I don't know what to make of these....

[ageingstudent]

I bet those chambers are a lot of fun to clean.

 

[Stomper]

So new cartridges do not have the ribs on them?

Did you REALLY just ask that question after all that discourse and explanation?

 

[ron]

It's actually superior German engineering for the application it's meant for. The weapon has a delayed locked-roller blowback system, and fluting allows the hot gasses to "float" the spent casing out of the chamber making it an incredibly reliable method of extraction. Even if the extractor breaks, or a casing shears off in the chamber, the chamber gets cleared 99.9% of the time.

That's an AWESOME feature for a assault/battle rifle.

Superior? NOT Much more recoil in the delayed locked-roller blowback
design. Compared to a M1A.

 

[Tully Mars]

Superior? NOT Much more recoil in the delayed locked-roller blowback
design. Compared to a M1A.

Really? Because I've never noticed it. To me at least, no difference in felt recoil in my HK's, CETME and my M1A.

 

[Caveman Jim]

Did you REALLY just ask that question after all that discourse and explanation?

I did?

 

[Stomper]

I did?

 

[Caveman Jim]

Thank Pal, first time I ever got the "Beat a Dead Horse" prize, I'll covet it....

 

[etrain16]

They're ribbed, for your pleasure

 

[Ura-Ki]

Superior? NOT Much more recoil in the delayed locked-roller blowback
design. Compared to a M1A.

Correct, Way more inertia in the bolt assembly and unregulated gassing to the bolt face equals a noticeable increase in recoil

 

[elsie]

So new cartridges do not have the ribs on them?

Not that I've been able to find.

But then, I haven't really looked for pre-ribbed brass. B-)


elsie

 

[elsie]

I wondered about this. I didn't think "fireforming" would take all of the lines out.

It makes the fade a bit with each firing, but they tend not to disappear.


elsie

 

[elsie]

I bet those chambers are a lot of fun to clean.

It's about the same as an AR or any system that uses gas back to the chamber.


elsie

 

[Ownerus]

The Soviet SVT40 Tokarev rifle also uses a fluted chamber, predating the HK by a bit. Another example of the fluted chamber is the HK P7 pistol, the gas-delayed blowback 9mm.

A fluted chamber is sort of a variation on the lubed ammunition required for a lot of early machine guns and rifles like the Pedersen competitor for service rifle when the Garand was adopted. Guns that don't actually lock solid for a period of time as chamber pressure drops or that don't long enough. When the breech face can start moving while the case is still under high pressure, if the case is not lubed or "floated" as in the instance of a fluted chamber, case head separations can occur when the head of the case starts to move while the body is still stuck to the chamber walls.

Cases fired in fluted chamber can be reloaded but I doubt it does anything to enhance case life. And, they're never gonna be "pretty" again

 

[Camelfilter]

Although your question is well on answered, here's some pics from a few months back of some fluted brass cleaned up (not sized, I'm not there yet).

I gave them away, not sure if the taker is reloading either as if yet.

Hertenberger surplus.

Fired thru a Century CETME, picked up wet and stored in a ziplock (dohhh!):



Figured I'd play with my roller and stainless media to see what it could do:



Came out looking really good. Note you can see the ejection port dent on several. Our other G3 type rifles (PTR) have ejection port buffers. It's a rubber bumper which limits the dent & reduces the "fling" a touch.

 

[Caveman Jim]

They're ribbed, for your pleasure

Or hers.....

 

[Caveman Jim]

Well boys & girls I have found a dozen or more of these casings today and have about 2 dozen total, does anyone want them?

 

[Ownerus]

....some pics from a few months back of some fluted brass cleaned up....

Wow! I'm impressed. I've never seen fluted chamber brass clean up that well. Looking closely, I can't see any remaining evidence of the ribs from the chamber flutes. Well done!

 

[Camelfilter]

Well boys & girls I have found a dozen or more of these casings today and have about 2 dozen total, does anyone want them?

Check to see if they are boxer or berdan primed. A lot of folks, ourselves included chuck a lot of surplus thru these rifles. Some of the surplus we have is boxer primed, but a whole bunch is berdan.

Boxer vs Berdan (interwebs photo):




Most folks will not bother with berdan primed brass, as they are more complicated to decap.

Also, if surplus, they will be crimped. Not too big of a deal, but ads a step or a process.

All those pieces in the pic above of the ones I cleaned up had the 3 prong crimp on them, but swaged out nicely. I've a pic up on here (somewheres...) on how they come out swaged.

Found the pics I was thinking on. From a thread I asked on how to go about prepping that brass. Tons of great responses, I went with a Dillon Super Swage.

Decapped, with crimps still there:



Crimps all nicely swaged:



Even if no one wants your pickups, they are still brass so do hold some type of recyclable value.