I have a preban colt ar15.  Its a slabside, large pivot lower.  It has a sear block.  Here's my question....

Does it have large fire control pins, easy sear block to remove?  I mean i dont understand the fire control pin stuff.  What is/are they?  Please explain........


thanks

Orion, the fire control pins are those for your trigger and hammer.  You can measure them to check the size if you have a pair of calipers.  Push one of them out just far enough to measure.  The small pins will be about .154 and the large about .170  I am guessing you have a blue label with the large pins if it has a sear block.  If the sear block is pinned then it can be removed fairly easily by a competent gun smith.  Otherwise, it will have to be milled.  If you are pretty skilled there is a hydraulic method of removing the sear block pin by drilling, tapping and using oil to force out the blind pin.  I do not have the procedures.  They may be posted on the board somewhere.

Thank you fox.  I am not really interested in removing the sear block.  I was just curious about the pins.  What is military spec?  Large pins or small pins?  Blue lable....I was thinking i had a "green" lable....  All of these lables are silly.  Anyhow, thanks again.

Mil-Spec is the small pin version.  I do not recall any green labels having sear blocks, and IIRC, all green labels had small fire control pins.  The sear blocks came with the blue label series.  The early blue label rifles had slab sided receivers.  Green and blue label refers to the shipping label color on the original factory box.  There were white, black, green and blue.