BCG dissection

[Scouttracker]

I found this great video from
School of the American Rifle.
Its about 14 minutes long, but worth watching , it's called.
FAIL ZERO AR-15 BCG AUTOPSY

[dpete]

Link?

[mdram]

https://www.youtube.com/watch?v=CrJl3LThLFw

[Scouttracker]

https://www.youtube.com/watch?v=CrJl3LThLFw

Thanks I was having trouble posting the link. I'm technically illiterate.

[LRRPF52]

[montana]

BCM created their own air gauge tools to test their BCG's 3 bores..https://www.youtube.com/watch?v=BaFOZAwspYI

[Rivercityjeff]

Thanks! I went down the rabbit hole with a bunch of their videos.

[Vin]

BCM created their own air gauge tools to test their BCG's 3 bores..https://www.youtube.com/watch?v=BaFOZAwspYI

While a pressure check can tell you the current gas efficiency of your BCG, tail, rings, etc - what it cannot tell you is its wear as a predictor of failure or indicator of need for replacement. Physical measurements with pin gages and micrometer are the best way to perform PM checks of these parts.

[montana]

While a pressure check can tell you the current gas efficiency of your BCG, tail, rings, etc - what it cannot tell you is its wear as a predictor of failure or indicator of need for replacement. Physical measurements with pin gages and micrometer are the best way to perform PM checks of these parts.

Pin gauges are not fool proof as some poorly machined bolt tail bores will pass the pin gauge test, yet when viewed by a bore scope and back light, the bore hole can be out of round that an air gauge would find..The same principle for using a taper gauge for the firing pin and cam pin hole with the bolt..

[LRRPF52]

Pin gauges are not fool proof as some poorly machined bolt tail bores will pass the pin gauge test, yet when viewed by a bore scope and back light, the bore hole can be out of round that an air gauge would find..The same principle for using a taper gauge for the firing pin and cam pin hole with the bolt..

[LRRPF52]

Another great video from School of the American Rifle:

Notice how the gimmicks are way downstream and the BCGs that adhere to the TDP have the best gas system efficiency.

[Clintster]

Both were well worth watching. Really found it interesting in the first video the mention of lose primers going into the gas key port... just happened to me about a month ago so maybe more common than I thought it would be.