Bolt over base in new LMT MRP

[MWT]

I purchased an LMT MRP complete rifle last week direct from LMT, took it home, cleaned it thoroughly and lubed it up with ALG Go Juice.
During the first 60 rounds fired, I experienced 3 bolt over base malfunctions (Federal XM193 5.56)
At approx round 240, I encountered another bolt over base. (Federal American Eagle .223)
Current round count - 260rnds.

Magazines were 3 new Lancer 20rounders used randomly. No malfunctions in new Lancer 30rounders.
Rifle is a stock LMT, with the LMT ebcg and 16" mid-length stainless barrel & car buffer. Stock A2 flash hider.

I never experienced a bolt over base in any of my BCM or PWS rifles, so I have little idea what I should do. Re-clean it? Run 200 rounds more to break it in?

[17K]

I just went through this with myself.

I file 13'd my mags and tried again with new Gen M3s. Problem solved.

[LMT Shooter]

It MUST be the mags.....

[LMT/556]

Why are you running an ebcg? I bought my MRP with an L7D3, never a feeding issue with Okay mags, did break an ejector coil pin though.

Come to think of it I did have an odd issue with it not locking back, I think the carbine buffer is way light and replaced it with an H2, not a hiccup since. During this early period I remember firing a round, it ejecting, the bolt closing and click, nothing in the chamber. Coupled with the bcg not locking back my thinking was occasionally the bcg was moving too fast to pick up the next round, or lock back after the last round. I went H2.

[LMT Shooter]

I can't recall if LMT told me to use an H or an H2 buffer, but I believe that they told me not to use a std CAR buffer with a 16" barrel mid-length gas tube/enhanced carrier combo.

And I only bought the enhanced BCG because it was on sale for less than the std BCG.

[MWT]

- Ordered a Geissele Super 42 with an extra tungsten weight.
- Numbered all mags and will catalog malfunctions (if they appear)
- Rifle came from LMT with CAR buffer & EBCG - I changed nothing (thus far)


Thank you guys for the input!