I saw that Wes is selling full auto bolt and carrier groups with the Crane extractor mod for $250.  I did a search but came up with nothing.

What is modified, and what does it accomplish?

Thanks

If thats all it is why in the world is it more than twice as expensive as a Bushmaster M16 Bolt/Carrier?

Thanks Wes.  I figured you'd be one of the first to answer this.  [:)]

The reason I didn't simply ask you is because, after doing my fruitless search, I figured it would be best to start a thread with a searchable title for others to find in the future.

I thought that this might be a newly designed bolt with the extractor and spring in a different configuration so that centrifugal force doesn't fling the extractor open anymore.

Can you tell what the inside diameter, outside diameter and thickness of the O-ring is?  I ask because I did this mod to my extractor about 2 years ago with a 13 cent ring from the hardware store.  It throws the brass at about a 45 degree angle behind me and I've been starting to wonder if the o-ring is too thick.

BTW, I clean my bolt with brake cleaner and after X-thousand rounds and several cleanings in the last two years, the O-ring still looks brand new.

Is this the same thing as the D-Fender?

Les Baer Custom chromed bolt carrier (formerly Young Manufacturing).

You can buy the O-ring at Home Depot and get 200 or so for 3.00.  I have a friend who has the same one installed for about 5000 rounds.

John

Understood...

Crane made a presentation last week in Kanas City about their successful 10" CQB Carbine program.  They briefed a new "5-coil" extractor spring in lieu of the standard 4-coil.
They did not mention any "o-rings", but did say the 10" upper incldes the "one-piece coil gas ring", and it looked by the test data they were replacing gas tube at about 5,000 rounds.
ColdBlue was there...