An opportunity came, and I jumped on it.  I have an Omega MP5 clone arriving next week, and now I feel the need to start loading to feed it.

Do I need to do anything special in handloading ammunition for a fluted chamber firearm?

I've seen various takes on reloading brass that has been fired in fluted chambers.  Broadly stated they are either "the brass is fine" or "the brass is trashed."  I've inspected a bunch of brass that was clearly fired in fluted chambers, including 9mm, 5.56mm, and 7.62mm, and I haven't seen any reason this "brass is trashed."  But I haven't loaded a ton of it, nor loaded any a second or third time, so I have no personal experience.  Is there anything to the "brass is trashed" argument?

Your brass will be striped but it's fine to load.

I know it's not quite the same but my PTR91 roughed up the brass pretty good during ejection. Sometimes notching the mouths or severely denting the middles. Usually was fine after sizing.

Needless to say I wouldn't use brass that you care about reusing frequently.

Scout, I've seen "roughed up" fluted brass on the range, and I've seen AK .223 brass...AKs seem to like to chew cases pretty hard, while the fluted cases I've seen were dented more than I'd expect from an AR, that's all.  It's good to know my observations are consistent with other people's.

dryflash3, I think I've seen brass that was once fired in an H&K then reloaded and fired in a conventional chamber.  The flutes are less prominent with these.  I've also found brass that had marks that looked like it had been through fluted chambers more than once - it was interesting to see overlapping stripes.

I'm pretty confident that I'm not going to have to buy tons of new 9mm brass, and thanks for helping reinforce that.

I won't be able to take the thing to the range until next weekend (at the earliest), but I plan to run some factory stuff through it to break it in.  Probably PPU-made "Monarch Brass" brand off-the-shelf stuff for the sake of cost.  I'm probably overthinking this, but if the Omega clone is as close as possible to a factory MP5 in terms of bolt weight and barrel length, it seems that anything that would be anywhere near NATO specs should run fine through it.  But...  I'm also going to have a whack at it with good old, wimpy Winchester White Box 9mm as well, just to see.  That should tell me if I need to tinker with a basic load or not.

The best thing a HK 91/93 shooter can do is get a port buffer. This helps with damage done during ejection.  Always liked to see Federal Match 308 (back when it was loaded with nickel plated brass) that was shot out of a HK91.  It reloads just fine, but a if you are regular user of a HK 91 clone etc.  I would want to be using IMI, Lake City, or other heavier brass to prolong case like.

9mm brass from a fluted HK chamber tend to be mostly soot striped,, unless super pressure load that apply case wall to flutes to imbed marks..

Wash them good to aid in losing the carbon stripes, then carry on as usual with loading

Attached File

Unless it’s a trick of the lighting, those are nickel plated cases...  That makes me feel much more comfortable with loading for the MP5 clone.

I’m not planning to get anywhere past NATO power levels.  That’s about 1200-1250fps out of an 8” barrel, which is certainly doable comfortably without uber pressure issues.

No sir,, them be Blazer aluminum.. there been fella in past come out with MP5 variant and litter in the front of fire line with both brass and aluminum cases..

Even better!

Ive picked up plenty of brass fired from fluted chambers.  No issue with it at all.  Post wet tumble, the soot is gone from the case.  It sizes fine.