AR-15....No Sear Block
I was wondering if someone would please clear this up for me. The early Colt AR-15's did not have a sear block. OKAY, so please help me understand what this means. I think I know, but I have not really had any real definitive explanation and would appreciate getting one. Can someone tell me? Thanks in advance
Fish Shudder at the sound of my Name!
Fish Shudder at the sound of my Name!
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The early Colt's had no sear block, enabling the addition of the parts necessary to render them select-fire-capable, a definite NoNo in Federal Legalese to those unwary enough to try it (who also lack the required license). Colt subsequently added the block to preclude this conversion taking place with their products. 0 -
Here's why I was wondering about this. Most Gun Makers that have Semi Auto Versions of Full Auto Weapons, manufacture in many differences which makes it a nearly impossible task to "convert" the semi's to full auto. It it isn't nearly impossible, it definitely is "cost prohibitive!" That being said, I sometimes help out a friend that owns a local Pawn Shop, (quite large volume store), and when I'm there, most always someone has "full auto" questions. Most of which I am able to simplify and brush off simply as "what you're asking is illegal." This works most of the time.
But, I was drawn into a conversation about the AR-15 regarding its absence of a "Sear Block." Because of this one Pre-Ban Gun without a sear block, I was informed it only took a couple of small parts to turn this gun into an "M-16." When I said I couldn't imagine that to be true, I started a conversation I wish I hadn't. It became plain I was being considered to be a "fool" more or less. Now I don't mind being that, if it makes a customer happy, but after it was over, I realized, "the guy was right!" I really couldn't even discuss the subject because of a lack of knowledge on this gun. For some reason, I just haven't made it a point to learn the "secrets" of the AR-15. Now that doesn't bother me much because I don't have a lot of interest in these guns anyway, but I would like to know enough to understand what I'm being told.
Can someone point out some information which will help me? I don't want to become an "expert" on converting one of these guns and don't really need any real deep details.....just an overall consensus that would allow me to talk...."slightly enlightened in the subject."
Thanks to those who help and to spclark for your reply.
Fish Shudder at the sound of my Name!0 -
RP, it was common in the 1970s and 1980s to install M16 parts in AR-15 rifles with the intent to make them fire full-auto. However, the M16 hammer, trigger, disconnector, selector and bolt carrier alone are not enough for reliable full-auto fire. (With just those parts, and no auto sear, the hammer will follow the bolt closed and usually will not have enough energy to fire the round if the round has hard rifle primers, although using soft pistol primers in the ammunition will usually result in full auto fire with just those parts.) The auto sear is needed to hold the hammer until the bolt is just closing, at which time the hammer is released by the bolt carrier striking the sear and the round is fired, repeating until the trigger is released.
While someone doing a registered conversion pre-1986 could drill the receiver and install an actual M16 auto sear, that required a hole in the receiver. Some ingenious person realized that the same effect of a permanent genuine M16 auto sear could be achieved by making a mounting block to hold a trip to perform the same function as the auto sear. The block was held by the rear upper receiver lug when the upper and lower were closed. The mounting block sat in the open area ahead of the selector and behind the trigger and hammer. That open area is where Colt put the block to prevent the use of auto sear blocks.
The auto sear blocks were reclassified as machine guns in 1981. There was one on eBay just recently, said to be pre-1981, so it is not classified as a machine gun. Of course, having the necessary parts now is forbidden even if not installed in an AR-15.
I cannot understand any "gun person" not being interested in this close relative of the longest-serving service rifle in U.S. history. The AR-15 and the semi-auto versions of the AK-47 are most often identified as "evil assault rifles" in the minds of the general public. Both are among the most important firearms designs in history.
RP, if this is not clear, please ask additional questions.
Edited by - JudgeColt on 11/05/2002 21:42:270 -
Paul, there are a few methods of converting an AR-15 to full automatic and I won't go into the actual conversion details. This would no longer be legal since the 1986 ban on manufacture of machineguns for transfer to individuals. Here are three methods that have been used: The first is to actually drill the rear of the reciever to accept the M16 auto sear. The presence of this hole in an AR-15 type rifle makes in a machinegun PERIOD and subject to registration. The block prevents the hole being drilled without major work to the receiver. There used to be companies that sold drilling templates for this purpose but they seem to have vanished.
The next method would be the use of a "drop in auto sear". This little goodie preforms the work of the real auto sear and drops into the space which the block fills. You'd have to remove the block and install the correct full auto componets to make the rifle select fire. Drop in auto sears are now considered to be machinegun conversions and must have been registered prior to 1986. Drop ins manufactureed prior to 1981 are exempt from the machinegun registration...as long as you don't own an AR-15 type rifle! If you have the drop in and an AR-15 you have a machinegun. As mentioned, the block fills the space where the drop in would fit.
The final method I'll mention is the "lighting link" conversion. This is a crazy little unit that is basically two pieces of metal and fits into the rifle and more or less tricks the gun into thinking that an auto sear is present. It provides only automatic fire and semi-auto is not possible with this device installed. People used to make these out of metal about the thickness of an old hack saw blade. Possession of a link and an AR is considered possession of a machinegun. The block in the receiver prevents the use of such a link device.
There are other methods as well, but these are the most popular...and all are now prohibited. Do I know the details of how this is done? Yes. Will I provide more information in an open forum? NOT A CHANCE!
You just never know who reads these posts.
I see JudgeColt beat me by about 40 seconds!
Mark T. Christian
Edited by - mark christian on 11/05/2002 21:43:310 -
Thank you, Judge Colt, and Mark! This is the info I was needing. It is as I suspected. Just because it doesn't have a sear block could mean or not mean, it is easy to convert, depending on what you wanted to do to make it so. In looking at some of the other common full autos that have semi auto counterparts, it seems the Colt AR-15 is made much the same. With the additional provisions of the rules and regs. regarding these, it becomes obvious that it really doesn't matter whether or not it has a sear block.
It's just a matter of how you want to go about putting your own hind end into whatever color "sling" you would feel best in....Hahahaha! Thanks again, for the info. Now I will know what they're talking about should the subject come up again.
By the way, Judge, I do know the "timeline" of the M-16's and the AR's and what they have done, what they are, and pretty much why......just didn't get into the mechanics of the guns. Colt always seems to have made the exact "tool" to do the job it was designed for.....and these were no exception. Thanks again!
Fish Shudder at the sound of my Name!0 -
To me, the main value of an unblocked AR-15 is that it is different from a blocked rifle. That small difference is what adds the collector value to the unblocked rifle. It has nothing to do with converting it to full auto fire. The fact that Colt responded to political pressure when putting in the block also makes the unblocked guns more valuable to those of us who think the cosmetic assault weapons law is very offensive.
RP, I am not sure I understand all your last response. I think any unblocked AR-15 would be require the same modifications to convert. All unblocked AR-15 rifles would be equally easy to convert. Some would not be easier than others. However, since 1986, no legal conversions can be made, unless (I think) a registered auto sear is used.0 -
Just a follow up question, I notice a lot of people building up their own AR's using stripped lower receivers from bushmaster, DPMS, et. al. Do these stripped lowers come with blocks? 0 -
Judge Colt....what you are saying is what I was trying to say. I was told the other day that the "unblocked gun only needed a few small parts changed to make it into an M-16," by a person who wanted very much to be recognized as an authority on the subject. I was not well enough versed in the subject to object or concur. I had to be "baffled with his brilliance" and to try to learn something.
Most of the questions I get when helping my friend at the Pawn Shop usually center around the Tec 9's, UZI's, AR-15's and AK's, etc., and eventually lead to attempting to discuss the ease of conversion to full auto. Not sure why they have this mistique but they seem to. I can generally keep from being engaged in such a discussion by answering, "a license from the BATF" when asked "What's it take to.....?"
I just realized that I was pretty dumb about the internal mechanism of the AR-15's and also realized I have very little literature on them. That was the reasoning behind my questions.
I also would agree that a gun without the sear block would be of more collector interest because of that fact. Yes, Political Correctness is very interesting! But, that is a topic for another discussion. Thanks again for your help!
Fish Shudder at the sound of my Name!0 -
RP, glad to help. There used to be a series of books showing how to convert various semi-automatics to full auto. Reviewing those books might help you to understand the various mechanisms.
drobs, I am not sure about how all the various current clones are configured. I seem to recall that one clone brand had the lower receiver machined differently so that a drop-in auto sear would not fit, but it did not have an actual block like the Colts. However, the effect was the same. I do not recall which clone it was that was machined that way, but probably have it recorded somewhere.0 -
Figured so. Thanks Judge!
It's getting so that decent people can't walk on the streets without SCUM like you stepping on all that's decent in this world.0
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