Posted: 4/12/2002 5:34:27 PM EDT
| I am relatively new to this. what is a sear block? what does prevent/allow me to do? and if I want to buy a preban lower and put a new M4 upper on it, what do I have to look for? any help is greatly appreciated, even if someone could give me a web address. thanks! |
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sear block is what colt came up with to prevent you from putting in a drop in auto sear, or auto sear.I think colt is the only company doing sear blocks. Not sure what you mean by what to look for. a sear block wont prevent you from putting on different uppers, only your bank account will. If you have a preban lower and want to put a preban m4 upper on, just r & r. |
| If you have no plans on converting it to full-auto with a drop-in-auto-sear, then the sear block will have no detrimental effects at all. Some people say the sear block unintentionally prohibits the installation of a match trigger as well, while others claim that it does not. My pre-ban Colt lower has the sear block and I have no intentions of removing it. If your lower has the "large" pivot pin, then you will need an adapter to mate a "small-hole" upper to a "large-hole" lower. If it has a sear block, it probably has the small pivot pin and they will mate up fine. All rear takedown pins are "small". If the pivot pin is the same size as the takedown pin, then it is a "small-hole" lower. Hope this helps. |
| The sear block in my preban Colt prevents me from swapping to a fixed stock; the buffer will not clear the sear block to install in the buffer tube. This sucks, as I wanted to be able to change things around. Maybe I should trade it for a different brand preban. |
that's odd, it works great in mine. it just slides on in. |
This doesn't make sense. I have swapped back and forth between full size A2 stocks and M4 collapsable stocks on my pre-ban Colts with the pinned in style blocks. Countless others have done this as well. You have to work them over the block a bit, but both the rifle and carbine length buffers go in and out with relative ease. I don't understand what your problem could be. And if all else fails, as already suggested you could simply install the buffer and spring at the same time as the buffer tube. |
I'm going to guess that your gun is a R6520 blue label, as the chances of finding a blocked gun with a collapsible stock on it is rare (other than the R6520 Blue Label). If I'm right, I'd not bust the factory staking of the retention ring. You'll only decrease the value of your investment. If you don't care about those things, do as the others have suggested. |
Did the R6721 AR-15A3 Tactical Carbine have the sear bolck, too? |
