223 action bolt nose height?

jzerfoss

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Jul 29, 2019
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I have a defiance deviant 223 and the measurement from the top of the bolt nose to the bolt face is .135" which is just enough to allow the case to be fully supported with maybe a few thousands unsupported. I recently got a Mack Bros Evo 2 in 223 and the bolt nose height is .150". I realize that the remington measurement is .150" it just seems like that maybe too much unsupported case with the 223.

Those of you that have other 223 actions what the measurement of the bolt nose to the bolt face on yours?
 
Most are .150 but the defiance is indeed closer to .135
Did it ever bother you seeing .040" +/- of unsupported case? With the 223 on average being .120" from the case head to base of the case body that leaves .030" with the .150" bolt nose. Plus .010" for clearance from the barrel and a chamfer. Just seems like a lot...
 
no, it doesnt bother me at all. case web end at somewhere around .190-.200 if I remember right
as long as the web is in the chamber, and someone doesnt put a gigantic chamfer on the chamber then everything will be fine.
Doesn't that .190" start from the case head not base of the case body? If it starts at the case head that would mean the case web would end where the chamber starts.
 
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lets say web ends at .200 from case head/bolt face (I think it may be a little more than that but for discussion's sake...)
counterbore is .150 deep
+ bolt nose clearance of .010
+ .015 for the chamfer on chamber edge
in the above scenario you would have .175 of unsupported case, meaning the web ends in the chamber and is therefore supported
 
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lets say web ends at .200 from case head/bolt face (I think it may be a little more than that but for discussion's sake...)
counterbore is .150 deep
+ bolt nose clearance of .010
+ .015 for the chamfer on chamber edge
in the above scenario you would have .175 of unsupported case, meaning the web ends in the chamber and is therefore supported
You're right. I mathed wrong lol