Here is a Sig Cross bolt next to a Cooper Model 52 in 270 Win. Both three lug bolts. If anything the Cooper looks by eye more heavy duty. I would want more than appearance to decide if it was able to stand prolonged pressures.
Sig wins contract with the 277 fury
- Thread starter DJ Fergus
- Start date
Help Support Long Range Hunting Forum
tracybartlein
Active Member
- Joined
- Jul 16, 2008
- Messages
- 41
Just as a fyi to anyone following/reading this thread.
I've told the guys in the office here....that we will not chamber/install any barrel for a customer in this caliber.
I will not warranty any barrel from copper fouling, accuracy, safety etc....
Anyone installing one of our .270cal barrels and having they're gunsmith and or themselves chambering one of our blanks up in this caliber.... again at this time No warranties will be covered etc...
Could my feelings change on the above? Possibly but at this time no guarantees.
Last I heard was the 80k psi ammo will not be available to the general public. Doesn't mean some will not get out there.
Also I totally see someone tinkering and playing with this round and go... "I'll just load it up until I get to 3000+ fps with a 140gr bullet!" but they don't and won't have a clue as to the pressures they are dealing with and the safety margins in components can be compromised.
We've made a lot of ammunition test barrels in both accuracy and pressure and the data I've seen so far has me to be on the cautious side of things.
Later, Frank
Bartlein Barrels
Lenny Foffa
Well-Known Member
- Joined
- Mar 6, 2017
- Messages
- 1,667
Hi A, Thanks for quoting my post. I am not bashing or promoting the new .277 Fury. I see you have come to the determination that this new round poses no complications for use in current sporting rifles, as manufactured today. Thats excellent news. Thank You. As I sated, clearly I find this new round really interesting.
So, get the new .277 Fury brass, neck it down to the .264 caliber for the win
DavidA
Well-Known Member
That is a problem. Not knowing what pressure signs look like at 80,000 psi. The bolts would Handel it, but only using dimensional comparisons could be misleading depending on the difference in alloys used. But boltvsaftey sheets are probably set a 5.5 times failure.
But 80,000 psi load's would accelerate throat erosion crazy fast. Again it might require using a Speacial metal alloy insert or coating process for the first 2" of the bore. Otherwise your barrels would need to be changed as much as your underwear.
It can be done and done safely, but you need to do s lot of testing to figure out just what needs to be done. Then just like the hybrid case you develop a hybrid barrel manufacturing process .
If you do testing yourself , you are going to need a lot of equipment and know how. Like with a stress gauge on different parts of the rifle to see just what need to be done. So slapping a new barrel and hoping for the best may not be practical, or safe.
It's always desirable to be on the leading edge, just don't want to be on the bleeding edge
But 80,000 psi load's would accelerate throat erosion crazy fast. Again it might require using a Speacial metal alloy insert or coating process for the first 2" of the bore. Otherwise your barrels would need to be changed as much as your underwear.
It can be done and done safely, but you need to do s lot of testing to figure out just what needs to be done. Then just like the hybrid case you develop a hybrid barrel manufacturing process .
If you do testing yourself , you are going to need a lot of equipment and know how. Like with a stress gauge on different parts of the rifle to see just what need to be done. So slapping a new barrel and hoping for the best may not be practical, or safe.
It's always desirable to be on the leading edge, just don't want to be on the bleeding edge
lyle2231
Well-Known Member
DoD changed to the 5.56 so soldiers could load out 200 rounds combat load, .308 was too heavy (M14) So now DoD going to a heavy round , bigger (heavier) weapon.
Now consider M16 for jungle fighting and .308 for flat land combat (Europe). My guess is they are tooling up for Europe action.
Just my 2c……
So you're showing bolts, does that indicate this round will be for "special warfare" troops. Or a machine gun platform? Or ground troops be issued bolt guns? Makes me consider perhaps MA Deuce is being phased out.
Just saying…..
The brass 277 Fury case is a standard 60,000 psi area case, about the same as any brass case. Ya need the bi-metal Stainless steel 6.8X 51 mm military case to get to the 80,000 psi. Of course none of this is recommended by any manufacturer.
Interesting developments on about 5 weapons manufacturers working on this new military small arms demand.
Some are like "AI" developed "smart rifles" with fully integrated printed circuit electronic rails for attaching "special gear"...and capable of communicating with cell towers and "secure" government servers.
Totally different designs and concepts on the horizon, with respect to small arms.
The plastic /stainless head cases are interesting. Saint Marks went over 60 propellants to develop the perfect recipe. Many of the big name military contractors involved to get the final contract.
Smaller internal case capacity and 10% less powder equals much higher velocities?...
They rechambered a Remington 700 for the experiment, before going to the auto and full auto weapons, for the 80,000 psi test!
They met the Army requirements at a mere 65,000 psi with a bullpup design and an 18" barrel, and 3000 fps.
The plastic small volume plastic/ SS head cases take 20% of the heat out the firing process, converting it to velocity energy. There is no neck on the case it ends at the shoulder, and is loaded with standard military primers.
The author was allowed to shoot a 5 shot group that went into .230" at 100 yds with the military auto rifle to be submitted, velocity waa spot on S/D was double digit but not bad. The trigger pull was over 8 lbs! The other information about the rifle is classified...some rumors say the cases can take 100,000 psi. These do not look reloadable...how do ta resize a plastic case with no neck...glue in the bullet? The case has a thick plastic shoulder, it internally tapers down to the bullet, funneling the powder gas to the base of the bullet rather than the internal case shoulder and bullet base in normal case designs.
There are at least 4 big name military contractors working on new developments, science and engineering are being pushed to the limits to meet Army's new small arms requirements...with full electronics, integrated battle capable systems and communications available on some. Do a Google search with your rifle! Call home from the battlefield! Checks your vitals, knows the round count and its barrel temperature. A sniper rifle that will not fire when the reticle is off target, just pull the trigger and move the gun, it goes bang when you're on target at 1200 yds ..it hit, with a female reporter who never fired a rifle before ... A smart rifle ! Times are changing. Are programmed bullets next?
The bolt with the larger radius on the lugs with respect to the bolt body will take more pressure, thats the bolt on the left ...if they have equal heat treatment.
I believe they are producing a possible replace.ent for the M4 and a light machine gun to start with at least that is what I remember reading.
I am not an expert just have a bolt from each to compare. I haven't taken any measurements on them but I will.
lyle2231
Well-Known Member
If DoD is developing a replacement for the SAW I think that the bolt lugs will be ripped off, barrel extension chewed up @80k psi in no time.
I'm no mettalurgist just have practical experience.
The army has tested them in autos, and MGs the first 820,000 rds and you can purchase one of the same in semi auto from Sig for around $8000 complete with suppressor and a SBR tax stamp. A Great neighborhood watch weapon...There are videos of them...mag dumps down range at 80,000 psi...the government can afford it.
rscottb
Well-Known Member
Shooting a 152mm Beehive round out of a Sheridan (M551A1 TTS) removes most of the brush. Great little instant brush clearing charge. Kinda loud.
I wonder how many rounds the SAW gunner would lose from normal load, considering the weight difference.
