Unfired colt government carbine preban with sear block

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Just bought a 100% complete colt government carbine, unfired with green label box. The problem is it has a sear block. The sesr block is a single pin from right side of the receiver. It has all the preban features with a small pivot pin. Should I leave it alone or remove sear block. Thank you in advance.
 
The Colt guns with the "sear block" were made at a time when the aftermarket (non-Colt) competition was just getting started. I remember thinking, at the time, "why get a Colt when something else, closer to the military prototype, was available?" Colt's decision to treat its customers as potential criminals was a serious marketing mistake. I haven't bought any Colt AR's since then (and I have a pretty big collection of AR's). Any gun with a "sear block" would certainly be a non-starter for me.
 
The Colt guns with the "sear block" were made at a time when the aftermarket (non-Colt) competition was just getting started. I remember thinking, at the time, "why get a Colt when something else, closer to the military prototype, was available?" Colt's decision to treat its customers as potential criminals was a serious marketing mistake. I haven't bought any Colt AR's since then (and I have a pretty big collection of AR's). Any gun with a "sear block" would certainly be a non-starter for me.

I agree Colt did, still does, treat its civilian customers like criminals but you do realize that most AR manufactures simply make the sear block part of the lower. Even if you drilled the .125 hole in the correct location with nearly all lowers you would still need to remove material internally to fit an auto sear.
 
Most certainly leave it.
They were to impede both a retrofit of a GI trigger/sear combo and the old *drop-in* sears and affect your operation of the carbine, not a whit.
Since you have all the *as Shipped* items, leave the carbine too; As Shipped to include no upgrades that you can not back out of.

Todd.
 
I agree Colt did, still does, treat its civilian customers like criminals but you do realize that most AR manufactures simply make the sear block part of the lower. Even if you drilled the .125 hole in the correct location with nearly all lowers you would still need to remove material internally to fit an auto sear.
The "sear block" goes well beyond the traditional internal machining of the semiautomatic lowers. I have a couple of early SP1's (1967-68), without the "sear block," and those would certainly need to be opened up inside for a GI auto sear to fit. What the "sear block" (made of hardened steel) does is to make the machining operation more difficult, unless it is removed. But drilling out the blind pin that holds the "sear block" in place is not too much of a problem.

IMO, a Colt gun with the "sear block" removed is ugly as sin, even if an attempt is made to fill that big ole hole where the pin was.

The whole idea of illegally converting a semiautomatic gun to full automatic is silly. What you end up with, besides a felony, is a gun that isn't much more effective than it was originally. It may be fun to do "mag dumps," but in the real world all this does is waste ammunition.

Prior to 1986, it was possible to do this legally using ATF Form 1. I made the decision, back then, not to do that. (Admittedly, I did have some factory FA's. That's how I learned that having the FA capability was not such a big deal.)
 
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Thanks guys for all your input. Bought this to shoot so I'm gonna shoot her lightly. Being from Massachusetts I had to pay dearly for this gun. Was worried that it might be a bad one because of the sear block.
 
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Thanks guys for all your input. Bought this to shoot so I'm gonna shoot her lightly. Being from Massachusetts I had to pay dearly for this gun. Was worried that it might be a bad one because of the sear block.
Shooting it sounds like a fine idea. To have shot it and care for it well will have less long-term effect than will losing the box & paperwork or permanently modifying in any way.

Too, should you ever have anyone else work on it - watch for them taking out fine old Colt's parts and conning you into some re-pro crap. Don't mean to tweak you if you are capable of any possible - though unlikely - work it might need in the future. I've sadly seen lots of valuable components go into unscrupulous parties parts supply with guns as with cars or motorcycles.

Todd.
 
Shooting it sounds like a fine idea. To have shot it and care for it well will have less long-term effect than will losing the box & paperwork or permanently modifying in any way.

Too, should you ever have anyone else work on it - watch for them taking out fine old Colt's parts and conning you into some re-pro crap. Don't mean to tweak you if you are capable of any possible - though unlikely - work it might need in the future. I've sadly seen lots of valuable components go into unscrupulous parties parts supply with guns as with cars or motorcycles.

Todd.
A question as I am not that familiar with the MA rules: can you swap other uppers on the pre-ban lower, or does that change its status?
 
It is most likely that a Milspec upper will not fit the Colt.
The upper will be fine, he'll need to maintain the original carrier or make sure that the one accompanying the next upper has a fully under-cut (semi-auto only) carrier to clear the sear-block's vertical protrusion. This is there to ensure that an M-16 carrier will never fit.

Todd.
 
The upper will be fine, he'll need to maintain the original carrier or make sure that the one accompanying the next upper has a fully under-cut (semi-auto only) carrier to clear the sear-block's vertical protrusion. This is there to ensure that an M-16 carrier will never fit.

Todd.
But if the pivot pin is not Milspec like on most of the early Colts it will need an offset bushing.
Most people don’t know that Colt had two different lines of ARs. One for the military and one for the civilian market.
The civilian ARs were not made with the same parts.
 
I SBRd mine, and I ended up removing it because a primer somehow managed to get stuck under there and jam up the safety. It does leave a big ugly hole.

The front takedown pin is a double headed screw and there’s no detent. In fact the hole isn’t even drilled to install a detent pin and spring. Stupid.
 
Well most aftermarket triggers will not fit and very few bolt carriers will either. I have one like yours and kept it stock. Itool it to training seminars in early 90 s with a Swan goose neck and an M2 Aimpoint when they became available. It was not that reliable in 3 day classes with up to 1000 round counts. It was traced eventually to a defective carrier. I turned gun back to stock and put it away for future. I have a Flat top hbar from same era, cut out the seat block and run giessel trigger and a BCM bolt carrier ect.and it is 100 percent. I have a very old 1970 sp1 CAR that still runs !
 
The front takedown pin is a double headed screw and there’s no detent. In fact the hole isn’t even drilled to install a detent pin and spring. Stupid.

You know what... I've never checked my big pin H-bar for that. It has the double-screw front pin, but I never looked to see if it had a void for the detent pin...
 
There were some transitional rifles that made it out with a mix of features but one generally can expect different takedown hole sizes, machined off BCG, larger pins for the trigger and hammer, that make them less than ideal for swapping stuff around, if you are going to leave it stock, just shoot it.

If you paid a premium for it, I would keep it unfired and see if you can find someone else that would and start your search for what you want again.
 
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