AR Sponsor
Posted: 12/22/2007 4:10:44 PM EDT
|
First let me appologize for buying a Colt. (I swear I didn't know). I purchased a Match trigger today and when I went to install it, the colt receiver block is in the way. I have read that some colts have one pin and a roll pin holding it in some have two pins which may be counter sunk or not tapered or not may have roll pins or not , and some having three pins and roll pins or not. Mine has two pins, which I understand are put in blind holes, the diameters of the pins on the reciever outside are .187 (3/16). I have seen pictures on the net of these blocks that have a hole visable in the top for the roll pin. My rifle does not have this pin hole. Is it posible that the pin was put in from the bottom or did they use a double blind hole by puttin in the role pin and then tapping the block down from the top? I plan to remove the block so I can install the new trigger but if anyone has a rifle in this configuration I would appreciate a heads up about the pins. Are they all counter bored or are some just straight pins. On the counter bored pins, what is the smaller diameter of the two?. If there is a hidden roll pin, is it in the same location and what is the diameter? I have access to an EDM machine that can take care of the pins and the block at once without any risk of damage to the receiver but it is slow , Or I can use A Bridgeport mill with sharp Carbide endmills but if they break it will be over to the EDM anyway. If the side pins come out I can make some pins to fit with enought press to keep them in but for folks who want to plug those holes with the original pins, try locktite's bearing lock, You won't get that loose again. |
|
I have a Colt with the block. I took that into account when I bought a replacement trigger- and they do need replacing. I installed a RRA match trigger tuned by White Oak Armament. The pins were no problem. If you are trying to install a trigger that is a single unit you will need to dremel out the block or take it to a machinist to have it milled out. Which trigger did you buy? Jim |
| I just dremeled my block out. It had two pins. One on the ejection side of the receiver and one sticking straight up into the block. I figure they press the block down onto the vertical pin, then pin it from the side during assembly. I used a cutoff wheel to cut the side pin, then rocked the block back and forth until the vertical pin snapped. It came out well with only a tiny nick or two in the anodization. My side pin stayed put in the receiver, which is nice. I wouldn't want a big hole there. |
|
well I bought a rock-river arms two stage match trigger. I really just wasn't thinking about the extent to which the reciever block prevented the use of naughty parts. I was thinking it prevented the installation of a full auto sear, and the use of a military bolt carrier. The basic trigger area wasn't even on my radar. The only thing about triggers I was thinking about was the .156 pins verse the .170 pins (mine are the small pins). Eventually I will also put on a free float tube, 1/4 click sights and maybe a match grade barrel, though honestly the current one shoots amazingly well. I manage 1.0 with handloads and a scope mounted on it. though I don't have one of those add on check rests that make a using a scope on this model semi practical. The current trigger isn't bad for a infantry rifle, but for match use it could be better. Hence, my current problem. I have seen threads showing removel of the block using one side pin using a dremel. but have a two pin model. Though I am not a gun smith, I am a machinist, so I can use a mill with carbide drills or carbide endmills. Likely, a combination of both. I still have no idea how hard the block is. though I heard the pins are hardened. so drilling into a metal of one hardness and running into another (the pin) is a recipe for breaking the drill in the hole. Even a High speed steel drill is very hard so removeing it from the hole it is stuck in is very very difficult. I can use a small die sink EDM machine but I have to remove the buffer tube to get it in the EDM tank. A Graphite rod burns through the block and pin with electricity. I only need to go deep enough to get though the pins. I can push the pins out and remove the block. I have read that pushing out some pins can raise a burr around the hole. but I have also read that the pins are a press fit in the block but not that tight in the reciever. (makes me rethink my whole geometric positioning theory). Once I remove the pins I can EDM or Mill/Drill down to the vertical pin to relieve it somewhat. then remove the block. The just for the heck of it I am going put it on the hardness testor and find out just how hard it is! My goal is to shoot CMP service rifle matches. I really didn't want to have to sell this one and buy another, considering I will likely loose money. While I may have some trouble with the block, I trust the geometric positioning of the reciever features are within tolerance. I Won't be attaching any doodads, "laser's" (a little Dr. Evil lingo there) or stuff like that so even the front take down pin being a odd size and not a push pin is no big deal. This rifle is a range queen. I wouldn't mind getting one of those M4gery's for some fun. (olympic arms is about 5 miles from here) but I use an old RCBS Rock chucker to load my ammo and I work so hard to make it I hate to burn it up too fast. |
|
Argonaut, why are you trying to remove the block? Just to install the trigger? It's not necessary. I bought that same trigger and my rifle has the block. I didn't have to remove the block- it's still there. I'd hate to see you go through a lot of trouble for nothing. Jim |
|
really? it fits. it really doesn't look like it fits. it looks to wide with the block in the way. the current trigger has sort of a lever about 3/32 wide the slides past the block on the right side. my new trigger doesn't have a reduced area at the rear portion of the trigger. it is full width to the end about .275 in width and 1.270 inches from the pin center to rear end |
I don't remember exactly what mine looked like, but there was no problem replacing the trigger. The block does make it a little annoying, but not too hard. Are you sure you ordered the correct trigger? They have one for a Colt with large pins and the block. Jim |
|
I wouldnt mess with it... you have the trigger.....just get a new lower and put another one together.......... but then you would have a lower just sittiing around...............and we all know what happens to them...............they get a new upper put on them...............BRD 
|
AR Sponsor