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1/19/2011 3:28:21 AM EDT
On an m16, or any locking bolt auto, does the bolt fully lock during automatic?

I've never shot one, just curious.

Thanks

Posted Via AR15.Com Mobile
1/19/2011 5:29:21 PM EDT
[#1]
Yes, the auto sear's purpose is to delay the release of the hammer until the bolt is going to be closed and locked before the firing pin hits the primer.
2/6/2011 6:01:23 AM EDT
[#2]
Ok, so why does one have to 'time' a drop in sear but not a 3rd pin type sear?  I'm guessing manufacturing tolerances.

One more, should one chase the RDIAS route can a 3 shot burst be used, or do I need an RR for that?


Posted Via AR15.Com Mobile
2/6/2011 10:08:41 AM EDT
[#3]
Quoted:
Ok, so why does one have to 'time' a drop in sear but not a 3rd pin type sear?  I'm guessing manufacturing tolerances.

One more, should one chase the RDIAS route can a 3 shot burst be used, or do I need an RR for that?
Posted Via AR15.Com Mobile


Well first off with a RR the third hole is in a fixed location and can not be moved back or forth like a RDIAS can be.  If a M16 receiver is not drilled right the timing will be off and the receiver will have to be scraped.  However I believe most all transferables don't have this problem.

So when you use a RDIAS it may not be lined up front to back perfectly, so that is the reason why timing is needed for a RDIAS and not a M16 receiver.

For more on timing a RDIAS go here: http://www.quarterbore.com/nfa/dias.html

A 3 round burst or just burst because depending on the cam on the hammer it could vary from 1-3 or read it could be modified to do a 6 round burst.  Anyway yes they can be used with a RDIAS or RR.  There are 2 or 3 different Fire Control sets out there that have the 4 postion options safe/semi/burst/auto.  However the one requres no selector stops on the receiver, so it works well with those RR that don't have any or the RDIAS where you can grind them off since it's just a $100 part instead of a $8k+ part.
2/6/2011 11:33:10 AM EDT
[#4]
Quoted:
Quoted:
Ok, so why does one have to 'time' a drop in sear but not a 3rd pin type sear?  I'm guessing manufacturing tolerances.

One more, should one chase the RDIAS route can a 3 shot burst be used, or do I need an RR for that?
Posted Via AR15.Com Mobile


Well first off with a RR the third hole is in a fixed location and can not be moved back or forth like a RDIAS can be.  If a M16 receiver is not drilled right the timing will be off and the receiver will have to be scraped.  However I believe most all transferables don't have this problem.

So when you use a RDIAS it may not be lined up front to back perfectly, so that is the reason why timing is needed for a RDIAS and not a M16 receiver.

For more on timing a RDIAS go here: http://www.quarterbore.com/nfa/dias.html

A 3 round burst or just burst because depending on the cam on the hammer it could vary from 1-3 or read it could be modified to do a 6 round burst.  Anyway yes they can be used with a RDIAS or RR.  There are 2 or 3 different Fire Control sets out there that have the 4 postion options safe/semi/burst/auto.  However the one requres no selector stops on the receiver, so it works well with those RR that don't have any or the RDIAS where you can grind them off since it's just a $100 part instead of a $8k+ part.


My RR has no selector stops and I did have a Colt 4-Way FCG installed at one time. It worked flawlessly, but the burst mechanism makes the semi-auto trigger pull heavy and a 3rd burst is easy to do on auto using just trigger control, so I went back to the standard safe-sem-auto FCG.

Here is a pic of a Colt M4 Enhanced Carbine with the 4-Way parts.


2/6/2011 2:31:52 PM EDT
[#5]
Wow, thanks guys.



I'm kinda sorta doin research for a gentleman I work with, he's pursuing the Auto bug and thinks a RR is the way to go.  



The dude reloads something like 80 chamberings; knowing this I'm trying to steer him to an RDIAS and MGI lower.
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