AR Sponsor
Posted: 4/12/2010 10:19:38 AM EDT
|
My machinist is trying to remove a Colt sear block from one of my shooters Colt lowers so he can get a Geissele trigger in it... is the pin that holds the block in a 2 piece pin? It looks to be a 2 piece since it looks to be tapered on both ends. Also my machinist was planning on drilling the center of the pin 1/2 way and seeing if he could push out the other pin (if it is indeed a 2 piece pin) but the metal of the pin is HARD!! any idea on the hardness of the pin? my machinst dulled 2 of his center drills in trying. Or... any ideas on how to remove the pin holding in the sear block?
Thanks!! 
|
|
The problem with the larger diameter tapered pins (that look like counter-sunk machine screws without a slot) is the ends will fall out after your remove the sear block so they're got to be glued into place.
ETA: Here's a link to an old thread on The High Road, I've got the pics saved and will email them to you if you PM me with your email address. http://www.thehighroad.org/showthread.php?t=216816 |
|
I once saw an thread, looooooooong ago, about drilling the block and using hydraulic fluid, under pressure, to remove the pin. The poster made it look easy. As memory serves, this poster remembers the method:http://thefiringline.com/forums/showthread.php?t=108921
I have a Milazzo-Krieger trigger, so the block was never an issue. Frankly, I'd just as soon the block remain in place. |
|
Quoted:
Raf, one of my ban era Colts has a Milazzo-Krieger trigger also. Have you been able to find another in the past ten years or so? I'd love to have a spare. Nope, they are apparently made of unobtainium, and customer service was, at best, surly. I underestand that some modern triggers might rise to the M-K level, but they might require removal of the block. It's of no concern to me. My M-K trigger is going on 25 years and doing OK. Keep it clean, and keep it properly lubed, and it will last. If I have to replace it, I'll look at what's available at the time. Till then, I'll be shooting with the trigger to which most others are compared––and few have really equalled..... if you haven't used an M-K, then you have no idea..... |
| The pins are separate and pressed into blind holes in the block. Good luck finding anything to mill or drill the block and pins as they are EXTREMELY HARD. About the only way to remove the block is to dremel or grind the block out, and then you can punch the pins thru after the block has been ground away. I would recommend not attempting this as it is time consuming and difficult. Leave he block in there, live with the trigger the way it is and buy another, non blocked receiver to put your nice triggers into. Trust me..... I am just trying to be honest and helpful. |
|
Quoted:
The pins are separate and pressed into blind holes in the block. Good luck finding anything to mill or drill the block and pins as they are EXTREMELY HARD. About the only way to remove the block is to dremel or grind the block out, and then you can punch the pins thru after the block has been ground away. I would recommend not attempting this as it is time consuming and difficult. Leave he block in there, live with the trigger the way it is and buy another, non blocked receiver to put your nice triggers into. Trust me..... I am just trying to be honest and helpful. For the blocks with the large diameter countersunk pins and maybe those with the three pins (right, left and left below the safety) I might agree. But, I've got a Colt 6520 lower that had a single small pinned block (right side only) professionally removed and the end of the pin left pressed in place in the lower and it's great. I assume it was cut out via the dremel method, and whoever did it did an outstanding job. There was a great thread with pics of this here a long time ago (and copied onto the Quarterbore.net forums as well IIRC) that detailed the operation, but I can't find it. |
|
You can remove the block with one single cut.
I removed my Colt's sear block a couple weeks ago. I generally followed the one thread where the poster used a Dremel and abrasive cutting disks. Was lucky mine only had one pin running into the receiver and block. I deliberately made the cut to leave a thin slice of block inside so the pin would stay anchored to the reciever. This is not a procedure for the impatient or those who lack attention to detail. It took me several days of slowly cutting, taking care to avoid damage to the receiver. The shaft of the mandrel contacted the receiver several times, removing some finish but no actual damage. Should have put some tape on the edge. Those sear blocks are HARD steel and forcing the Dremel wheel will just eat up disks. I just put gentle pressure on it and sometimes just let the weight of the Dremel do the work. Once the cut was deep enough I had to GENTLY pry the left side to "pop" the block from sticking to the receiver. Then had to go underneath and punch it out...finally. It was worth it. Saved a bunch of money. Learned a new skill. Was able to install my Chip McCormick trigger unit. Single pinned block. Pin is just above the safety. 
Sear block looking at it from the right side. 
Another view of the block. 
Inside after installing the McCormick trigger. 
|
AR Sponsor