Krag Collectors Association Forum Archive
Firearms >> U.S. Military Krags >> More Bolt Trivia
http://www.kragcollectorsassociation.org/cgi-bin/yabb2/YaBB.pl?num=1555357891

Message started by butlersrangers on Apr 15th, 2019 at 7:51pm

Title: Re: More Bolt Trivia
Post by FredC on Apr 16th, 2019 at 10:19pm
I know where I had seen the star now it was on your hand written list. Probably means the same thing as on a barrel, all dimensions checked and near the mean. Maybe like a first article inspection after tools are changed or the whole set up is refreshed.

On these drop indicators the gauge tolerance should be 1/2 the smallest division. The smallest division on this one is .0005 inches but I have never verified that it is really that accurate. With dial calipers the same rule applies about 1/2 a division, with digital you can not split the last division so I do not know what the rule is there. In a production shop we never trusted calipers for anything closer than a Plus or minus .005 tolerance. That was a long time ago before good digital calipers became available.  I still follow the old rule in my shop as I can find a better way for production measuring with indicators or specialized mikes. Mainly use calipers for quick reference.

On the depth of the recess I would not have held that as close if I was making them. Close tolerance is always costly only do it when necessary and that is the lug to the recess. Measuring with calipers is a little iffy for precision. I would be more comfortable with a depth mike, but one place I worked at called depth mikes Volkswagon bumper jacks and despised them. We used them in production shops and were comfortable holding .001 with them.

What does NOS stand for exactly, I am taking that it means no visible wear.

I too would like to see a bunch of new ones measured. I am trying to think of a safe way to check about 10 from Dave at Grandpas or making a quick and dirty gauge that would be repeatable and could be easily shipped to you and maybe Dave to check a bunch of bolts.

Krag Collectors Association Forum Archive » Powered by YaBB 2.6.0!
YaBB Forum Software © 2000-2024. All Rights Reserved.