milsurpcollector Posted October 21, 2006 Report Share Posted October 21, 2006 I cut the chamber too deep in my milsurp replacement 03A3 barrel. After setting it back I am going to try again. I was using a depth micrometer with headspace gauges and comparing the results to the old barrel. But that caused me to ream too deep. I ended up having to requalify the barrel and recut the cone, twice (I screwed up the first time) So I need some advice before I ruin a $125 barrel Last resort I will screw it on the receiver and cut a little at a time. Link to comment Share on other sites More sharing options...
mad_jack Posted October 21, 2006 Report Share Posted October 21, 2006 The head space in measured from the bolt face to the top of the breech ( the front of the action where the barrel locks down on ) with you'r depth mic. take the measurment PLEASE NOTE THAT YOU NEED TO COMPLEATELY STRIP THE ACTION AND BOLT TO TAKE THIS MEASUREMENT, with the bolt in the locked position. This is the measurment you need to match with the ( GO ) head space guage in the chamber, measure from the back of the guage to the sholder on the barrel with you'r depth mic. Screw the barrel on the action tight and put the GO guage in the chamber and see if the bolt will close. It should close all the way with out force. Then replace the go guage with the NO GO guage and see how far the bolt closes before it stops. You want the bolt to start camming into the locked position BUT YOU DON'T WANT THE BOLT TO FULLY CLOSE. If the bolt doesn't start camming into closed position you can put an extention on the reamer and hand ream untill the bolt is where it needs to be. Note: when you'r hand reaming you need to go very slow and ONLY GO 1/4 TURNS AT A TIME. And always push patch to clear chips out of chamber every time you pull the reamer out. I always blow with air and use a patch one little bit of metal chaving will give you a fals reading on you'r headspace guages. Link to comment Share on other sites More sharing options...
milsurpcollector Posted October 21, 2006 Author Report Share Posted October 21, 2006 Thanks alot you are a lifesaver I knew I was doing something wrong I just didnt know what Link to comment Share on other sites More sharing options...
mad_jack Posted October 21, 2006 Report Share Posted October 21, 2006 NOTE: There is usually about .010" between the NO< and NOGO guages, on most callibers but they all very. Link to comment Share on other sites More sharing options...
Guest Guest Posted October 22, 2006 Report Share Posted October 22, 2006 Most run .006" between go and no go and another .004" to field for a total of .010" between go and field. Link to comment Share on other sites More sharing options...
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