3 ms·

5.56x45mm? Aka .223 Remington? 7.62x51mm? Aka .308 Winchester? Only two of the most common NATO standards.

by ethbro 7y ago

galkk 7y ago
This is incorrect. 5.56 != .223 Remington, same for 7.62 It's actually very dangerous to former in civilian guns, designed for latter.
- ethbro 7y ago
  Citation for 5.56 vs .223? Fact: The external case and bullet dimensions are functionally identical Fact: The chamber dimensions in respective rifles are close enough, +/- machining tolerances, that "very dangerous" is inaccurate fearmongering Fact: 5.56 max pressures exceed .223 pressures (to the tune of ~12.5%), but both are subject to the vagaries of exact loading So while it's not a good idea to fire 5.56 out of a cheap .223 rifle, it's not a death wish to do so out of a .223 engineered to accept the additional pressure. Curious where you're getting your information?
  - galkk 7y ago
    > Citation for 5.56 vs .223? > Curious where you're getting your information? The Sporting Arms and Ammunition Manufacturers' Institute https://saami.org/wp-content/uploads/2019/02/Unsafe-Arms-and-Ammunition-Combinations-Web-Site-and-Brochure-Master-Revised-2-18-2019.pdf https://saami.org/wp-content/uploads/2019/02/Unsafe-Arms-and... page 8: In Firearms Chambered For: 223 Remington Do Not Use These Cartridges: 5.56mm Military --- Also literally first entry in FAQ on SAAMI site: https://saami.org/faqs/#ammunition-firearm-chambered https://saami.org/faqs/#ammunition-firearm-chambered Can I use 5.56x45mm, 5.56 or 5.56 NATO ammunition in a firearm chambered for 223 Remington (223 Rem)? NO! It is not safe to shoot “5.56” “5.56 NATO” or “5.56x45mm” (“5.56”) ammunition in a firearm with barrel marked as being chambered in 223 Remington for a number of reasons. The main reason being that a barrel marked as chambered in 223 Remington will have a shorter throat into the rifling than a “5.56” barrel which may cause increased pressure when the “5.56” ammunition is fired in it. This can result in serious injury or death to the user and/or bystanders, as well as damage to the firearm. However, it is safe to use SAAMI-compliant 223 Remington ammunition in firearms with a barrel marked as chambered in “5.56.” If you are unclear about which ammunition is appropriate to safely use in your firearm, consult the firearm owner’s manual or contact the firearm manufacturer for further guidance. > So while it's not a good idea to fire 5.56 out of a cheap .223 rifle, it's not a death wish to do so out of a .223 engineered to accept the additional pressure. I can't find the manual online, but I'm sure that in my previous, not quite cheap, Tikka T3 Super Varmint manual it was written the same. It's only truly safe only when manufacturer says so (like it was with now discontinued Ruger Precision 223/5.56, if I recall correctly)
    - ethbro 7y ago
      5.56 isn't SAAMI-standardized in the first place, so they legally shouldn't say anything other than their wording there. Which you also see on many .223 rifles as you noted. But that's a legal perspective. From an engineering perspective, you can certainly shoot it. With risks somewhere between "It will behave exactly like .223" and "It will explosively disassemble your gun." But we're not talking about rocket science here. Machining dimensions / tolerances + chamber / barrel design + round pressure = risk All of which are variable enough in practice to make this a grey area.
      - galkk 7y ago
        Dude, this is insane. I sincerely hope that you don't apply this logic in public shooting ranges. You asked for citation, got it, and choose to ignore it. What you're saying is equivalent that you could go on a car that weighs 5.65 tons on a bridge that can carry only 5 tons, (given that for such bridges the both standard body and constructor explicitly says: "do not do that"). Is it possible? Of course. You even could reload your ammo with nitroglycerin and it still will fit into the rifle. Yes, there could be some protection built into construction, but this risk worth it?
        ethbro 7y ago
        Depends on the scenario. People know the facts and make informed choices. That's the differences between engineers and sheep.
kube-system 7y ago
Those are cartridges, not rifles.

5.56x45mm? Aka .223 Remington? 7.62x51mm? Aka .308 Winchester? Only two of the most common NATO standards.

by ethbro 7y ago

5.56x45mm? Aka .223 Remington? 7.62x51mm? Aka .308 Winchester? Only two of the most common NATO standards.

This is incorrect. 5.56 != .223 Remington, same for 7.62 It's actually very dangerous to former in civilian guns, designed for latter.

ethbro 7y ago
Citation for 5.56 vs .223? Fact: The external case and bullet dimensions are functionally identical Fact: The chamber dimensions in respective rifles are close enough, +/- machining tolerances, that "very dangerous" is inaccurate fearmongering Fact: 5.56 max pressures exceed .223 pressures (to the tune of ~12.5%), but both are subject to the vagaries of exact loading So while it's not a good idea to fire 5.56 out of a cheap .223 rifle, it's not a death wish to do so out of a .223 engineered to accept the additional pressure. Curious where you're getting your information?
- galkk 7y ago
  > Citation for 5.56 vs .223? > Curious where you're getting your information? The Sporting Arms and Ammunition Manufacturers' Institute https://saami.org/wp-content/uploads/2019/02/Unsafe-Arms-and-Ammunition-Combinations-Web-Site-and-Brochure-Master-Revised-2-18-2019.pdf https://saami.org/wp-content/uploads/2019/02/Unsafe-Arms-and... page 8: In Firearms Chambered For: 223 Remington Do Not Use These Cartridges: 5.56mm Military --- Also literally first entry in FAQ on SAAMI site: https://saami.org/faqs/#ammunition-firearm-chambered https://saami.org/faqs/#ammunition-firearm-chambered Can I use 5.56x45mm, 5.56 or 5.56 NATO ammunition in a firearm chambered for 223 Remington (223 Rem)? NO! It is not safe to shoot “5.56” “5.56 NATO” or “5.56x45mm” (“5.56”) ammunition in a firearm with barrel marked as being chambered in 223 Remington for a number of reasons. The main reason being that a barrel marked as chambered in 223 Remington will have a shorter throat into the rifling than a “5.56” barrel which may cause increased pressure when the “5.56” ammunition is fired in it. This can result in serious injury or death to the user and/or bystanders, as well as damage to the firearm. However, it is safe to use SAAMI-compliant 223 Remington ammunition in firearms with a barrel marked as chambered in “5.56.” If you are unclear about which ammunition is appropriate to safely use in your firearm, consult the firearm owner’s manual or contact the firearm manufacturer for further guidance. > So while it's not a good idea to fire 5.56 out of a cheap .223 rifle, it's not a death wish to do so out of a .223 engineered to accept the additional pressure. I can't find the manual online, but I'm sure that in my previous, not quite cheap, Tikka T3 Super Varmint manual it was written the same. It's only truly safe only when manufacturer says so (like it was with now discontinued Ruger Precision 223/5.56, if I recall correctly)
  - ethbro 7y ago
    5.56 isn't SAAMI-standardized in the first place, so they legally shouldn't say anything other than their wording there. Which you also see on many .223 rifles as you noted. But that's a legal perspective. From an engineering perspective, you can certainly shoot it. With risks somewhere between "It will behave exactly like .223" and "It will explosively disassemble your gun." But we're not talking about rocket science here. Machining dimensions / tolerances + chamber / barrel design + round pressure = risk All of which are variable enough in practice to make this a grey area.
    - galkk 7y ago
      Dude, this is insane. I sincerely hope that you don't apply this logic in public shooting ranges. You asked for citation, got it, and choose to ignore it. What you're saying is equivalent that you could go on a car that weighs 5.65 tons on a bridge that can carry only 5 tons, (given that for such bridges the both standard body and constructor explicitly says: "do not do that"). Is it possible? Of course. You even could reload your ammo with nitroglycerin and it still will fit into the rifle. Yes, there could be some protection built into construction, but this risk worth it?
      - ethbro 7y ago
        Depends on the scenario. People know the facts and make informed choices. That's the differences between engineers and sheep.

kube-system 7y ago

Those are cartridges, not rifles.