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11/15/2011 4:55:34 PM EDT
I have a Green label Colt carbine and the bayonette lug has been removed. I'd like replace it with a Colt sight that has the bayonette lug intact. I have the pencil barrel carbine. Thanks for pointing me in the right direction!
Nick
11/15/2011 4:59:55 PM EDT
[#1]
Try Apex.

https://www.apexgunparts.com/product_info.php/cPath/49/products_id/1378
11/15/2011 5:07:27 PM EDT
[#2]
Your front sight base and barrel were drilled together as a unit, I don't think you can do this unless you go with a clamp on or set screw style sight base.
11/15/2011 5:36:39 PM EDT
[#3]
Im not understanding what you mean. Are you saying the barrel and the sight are machined to fit and there is no standard spec so these parts can be interchanged?
11/15/2011 5:47:31 PM EDT
[#4]
The sight base is installed on the barrel and then it is drilled to mate it to the barrel.

So basically you are stuck with that sight base because I don't know any place that will fit a new sight base to a barrel that has already been drilled.

That's why I mentioned clamp on and set screw types.
11/15/2011 5:48:17 PM EDT
[#5]
Quoted:
Im not understanding what you mean. Are you saying the barrel and the sight are machined to fit and there is no standard spec so these parts can be interchanged?


Yes. They are drilled to each other and do not interchange from barrel to barrel. I'm sure someone like ADCO could do it but it may be a bigger pain than it's worth.

11/15/2011 5:59:23 PM EDT
[#6]
And if they could, I wouldn't want to pay the bill !
11/15/2011 6:38:43 PM EDT
[#7]
So by "drilled to each other" are you meaning the barrel outer dimension and the sight inner dimension are machined to fit one another and then the 2 pins are installed? Not that i dont believe this, its just that I would think these dimensions would not be that different from Colt.
What areas does the term Mil Spec apply if an Armorer cant swap these parts at random between barrels? Also, why are there sights and barrels for sale... Again not being a jerk just find this disappointing.
Nick
11/15/2011 6:43:47 PM EDT
[#8]
No.

Look at your sight base and notice the pins. The pins actually sit in notches that have been drilled into the barrel during the sight base installation process.

Once a barrel has these two notches cut into it, you can't take a brand new sight base and match it up.
11/15/2011 7:50:39 PM EDT
[#9]
Drill/tap the replacement FSB and use set screws and/or Loctite 609 sleeve retainer.


11/15/2011 8:07:19 PM EDT
[#10]
ADCO had been replacing FSB for a very long time, I've seen their services list that they could supply the 0.750" ID FSB but don't see any 0.625" ID for the lightweight barrels.

Maybe post this question on ADCO's industry forum and see what they say.

Another option but probably more expensive is to get an estimate from SAW (Specialized Armament Warehouse).


http://www.adcofirearms.com/shopservices/shop_.cfm?code=5


11/15/2011 8:18:35 PM EDT
[#11]
Those bayo lugs get in the way.
11/16/2011 1:08:44 PM EDT
[#12]
Okay, now I see where you are talking about the "drilling" of the barrel and the FSB!!! Thank you for your patience in giving me this education.
Thank you to all that have responded.
Nick Nichols
11/16/2011 1:15:04 PM EDT
[#13]
I've had ADCO do it, but I supplied a new undrilled FSB, they were able to match it to the holes in the barrel. I believe Bigbore said the old drilled FSB was basically useless.
11/16/2011 5:26:55 PM EDT
[#14]
Quoted:
I've had ADCO do it, but I supplied a new undrilled FSB, they were able to match it to the holes in the barrel. I believe Bigbore said the old drilled FSB was basically useless.

I don't get it.

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