.223 remington versus 5.56 x 45 mm NATO - is it safe to interchange???
- Thread starter Boltgun
- Start date
I've read on here people claiming that even though the h&k sl8 is stamped .223 on the barrel, something on the internals says it's 5.56. And they even claimed h&k "told them" that it's safe to fire 5.56 out of it
My communications with h&k were different, they said to me in an email:
"The SL8 clearly states .223 and is the manufacturer specs."
Glad I could set the record straight on this
My communications with h&k were different, they said to me in an email:
"The SL8 clearly states .223 and is the manufacturer specs."
Glad I could set the record straight on this
The Europeans use CIP standards for pressure testing. CIP .223 pressure is about the same as 5.56 NATO standards. You're going to have absolutely no problems shooting 5.56 labelled ammo out of your SL8.
For example, European produced 223 ammo like Sellier & Bellot 69gr which I've tested and chronographed quite a bit is loaded hotter than 90% of 5.56 labelled commercial ammo here. In fact it's probably the single hottest factory load I've found aside from Hornady Superformance 5.56
I've literally shot hundreds of 5.56 labelled ammo out of SL8 with no issues at all.
And again, European 223 ammo is EVEN HOTTER than the 5.56 ammo you find off the shelves here. If you truly believe that you cannot shoot 5.56 out of your barrel in 2024 then you better not buy any ammo manufactured in Europe
It is not a question of hotter. The concern was about chamber dimensions.
If you buy a rifle, do you know the actual dimensions to which the chamber was reamed? Are manufacturers using a chamber drawing suitable for both .223 and 5.56x45 ammunition? It would make sense for them to do so - and their customers would never know the difference.
If you buy a rifle, do you know the actual dimensions to which the chamber was reamed? Are manufacturers using a chamber drawing suitable for both .223 and 5.56x45 ammunition? It would make sense for them to do so - and their customers would never know the difference.
They interchanged just fine in the 70's the interchangeablity issues came along with the internet
Sure, I'm sure there exists some reaming hackjob chamber out there that would cause significant overpressure with even 5.56 labelled ammo. That's more to do with improperly made chamber than anything else.
In the case of the SL8 (and HK barrels in general like on MR223 and MR556,) they are notorious for having lower chamber pressures and lower muzzle velocities compared to 5.56 barrels of the same length. This is true for my SL8 as well. If you use a normal AR throat erosion gauge in even a brand new HK barrel you'd get a result of the barrel already being full worn out.
Beyond that, HK clearly took safety very seriously when they designed the SL8/G36 because it has two further redundancies to prevent catastrophic failure from overpressure, namely the many flutes cut around the barrel and the pop out plugs under the receiver.
the interchangeability issues came along with SAAMI, not the internet.
So the chinese ammo that many owners shot without problem, depending very heavily on how you define "problem." My experience with the ammo is that I was very glad I didn't waste my money buying a crate, and several of my friend's experiences were such that they severely regretted that they did. One misfeed per 5 round mag and abysmal accuracy might be fine for people who just like blasting dirt or CQB distance targets, and people who never shoot through their doomsday stockpiles never have any problems at all.
Just ask the manufacturer. One thing some people may have missed is WARRANTY COVERAGE CONDITIONS. Some manufacturers bury in their warranty fine print that using ammo they don't approve of (in this case 5.56 NATO and/or Bubba's mystery .223 pissing hot) voids the warranty. Even if the gun shot that hotter round "just fine" and made Bubba proud... your warranty coverage may not be "just fine" after that.
All manufacturers would be putting in some excess engineering tolerance. The better ones will build in a higher tolerance for safety and reliability purposes. Simple example - there are manufacturers that actually sell "9mm +P+". If you ask B&T they will say NOPE. Their answer is: "only shoot factory-loaded 9mm +P at most". I have a strong hunch the guns were built with a generous enough engineering tolerance they may shoot +P+ but say goodbye to your warranty.
What manufacturers DO NOT want buyers to do is push the gun to levels they consider from their technical AND legal standpoint to be unacceptable risk. Shockingly enough gun companies like other companies and individuals do not like being sued or bad PR.
Tl;dr - Ask the manufacturer if confused to protect your warranty. Get it in writing.
All manufacturers would be putting in some excess engineering tolerance. The better ones will build in a higher tolerance for safety and reliability purposes. Simple example - there are manufacturers that actually sell "9mm +P+". If you ask B&T they will say NOPE. Their answer is: "only shoot factory-loaded 9mm +P at most". I have a strong hunch the guns were built with a generous enough engineering tolerance they may shoot +P+ but say goodbye to your warranty.
What manufacturers DO NOT want buyers to do is push the gun to levels they consider from their technical AND legal standpoint to be unacceptable risk. Shockingly enough gun companies like other companies and individuals do not like being sued or bad PR.
Tl;dr - Ask the manufacturer if confused to protect your warranty. Get it in writing.
redshooter
CGN Ultra frequent flyer
- Location
- Central Ontario
Anyone buys a new rifle they should shoot 40 rds of factory (in the proper cartridge), stick the brass back in the box, put a note on it, and set it aside for the warranty period.
Obviously not a problem if you don't reload, but in the 5.56 vs 223 argument, once you have your handful of "this is what I've been shooting", as long as you have no pressure signs I'd be quite comfortable shooting 5.56 going forward.
Extra spicy shouldn't blow up a gun, wrong powder, or obstruction does that.
Obviously not a problem if you don't reload, but in the 5.56 vs 223 argument, once you have your handful of "this is what I've been shooting", as long as you have no pressure signs I'd be quite comfortable shooting 5.56 going forward.
Extra spicy shouldn't blow up a gun, wrong powder, or obstruction does that.
Oh. A calculating strategy there on how to handle the warranty coverage issue. I'd also say too much of even the intended powder can also blow up a gun. Still one of the best memes ever:
Imagine if that person took the shotty back to manufacturer and was like: "I was just shooting some factory low recoil buckshot... I have no clue what happened here!"
