quote:

Originally posted by boom stick:
Pretty much a short neck 6.8x57 Chinese Mauser from 1907 with a steel base.

quote:

Originally posted by vzerone:
I think it's a big mistake and a lot of bullshit. I don't see why the Army couldn't go a thou or more and make it a 7mm. I'm not sold on the case and weight savings isn't as much as when they went from 7.62x51 to the 5.56x45. Yes I realize and presume they are going from the 7.62x51 to this new round. They won't answer the barrel wear because they know it's going to wear it out faster and especially the throat, come on 80k psi hitting that throat even though the shoulder design supposedly would burn most the powder inside the case kind of like what the 6.5 Creedmore does. Or why didn't they just neck the 6.5 Creedmore up to 7mm?

quote:

Originally posted by craigster:

quote:

Originally posted by vzerone:
I think it's a big mistake and a lot of bullshit. I don't see why the Army couldn't go a thou or more and make it a 7mm. I'm not sold on the case and weight savings isn't as much as when they went from 7.62x51 to the 5.56x45. Yes I realize and presume they are going from the 7.62x51 to this new round. They won't answer the barrel wear because they know it's going to wear it out faster and especially the throat, come on 80k psi hitting that throat even though the shoulder design supposedly would burn most the powder inside the case kind of like what the 6.5 Creedmore does. Or why didn't they just neck the 6.5 Creedmore up to 7mm?

Well then, I think you should get in touch with the R&D engineers at SIG and share your insight with them. I'm sure they'd be all ears.

quote:

Originally posted by vzerone:

quote:

Originally posted by craigster:

quote:

Originally posted by vzerone:
I think it's a big mistake and a lot of bullshit. I don't see why the Army couldn't go a thou or more and make it a 7mm. I'm not sold on the case and weight savings isn't as much as when they went from 7.62x51 to the 5.56x45. Yes I realize and presume they are going from the 7.62x51 to this new round. They won't answer the barrel wear because they know it's going to wear it out faster and especially the throat, come on 80k psi hitting that throat even though the shoulder design supposedly would burn most the powder inside the case kind of like what the 6.5 Creedmore does. Or why didn't they just neck the 6.5 Creedmore up to 7mm?

Well then, I think you should get in touch with the R&D engineers at SIG and share your insight with them. I'm sure they'd be all ears.

I'm sure they would as there are many things wrong with this cartridge. Take for an example that case obturate to the chamber wall upon firing. This actually reduced the bolt thrust. Way back P.O. Ackley demonstrated this by taking the locking bolt out of a Model 94 Winchester 30-30. He took a loaded case and cleaned any oil,grease, or wax off it and did the same to the chamber. He fired it and it didn't blow the bolt open. With that said the steel part of the case on Sig's new cartridge is pretty tall. It's definitely more then 1/8 inch above the extractor groove cut. The only part of the case that is going to obturate upon firing is the brass portion. This is asking for a case separation especially where the two sections are joined. Add that it's running a 82K. How about primers? How are they able to take this pressure? They didn't answer the question on barrel wear because they know damn well it's going to be short. Low of throat erosion with that kind of pressure. They said they also tested it in another brand rifle mentioning the Remington 700 and said that it could take, but then they said they didn't think it would take it over time. I question the use in a full auto weapon. No doubt that it would have to be a closed bolt. We know full auto's a lot of things that bolt actions don't, like slam fire. Would you like to have a slam fire with an 82K round? I wouldn't. Also full auto's tend to develop excess headspace more then a bolt action, or say faster. This brings us back to the case separation because the steel part of the case, which is more then just the solid web, not obturating to the chamber.

These are some of the question that I have. I didn't mean to slight you. My opinion is it's closer in appearance to the 7.62x51 cartridge, maybe not in performance of comparing the 7.6x51 with the Chinese 6.8x57.

quote:

Originally posted by craigster:

quote:

Originally posted by vzerone:

quote:

Originally posted by craigster:

quote:

Originally posted by vzerone:
I think it's a big mistake and a lot of bullshit. I don't see why the Army couldn't go a thou or more and make it a 7mm. I'm not sold on the case and weight savings isn't as much as when they went from 7.62x51 to the 5.56x45. Yes I realize and presume they are going from the 7.62x51 to this new round. They won't answer the barrel wear because they know it's going to wear it out faster and especially the throat, come on 80k psi hitting that throat even though the shoulder design supposedly would burn most the powder inside the case kind of like what the 6.5 Creedmore does. Or why didn't they just neck the 6.5 Creedmore up to 7mm?

Well then, I think you should get in touch with the R&D engineers at SIG and share your insight with them. I'm sure they'd be all ears.

I'm sure they would as there are many things wrong with this cartridge. Take for an example that case obturate to the chamber wall upon firing. This actually reduced the bolt thrust. Way back P.O. Ackley demonstrated this by taking the locking bolt out of a Model 94 Winchester 30-30. He took a loaded case and cleaned any oil,grease, or wax off it and did the same to the chamber. He fired it and it didn't blow the bolt open. With that said the steel part of the case on Sig's new cartridge is pretty tall. It's definitely more then 1/8 inch above the extractor groove cut. The only part of the case that is going to obturate upon firing is the brass portion. This is asking for a case separation especially where the two sections are joined. Add that it's running a 82K. How about primers? How are they able to take this pressure? They didn't answer the question on barrel wear because they know damn well it's going to be short. Low of throat erosion with that kind of pressure. They said they also tested it in another brand rifle mentioning the Remington 700 and said that it could take, but then they said they didn't think it would take it over time. I question the use in a full auto weapon. No doubt that it would have to be a closed bolt. We know full auto's a lot of things that bolt actions don't, like slam fire. Would you like to have a slam fire with an 82K round? I wouldn't. Also full auto's tend to develop excess headspace more then a bolt action, or say faster. This brings us back to the case separation because the steel part of the case, which is more then just the solid web, not obturating to the chamber.

These are some of the question that I have. I didn't mean to slight you. My opinion is it's closer in appearance to the 7.62x51 cartridge, maybe not in performance of comparing the 7.6x51 with the Chinese 6.8x57.

Serious question,

Do you think the engineers/designers have not considered/thought of/studied all of the issues you have brought up ?

quote:

Originally posted by carpetman1:
Lots of unanswered questions. If Larry Gibson wasn't banned here I'm sure he could answer all of them.

quote:

Originally posted by jeffeosso:
the fascination with the .277 since the 1903 "mini machine gun"... ... i know, i know, "dah, the 7mm is a german thing".. i get it.. dang


why not just a steel case? the military doesn't reload, and this complex case offers no functional (shelf life?) over good ole steel cases, and the rossskies can even make them

pictures make it look like a 277x308 improved, at stupid pressures .. the last 100 fps is "Expensive" in terms of pressure .. and no real benefit ... sigh.. how about just the 308, or if you need a change, 708, and be done with it?

quote:

Originally posted by carpetman1:
Lots of unanswered questions. If Larry Gibson wasn't banned here I'm sure he could answer all of them.

quote:

Originally posted by carpetman1:
John C--I'm not a loyal follower of Larry Gibson, so I wouldn't hear his answers. Perhaps Vzerone could relay them?

quote:

Originally posted by vzerone:
I like your thinking Jeff. Better watch out Craigster will want both you and I go to talk to SIG!!! LOL

quote:

Originally posted by vzerone:

quote:

Originally posted by carpetman1:
John C--I'm not a loyal follower of Larry Gibson, so I wouldn't hear his answers. Perhaps Vzerone could relay them?

John C is on the CB forum, why can't he do it himself????

quote:

Originally posted by LHeym500:
Someone tell me the point of a special, expensive to tool up, hard to make, expensive to buy case running at 80kpsi to send a .277 caliber, 140 grain bullet at 3000 FPS.

When a 308, or 300 Savage based case will send the same bullet at 2800 FPS at 60-62kpsi.

That is what I want to know.

quote:

Originally posted by crbutler:
I’m not sure how well this is going to work out in the end.

It’s undoubtedly SIG’s answer to the military call for proposals. I don’t think that it will be financially useful for the military. It has to increase the costs of the case by a substantial amount.

I also doubt that another couple hundred feet per second make any meaningful changes to a machine gun.

I have no issues with the army trying to see what is possible; but for SIG to commit whole hog to a proposal seems financially silly on their part.

I’ve heard of 2 piece cases before. It may well do what they say it will, but will it be affordable and is it worth the price?

Remember the HK M8 boondoggle. That’s dead, and good riddance.

quote:

Originally posted by LHeym500:

quote:

Originally posted by crbutler:
I’m not sure how well this is going to work out in the end.

It’s undoubtedly SIG’s answer to the military call for proposals. I don’t think that it will be financially useful for the military. It has to increase the costs of the case by a substantial amount.

I also doubt that another couple hundred feet per second make any meaningful changes to a machine gun.

I have no issues with the army trying to see what is possible; but for SIG to commit whole hog to a proposal seems financially silly on their part.

I’ve heard of 2 piece cases before. It may well do what they say it will, but will it be affordable and is it worth the price?

Remember the HK M8 boondoggle. That’s dead, and good riddance.

Never having worked for the Feds or Big Military in any capacity, but from my observations and experience with State contracts, big gov only cares about funds when it wants to. It appears the Military is hell bent on spending upteen billion dollars to defend this acquisition. Much like they did until the 6.5 Creedmore finally , statically beat the 260 Remington during SOCOM acquisition.

The other round is that polymer cased ammo. It to uses a steel base. I think that company is called True Velocity.

No one has answered my question.

New question, how does a grasses round with steel rim cap reduce weight by 20 percent?

quote:

Originally posted by LHeym500:
New question, how does a grasses round with steel rim cap reduce weight by 20 percent?

quote:

Originally posted by jeffeosso:

quote:

Originally posted by LHeym500:
New question, how does a grasses round with steel rim cap reduce weight by 20 percent?

ah, yes.. while i have no clue into their rational, let's look at the maths?

if one says that the 308 uses a 168gr bullet as it's "big accurate bullet" and the fury uses a 140, ..

well, let's back into this -
assuming the 308 case weighs 85 + 40gr powder, +165gr bullet, +5 gr primer
295gr

now the plaque says "~20%" which means ABOUT 20% -- it's not 20+%, or it would say that, so 18.5% or more -- what do we need to be at 18.5%?
54.6gr less

20%?
59gr

so, we instantly get 25gr better with just the bullet swap to 140gr , 270

that leaves 30gr to be found "somewhere"

i could see 5 gr in superpowder

leaving 25gr to be found in the case.. but weight -- 25/85gr is a HUGE percentage weight loss, nearly a THIRD if the case weight...


of course if they started with a 180gr 308, they would only need 10%..



bottomline
if a 308, 165gr weighs 295gr, then a 277x08 with 140 would weight 285 .. assuming some voodoo with powder and lightweight case gets you another 40gr (wow)...but costs billions...

or load a 308 with 130gr ttsx, (yes, i know, no expanding bullets in military guns - make it pointy solid) BAM! there is MORE THAN HALF the weight saving (11.86%, nearly 12) just by changing the bullet... AND it would use less powder AND would hit 3k easy

that bullet has a higher BC
better weight retention
FAR superior accuracy
ZERO platform changes (for stuff already using 7.62)
it just results in another load for the 7.62 nato .. that doesn't have the pitfalls of changing the 223 bullet weights --

there's no super pressure loads

and if you used a ultra thin ss case, which is EASY and well -known manufacturing, the cases are lighter, there's no rust or lacquer to worry about

i expect that an apples to apples comparison, the 308 could win, if there were an impartial panel and very clever loaders .....

oh, and don't get me started that the "improved" part of the case could be easily matched with the 308 .. and still have the ability to fire existing nato cases in the chamber with little reduction is accuracy and precision - we've "all" fired regular cases in AI chambers, and are usually impressed that
there is little change in group size


yeah yeah, this was all mental masturbation on my end

Happy Christmas to you and yours!

quote:

Originally posted by LHeym500:
Looking at the model provided the steel cap goes over the brass rim ( damn autocorrect changed it to grasses). Adding steel would have to add weight.

Sig may sell them at a loss, but think how much was spent by the Government to shoot and test, reject, rewrite, refute Glock, etc.

That is what I am concerned about. The Governments cost at coming up with and testing the proposed design. Then think about the millions of rounds in warehouse that is going to half to be replaced. The Sig pistol can still use existing 9mm ammo. The utter paralysis by analysts, wasteful numbers crunching that went into the 7mm/08 v. 260 Rem, v 6.5 Creedmore by SOCOM to declare the 6.5 Creedmore a chin hair better. They literally kept shooting until the Creedmore gained a statical advantage.

This is going to require the purchase of all new ammo stores by Uncle Sam.

I thought there was a rule against awarding a contract for a round limited single source manufacturing.

I been shooting .277 caliber 140 grain bullets at 2950 FPS for 3 years. All be it, in a 2.5 inch case. That is a joke.

quote:

Originally posted by jeffeosso:
*270 -- math is hard ... dang it
165-140 is 25, not the TEN i did first

quote:

Originally posted by ALF:
With all of this pontification has anyone actually bothered to find out what the military's requirements are for the next cartridge ?

With all of this I would put money on it that somewhere in that requirement lies a personal armour defeating capability ?..... then something that stretches the effective range of deployment ( beyond the current 300 to 400 m of the 5.56 ) and then last but not least the smallest package capable of achieving the above...

quote:

Originally posted by ALF:
With all of this pontification has anyone actually bothered to find out what the military's requirements are for the next cartridge ?

With all of this I would put money on it that somewhere in that requirement lies a personal armour defeating capability ?..... then something that stretches the effective range of deployment ( beyond the current 300 to 400 m of the 5.56 ) and then last but not least the smallest package capable of achieving the above...

quote:

Originally posted by ALF:
With all of this pontification has anyone actually bothered to find out what the military's requirements are for the next cartridge ?

With all of this I would put money on it that somewhere in that requirement lies a personal armour defeating capability ?..... then something that stretches the effective range of deployment ( beyond the current 300 to 400 m of the 5.56 ) and then last but not least the smallest package capable of achieving the above...