My father in law just opened a colt ar-15 sporter hbar ser # early 20000's brand new and we were going to try out a tac trigger on it but when we charged the weapon the trigger would not fire. When we would turn the saftey from fire to safe we would here a small click inside the trigger housing area and then when we would place the safety back on fire the trigger was then able to fire. Each time we would charge the weapon it would not fire unless we turned the safety to safe then back to fire each time. Upon opening it up we noticed a small lever under the hammer that is catching the hammer each time it is charged and as we turn the safety this lever moves backwards very slightly just enough to allow the hammer to click up just a small bit to its normal position thus being able to fire. also there is a big metal block in the u shaped cut out area behind the hammer and in front of the buffer assy that is stamped colt is this the block that prevents you from inserting the full auto sear? any help will be greatly appreciated.

From what I understand, the TAC trigger has NOT been installed yet, and the weapon is new, and stock from the factory.

 If this is correct, here's what to do:

take the upper off of the lower
with the weapon on "fire," manually move the hammer to the cocked position (all the way back).


pull the trigger

if this works, keep the trigger pulled all the way back, and manually cock the hammer again.

release the trigger- you should hear a slight "pop"

pull the trigger- the hammer should fall

if this works, we isolated the problem to the assembly of your bolt carrier group.  Here's what you do with that:

make sure that the firing pin retaining pin is there, and fully inserted.  

with your hand, push the bolt into the bolt carrier

give a good hard jerk, and ensure that the bolt moves freely in and out of the carrier, with no restrictions.  

thoroughly check the inside of the upper receiver, as well as the lower receiver for any debris or large pieces of grit.  

Keep us posted, and don't be afraid to ask questions about anything you are unsure about.

Also, when you reinstall the firing pin retaining pin, even thought it LOOKS like a cotter PIN, do not spread the ends.

When installed properly with the rounded end on the left side of the carrier and the split end on the right side, where the notches / serrations are, the upper will keep it in place.

It is brand new and has never been out of the plastic until yesterday. It is assembled properly and is clean as well. When we charge it there is a small lever infront of and below the sear block and when the hammer goes back as in being charged the lever catches the hammer and it will not fire at all untill we turn the safety lever from fire to safe then back to fire. as soon as we move the safety switch about 1/4 of an inch or less the lever moves just slightly to the rear and upwards sort of and the hammer then makes a click as it rises about 1/4 of an inch to its normal place and then we are able to pull the trigger.

sounds like something is sticking there- this should work itself out after firing a few dozen rounds

you can expedite the process by lightly spraying the action with some RemOil or other aerosol lube.  Just remember to blow or wipe out the excess when you are done!  Keep us posted- good luck!

from what you are saying is almost sounds like you have an m-16 fire control group and sear, but an ar15 carrier.  but you would have to move the safety past the fire slot to activate the sear..

i don't think this is the case though, obviousely..  

please post some picks if you can..

It's the disconnector!!!!
Really, it is.

It has an over developed sense of responsibility in keeping your rifle from slam firing.
On a working ar-15, this is what holds the hammer away from the trigger until the triger is released.  When you release the trigger you get the same click.

To fix the problem, you need to remove the hammer, and then pull the trigger pin slightly out until the disconnector is free.  The part you see catching the hammer is a little long.  
If you hold it in the same orientation it would be if you were firing your rifle, (upright, like its still in the rifle) then you can stone the hook part thats catching, perpindicular to the ground, a little at a time, reinserting, and checking for clearance.  

Or, send it to a good gunsmith,(many recommendations can be found here on the board) and let them install a match grade trigger. You'll love your rifle so much more with a perfect trigger.

HTH

WL


edited for typos

It needs a drop in safety sear.

Hey dork why don't you look here?

[url]http://www.ar15.com/forums/topic.html?id=101654[/url]

thanks for all the good info
i will let u all know how it turns out when i test it and if its not positve then i will take pics and post

Ok Bill, I told ya you need to trade that Pre ban POS for my post band Bushmaster. Quit dragging your heals and unload that nightmare on me! [:D]

LOL
you are a funny guy and I bet you would evenlet me pay you some cash to amke up the difference in the trade huh
by the way I found the range in sapulpa it is $7 per day to shoot there and they have a pistol/rifle range with berms at 10, 25, 50, 100, 200 meters