Sealant between carrier and key?

[Pappabear]

I have a NIG colt BCG that has goop dripping out.

[markm]

I have a NIG colt BCG that has goop dripping out.

That's NAM juice.

[koniz]

When building hundreds of BCGs at LMT we never used anything on keys just bolt and stake, and that's what I still go by and never had any issues.

[markm]

When building hundreds of BCGs at LMT we never used anything on keys just bolt and stake, and that's what I still go by and never had any issues.

Shocking that a company who used MIM gas keys at one point would also not seal.

LMT cuts a lot of corners and that's why I don't use any of their products in critical areas.

[T2C]

I have been repairing AR-15s for several years and did not know I was suppose to be using sealant. They did not mention it when I went through armorer school and I haven't seen an issue caused by not using sealant.

The machining looked pretty rough on some of the M-16s our agency received from the Department of the Army. You have to wonder if the parts were not as precise or fit as well when Colt published you should use sealant.

[koniz]

Outstanding good for u markm

[markm]

Outstanding good for u markm

Thanks... I mean... people like the stuff, but why bother when you can get BCM for equal or less money, and it's done to spec. Makes zero sense to me.

[koniz]

You do have a point

[markm]

I have been repairing AR-15s for several years and did not know I was suppose to be using sealant. They did not mention it when I went through armorer school and I haven't seen an issue caused by not using sealant.

Most people don't know it. And if the surfaces are smooth, it's not an absolute must.

[Magic_Salad0892]

Shocking that a company who used MIM gas keys at one point would also not seal.

LMT cuts a lot of corners and that's why I don't use any of their products in critical areas.

You say LMT cuts corners, but have you ever seen a catastrophic failure from an LMT gun as the result of their manufacturing techniques?

I understand your sentiments, but like KAC not using HPT, in LMT's case it seems to work well. (Especially considering that their Enhanced bolt was the only one that survived the military trial.)