Noveske 9.5 .300BLK Upper Chews Up Brass

[TheHorta]

Got this upper about 3 years ago from a fellow Hider. Popped it on my N4 lower and put a few rounds on it. It seems to run and cycle just fine with both subs and supers, BUT…

It shreds brass bigtime. After a single mag, the chamber is filled with brass flakes unlike anything I’ve ever seen. Almost like you took a cheese grater to the casings.

Whaddup?

 

[loveha]

Feed ramp have a burr? Would pop the barrel off and smooth it out with cratex tips if so.

 

[TheHorta]

Not that I can see, but will try to take some macro photos.

 

[Aftermath]

Feed ramp but also the other side of the locking lugs might be peeling brass during extraction. I'd take a fresh piece of uncharged brass and feed it from a mag with the charging handle and buffer spring. Then start looking for brass shavings looking for if it's peeling on insertion of the cartridge or during extraction...maybe it's both...either way, I'd be for taking the barrel out and start feeling around for sharp edges.
Also, I have used sharpies to index a round as I feed it so I have a pretty good idea where I should start looking for the offending sharp edge.

 

[hlee]

What do the cases look like?

In the current absence of pics, I’m just going to throw out the possibility that what you are seeing is unburned powder left in the action- which seems to turn yellow in the event that it doesn’t burn when the cartridge ignites.

 

[TheHorta]

What do the cases look like?

In the current absence of pics, I’m just going to throw out the possibility that what you are seeing is unburned powder left in the action- which seems to turn yellow in the event that it doesn’t burn when the cartridge ignites.

99% sure it’s brass. I’m seeing scrapes on the casing after eject. Need to see if it’s happening during feed, eject / extract or both.

 

[1911hombre]

Have you tried different mags? Crazy as it sounds I have seen some lowers that will do what you speak of with certain types of mags...I would pin it to a different lower for starters.

 

[roostercogburn98]

Your rich, throw it away and grab one of your other ones from the safe

 

[LRRPF52]

Biggest factors in shaving brass are:

1. Extractors with sharp corners on the lips. They need to be toned down and polished.
2. Ejectors with sharp edges
3. Sharp Extractor shelf/bolt face ledges

Once those areas are cleaned up, brass shavings go away. Some pics of your brass would help, especially with angles showing what the rims look like from behind and the front, as well as the case heads.