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Posted: 1/31/2006 7:10:25 AM EDT
Check out the bolt on left, the bearing surface where the bolt contacts the inside of the carrier.  This band is interrupted.  See it, bizarre:

ar15.com/forums/topic.html?b=7&f=119&t=322979

Link Posted: 1/31/2006 7:28:20 AM EDT
[#1]
Very interesting......
Link Posted: 1/31/2006 10:40:52 AM EDT
[#2]

Quoted:
Check out the bolt on left, the bearing surface where the bolt contacts the inside of the carrier.  This band is interrupted.  See it, bizarre:

ar15.com/forums/topic.html?b=7&f=119&t=322979



Sand cuts?
Link Posted: 1/31/2006 10:59:05 AM EDT
[#3]
Sand cuts?  You know that is the first thing I thought, reminds me of a UK L1A1 bolt barrier.
Link Posted: 1/31/2006 11:05:06 AM EDT
[#4]
tag!
Link Posted: 1/31/2006 11:29:03 AM EDT
[#5]
I have nothing to add, but that is different and interesting.
Sand cuts are the only thing that comes to mind here, also.
Link Posted: 1/31/2006 11:44:47 AM EDT
[#6]
intresting indeed.

saw that thread the other day but didnt pay close attention to notice that.
Link Posted: 1/31/2006 11:57:30 AM EDT
[#7]
Since you're on the topic of odd colt stuff.  How about a new selector.

ar15.com/forums/topic.html?b=2&f=29&t=149289
Link Posted: 1/31/2006 12:07:42 PM EDT
[#8]

Quoted:
Since you're on the topic of odd colt stuff.  How about a new selector.

ar15.com/forums/topic.html?b=2&f=29&t=149289



How about them apples?  I don't like it, change is bad.
Link Posted: 1/31/2006 1:33:15 PM EDT
[#9]

Quoted:
Since you're on the topic of odd colt stuff.  How about a new selector.

ar15.com/forums/topic.html?b=2&f=29&t=149289



The selector's not the issue for me.  I'm astonished that Colt is STILL milling off the selector stop tabs on the semi autos; just like on my SP1.

Well, at least they're not drilling an 8mm hole at the front end any more
Link Posted: 1/31/2006 2:56:37 PM EDT
[#10]

Quoted:

Quoted:
Since you're on the topic of odd colt stuff.  How about a new selector.

ar15.com/forums/topic.html?b=2&f=29&t=149289



The selector's not the issue for me.  I'm astonished that Colt is STILL milling off the selector stop tabs on the semi autos; just like on my SP1.

Well, at least they're not drilling an 8mm hole at the front end any more



I don't get that at all.

I really prefer the stop tabs on lowers, and think it adds something to them.

WTH is the difference? I didn't realize Colt made that a conscious decision. Oh well.

And that bolt on the left is most interesting. I think I'll subscribe to this one to see if an explanation comes along
Link Posted: 1/31/2006 3:49:48 PM EDT
[#11]
Link Posted: 1/31/2006 3:54:42 PM EDT
[#12]

Quoted:
Looks like they ran the machine out when cutting the lugs.  I vote manufacturing artifact.



A mistake, say it ain't so!
Link Posted: 1/31/2006 4:17:15 PM EDT
[#13]
I have a current production bolt with those cuts.
Link Posted: 1/31/2006 4:20:37 PM EDT
[#14]

Quoted:
I have a current production bolt with those cuts.



What make of bolt?  Now that would be real weird, for an odd variation like that to pop up again years later.  Notice his bolts have the M & P ran together, as in old stuff.  You sure you are looking at the same thing?
Link Posted: 1/31/2006 4:23:08 PM EDT
[#15]

Quoted:

Quoted:
I have a current production bolt with those cuts.



What make of bolt?  Now that would be real weird, for an odd variation like that to pop up again years later.  Notice his bolts have the M & P ran together, as in old stuff.  You sure you are looking at the same thing?



It's a Colt with a seperated M and P.  There are three breaks in the band on mine.  I'll try and bring the digital camera home from work tomorrow.
Link Posted: 1/31/2006 4:30:46 PM EDT
[#16]
Link Posted: 1/31/2006 5:35:51 PM EDT
[#17]

Quoted:

Quoted:

Quoted:
I have a current production bolt with those cuts.



What make of bolt?  Now that would be real weird, for an odd variation like that to pop up again years later.  Notice his bolts have the M & P ran together, as in old stuff.  You sure you are looking at the same thing?



It's a Colt with a seperated M and P.  There are three breaks in the band on mine.  I'll try and bring the digital camera home from work tomorrow.




Quoted:
I have a bolt like this somewhere.



How about that, new to me.
Link Posted: 1/31/2006 6:55:07 PM EDT
[#18]
tag
Link Posted: 1/31/2006 7:39:26 PM EDT
[#19]
yeah, looks like the lug cuts could have gone too far.  wierd.

Link Posted: 1/31/2006 8:02:02 PM EDT
[#20]
Don't think it is uncommon, I have several Colt bolts with these cuts.
Link Posted: 2/1/2006 6:50:19 AM EDT
[#21]
Link Posted: 2/1/2006 7:18:25 AM EDT
[#22]

Quoted:
Thats where the lugs were broached. The grooves are usually not the same depth all the way around. You see it alot more on the Vietnam era bolts. Some have it, some don't.

Brett



Broaching is done to an I.D., like the lugs on a barrel extension.  The lugs on a bolt are most likely hobbed. Hobbing would be the fastest way to machine the lugs, from a production standpoint.  It looks like the pictured bolt was hobbed too far. Doesn't mean it is bad, or out of spec. though.
Link Posted: 2/1/2006 7:33:59 AM EDT
[#23]
We are talking about two different things here.

As wpnsman explained to me the 45 degree cuts in the bolt head behind the lugs are a result of 45 degree bevel cut on the side of the lugs.  We discussed this issue in great detail here:

ar15.com/forums/topic.html?b=3&f=118&t=213973&page=4

This cut was done on all the bolts I have or have seen from at least 1962 till at least the end of M16A1 production.  Since that time it is rare to see them.  I only have one later one with them, my 1995 RO921 bolt has them, but much harder to see then the old ones.  

Have seen a couple of newer bolts with the cuts pop up in the last two weeks, Colt's must have made another batch recently?  Here is an example:

gunbroker.com/Auction/ViewItem.asp?Item=42575351

Far as the "interrupted band" goes, I sent wpnsman a link to that one.  He explained that "I've seen bolts like this occassionaly."  He goes along with the theory that they are a "manufacturing anomaly" or a "ooops".  I agree.
Link Posted: 2/1/2006 8:45:58 AM EDT
[#24]
So it's an anomaly since it's Colt.  Would it be a mistake if it were RRA?  I just noticed your sig and figured I'd ask.  
Link Posted: 2/1/2006 8:57:35 AM EDT
[#25]

Quoted:
So it's an anomaly since it's Colt.  Would it be a mistake if it were RRA?  I just noticed your sig and figured I'd ask.  



Go back and read the thread, you will notice I used the term "mistake", and also quoted "oops".  The term "anomaly" was a direct quote of WpnsMan.

Again, Colt's makes mistakes, some of which I have detailed complete with visual aids and statistics, it is IZHMASH that does no wrong.

BTW, never seen a RRA M16A1 bolt that was less then perfect, and bet I never will.
Link Posted: 2/1/2006 8:59:53 AM EDT
[#26]

I vote sand/debris/fouling cuts.  And I want some!
Link Posted: 2/1/2006 9:52:26 AM EDT
[#27]
That bolt was made on a Friday
Link Posted: 2/1/2006 12:11:34 PM EDT
[#28]
I was just teasing.  Plus, I was obviously trying to bring up a point about some people's perception...
Link Posted: 2/1/2006 12:24:33 PM EDT
[#29]

Quoted:
I was just teasing.  Plus, I was obviously trying to bring up a point about some people's perception...



BIG 10-4 there.
Link Posted: 2/1/2006 12:47:08 PM EDT
[#30]
I think that I have one or two like that.
Link Posted: 2/1/2006 12:56:58 PM EDT
[#31]

Quoted:
So it's an anomaly since it's Colt.  Would it be a mistake if it were RRA?  I just noticed your sig and figured I'd ask.  



I know you're joking, but if it were unintended COLT would have rejected the bolts faster than you could say "87"!!!
Link Posted: 2/1/2006 3:36:06 PM EDT
[#32]
I'm going to look through my stuff and see if I can find one like that.


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