or it would not last many rounds

Bartlein 400MODBB, at least.