Hollow Point
CGN Regular
- Location
- New Brunswick
Anyone know if / when this will be available in canada?
will we ever see the .277 Sig Fury?
- Thread starter Hollow Point
- Start date
Civilian ammo is just now starting to dribble out in the USA. Tim on Military Arms Channel just got his hands on some. I expect that demand will exceed availability for quite some time, meaning that we are unlikely to see much (if any) before the US market is satiated. I'd be prepared to wait for quite a while yet......
Is that the hybrid case mil-spec stuff or just the brass cased ammo?
Battlerifleelitist
CGN Regular
- Location
- Annapolis Valley, NS
Guh it's so many costs for a decent but not amazing improvement, isn't it?
New bore with basically no projectiles for reloading, big questions on case life, throat erosion
New bore with basically no projectiles for reloading, big questions on case life, throat erosion
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
Not a new bore size. Just .277 or .270 Winchester calibre. The idea of getting it as a civilian gun is not appealing at all to me. The cases are bimetal so the extreme pressure of 80 000 doesn't cause issues with the brass flowing. The case price will be prohibitive, and make shooting costs ridiculous. Designed to give good performance out of a short 16" barrel, but will have an extremely obnoxious muzzle report with that kind of pressure and short barrel. Ballistic performance can be duplicated with a regular size .270 and common brass that a fella trips all over at the range.
Or if a fella craves more performance, it's easy to do with a .270 Short Mag, or either some kind of steamy 6.5 or 7 magnum.
I also wonder about some of the hidden costs and problems that will come with a new design.
A quick google search found places stateside selling primed .277 bimetal brass for <$59 USD/100 cases so it's hardly cost prohibitive. Being able to get the same performance out of a 16" barrel that you would a 24"+ barrel without going to a magnum is pretty impressive. Personally, I'm less interested in the .277 and more interested in the brass and re-sizing it into cartridges that I already run (6.5 creed, .308) to supercharge the performance of existing short barrels that I already have.
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
That's pulled cases. What is case life projected to be? What is regular new price? The figures I saw before were very high, but probably wrong also.
What are you using to figure out pressure?
How do you know your rifles are up to handling 80 000 psi?
Battlerifleelitist
CGN Regular
- Location
- Annapolis Valley, NS
I don't mean to spread FUD, but 54k psi to 80k psi would mean a fairly drastic increase in bolt thrust.
Though I'm just a redneck and yes, brass is almost always the limiting factor for pressure, a near doubling may be too close for comfort for repeated use out of some modern two lug actions.
I will say the price you quoted, and the fact that it's .270 (oops! on my part) has piqued my curiousity. If it's good and decently long lasting, perhaps the era of magnum boltfaces and long actions is over? or maybe we'll just see new hypermagnums using larger case capacity with this newfound case strength.
I don't think anyone knows what case life will be, at present.
There's a long thread on LRH about guys working up loads in either the .277 hybrid cases as is or in that brass that's been necked down to something different (6.5 creed, .260AI). Admittedly working out pressure is a bit of a challenge. From what I've read, pretty much all you have to go on is bolt lift and the primers.
As to 80k psi, I can't say but there are a few guys that are running it in normal 2-lug actions so I imagine we shall see.
Per the LRH thread (and the guys there that have done the math on bolt thrust), it's no more than you get a traditional magnum cartridges.
It's definitely interesting to have the possibility of getting magnum performance out of current chamberings. For what it's worth, I'm pretty confident that quality actions could take the pressure. There's currently an ammo manufacturer stateside that is putting out ammo in some new wonder steel alloy (the manfs name escapes me currently) that allows for way higher than usual pressures but runs fine in regular ARs. So far I think only the .223 is available but it gets something like 2900fps with a 77gr .223 bullet out of an 18" barrel with a regular .223 chamber. I have a couple buddies that have been running it with great success and they've also been testing .308 and 6.5 creed prototype ammo.
I just want 6.5 PRC performance out of my 18" 6.5 Creed, haha. I'd presume barrel life would be the same (as the PRC) but you'd use significantly less powder as well as have the option of swapping back and forth between the hybrid cased ammo and regular ammo depending on your application.
Battlerifleelitist
CGN Regular
- Location
- Annapolis Valley, NS
OK I'm sold, this is our time's 45 Super I think
Normal mags, normal boltfaces etc
Nice
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
Most of the new high pressure SAAMI ratings are around 62 000 psi, with a few reaching 65 000. The .308 is 62 000. I think you might have found some old copper crusher method pressures? With a fairly straight case with little taper, the brass will grip the chamber walls pretty well. Most failures are what's known as hoop failures where the walls of the chamber give way. Still, 80 000 is quite an increase and bolt thrust is definitely nothing to be ignored. 29% more, is nothing to sneeze at, and I wouldn't be throwing that in the chamber without some thought and calculations.
Brass flowing is somewhere around 70 000 psi, which is quite a bit of pressure.
I'm pretty loathe to jump on these bandwagons, as all too many end up near obsolete, and cost/effort prohibitive to shoot.
All kinds of unknowns thus far. Powder volume to bore size is a good indicator of barrel life, but I'd like to know how much extra pressure will affect that. And having 2 pieces of dissimilar metal mechanically joined makes me wonder how many times you can reload a case; if that's even recommended and how you gauge when it's time to toss it. What happens when it fails, and how do you tell when it'll happen? An 80 000 psi massive case rupture just doesn't sound all that appealing.
I'm not certain, but at that pressure, magnum primers, or military primers with a thicker cup might be in order to keep primer flow around the firing pin and perforations from happening.
Muzzle blast is a consideration also, and using a much touted 16" barrel doesn't sound that fun either. The military will have suppressors, while our ears will be subjected to maybe another 5000 psi of sound pressure at the muzzle.
To put it simply, what real world advantage would I see, and at what cost? I'm not going to have a stubby barrel high velocity magnum, so doesn't matter what a short barrel does. And if I want a little more velocity, there is a number of big cases that will top the fury's velocity with regular brass. Finally why would I pick a .277? Maybe things changed the last couple years, but better (or at least more choices) of higher BC bullets are generally available on either side by going to a .264, or .284 bore.
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
Bolt thrust may or may not be a limiting factor, but keep in mind that a magnum action is designed for magnum bolt thrust. A .308 sized action is designed for commensurate bolt thrust.
Might be measuring how much your action can take observing the beginning of lug shear and backing off of that.
For what it's worth, there's no difference (other than the bolt face) between the receiver of a Remington 700 in .308 and one in 7SAUM, 6.5 PRC, etc. As in, you can get (and I have a few for R700s and ARC Nucleus) magnum bolts or bolt faces for lots of short action receivers.
A magnum action is not designed to accommodate more bolt thrust.
It’s designed/modified to accommodate the cartridge dimensions. 308 sized action doesn’t mean anything.
You can take a tikka t3 they’re all medium length actions with the same lug bearing surfaces from 222 to magnum whatever.
You can apply this to rem, win, savage…..some of the euro trash.
The lapua 338 designed guns might like the trgs/41/42, ai…..surgeon 1581 might have
The cz/Brno 602, Brevex, true Mauser magnum receivers all got designed to feed large and long cartridges.
You wouldn’t want to shoot that sig 277 through any of them, dumb
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
I'm not talking about cartridge length. There's a reason I don't have a new Tikka bolt in my collection.
I've had a miniature Mauser Hornet, a small 30 cal designed around a cartridge under 50 000 psi SAAMI, and a true magnum length action designed for a large case cartridge. I don't think it's a stretch to think that they're all designed around different bolt thrusts.
A .473" case head diameter action might be a little different than one that has a diameter of .585". Maybe there is, or maybe there isn't a difference between bolt lugs and action strength, but I'd really want to examine that before saying "the .277 has less bolt thrust than a magnum". Who cares? WHAT magnum? Does the magnum come in a rifle scaled for a .308 sized round?
What's dumb?
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
That's useful information, and that'd work fine if it'll take the higher bolt thrust of the bigger cases. What I'm saying is it might not be universal.
That being the case, I'd measure how much steel is around the chamber.
No such thing as a miniature Mauser action.
It is a stretch same reason the tenon size doesn’t change. Between a 308 action vs one chambered in a magnum cartridge.
Did Jr cox design this superior “magnum” action?
So an Anschutz 54 rimfire action was designed for the the bolt thrust of a 22 hornet or 222?
It is a stretch same reason the tenon size doesn’t change. Between a 308 action vs one chambered in a magnum cartridge.
Did Jr cox design this superior “magnum” action?
So an Anschutz 54 rimfire action was designed for the the bolt thrust of a 22 hornet or 222?
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
Mauser style, but I'm sure you know what I mean. The 54 presumably was not initially designed to handle a Hornet or .222, but there's a little difference when a factory engineer signs off on it being strong enough.
There's reams of information and debates on various action strengths. Not all created equal, and I'm not saying anything new about it. Guess it's ultimately up the end user to figure it out.
A 30-30 action will take the power of a hopped up 45-70, or .444 Marlin too, but I don't think too many fellas would load a 30-30 to .308 pressures even if they could get bimetal cases for them.
