CZ Bren 2 Ms Carbine 5.56 Ammo

[BoommooB]

I've fed at least 30 different types of ammo through my CZ Bren 2 Ms Carbine 5.56 16.5" (not pistol) and seems like it doesn't like steel Russian ammo among others. I had a good number of failure to feeds from the following ammo but consistent feeds with other ammo.

TulAmmo .223 55 Gr. FMJ
Wolf .223 55 Gr. FMJ
Red Army Standard .223 55 Gr. FMJ
Fiocchi .223 55 Gr. FMJ
PMC X-TAC 5.56 55 Gr. FMJ
Armscor M855 50173 Green Tip 5.56 62 Gr. FMJ

What are others seeing? I was expecting a former communist bloc country to play nice with commie ammo but doesn't look like it. A bit disappointing considering the price of this platform with other platforms being able to eat everything from the "buffet" of ammo.

[Bret]

You're indicating failures to feed, but all of that ammo has pretty basic profile. What ammo is working successfully? Are you sure that the rifle is cycling enough gas? Are spent cases ejecting before these failures? How far are they ejecting? Does adjusting the gas system impact the ejecting and feeding?

[BoommooB]

Over a couple dozen other kinds/brands of ammo work flawlessly from 50 gr. Black Hills 5.56, 77 gr. .223, Federal & Gold Dot "duty" ammo, "better" PMC, 55 gr. range Federal/Winchester, etc. The piles of ejected casings end up in same general area and gas system working except for the ones listed. There's only an off, normal and suppressed setting. The off turns it into a bolt action.

I'm not finding much info so I'll just steer clear of what hasn't worked reliably. Glad I don't have much TulAmmo left and will get rid of it this weekend.

[MountainRaven]

There's only an off, normal and adverse setting.

FIFY.

[BoommooB]

Quote Originally Posted by BoommooB
There's only an off, normal and adverse setting.
FIFY.

You're obviously not an owner of said carbine variant. The carbine doesn't have a 2 position but a T which is suppressed.

The manual on their website is wrong and only for the pistol version. CZ being lazy and didn't bother with a carbine specific version with several other differences.

[Aries144]

My 14" 5.56 Bren 2 doesn't like Serbian Prvi Partizan M193 without a suppressor attached. I see malfunctions where hammer falls on an empty chamber (meaning cases are being ejected, but bolt isn't going quite far back enough to pick up the next round from the mag). Switching to "adverse" gas setting restores function with that ammo.

Prvi Partizan M193 has similar velocities to other M193, but the older stuff was known to use propellant with a different pressure curve than most M193. AR15s didn't like that stuff either.

[MadAngler1]

Have you tried IMI?

Surprised to hear that PMC Xtac was not working. I’ve never had issues with them (55 or 62 gr).

[Circle_10]

That’s an interesting assortment of ammo to have failures with. Ranging from Russian steel case, which is frequently a little weak, to brass cased M193 5.56, which should be reasonably hot.
I know next to nothing about the Bren 2 but figured I’d throw this suggestion out there. Are you sure it isn’t a magazine issue and the loads that you had failures with just happened to be getting fed out of the same trouble-prone magazine(s)?

[Bret]

BoommooB, Are spent cases ejecting before these failures to feed? How far are spent cases ejecting when using ammo that runs reliably?

[BoommooB]

Three Russian steel cased (known for issues on other platforms), one Italian, Korean and Filipino. I was surprised with Fiocchi and somewhat with PMC. Looking at the Armscor boxes having labels placed over boxing was a little suspect. No issues with magazines as they're cycled through and used successfully.