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Posted: 4/13/2003 3:46:58 AM EDT
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I am having a headspacing problem and looking for others input. I have a original Colt XM-177 barrel that a G.I. mil-spec bolt and carrier will close on a Forester "No-Go" gauge, but will not close on the "Field" gauge. I installed a brand new G.I. mil-spec barrel on the upper receiver, and the bolt/carrier will still close on the no-go gauge. I tried a Colt bolt and carrier from one of my other rifles and it would not close on the no-go gauge. Does this sound like I have a bolt/carrier that is out of spec? Any input is appreciated. |
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Man0ica, I am impressed; someone how actual checks the headspace before firing the weapon. You are correct that the bolt is out of spec for the barrel. You will not have to change out the carrier, but you will need to get a new bolt to match the barrel. Since the barrel is used, my guess is that there is chamber or back faces of barrel extension wear. Depending on how close you live to a supplier, I would just take the gauges down with the stripped barrel and start checking bolts in the barrel. Worst case, just send the barrel off and have a bolt match to the barrel. Also, very sweet deal on scoring the shorter XM-177 barrel. Did the barrel come with the moderator, or are you planning on using a Suppressor to create the backpressure for the smaller gas port on the 10" barrel. The E1 had an 11.5" barrel and solved some of the backpressure problems. |
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Actually it is an 11.5" E1 barrel, (I picked it up new from a guy who thought it was too short for hunting-go figure) and has been installed on one of my receivers for quite a while, and has functioned flawlessly. It headspaced fine then, and still does with a Colt bolt and carrier. When I used the G.I. "mil-spec" bolt (that I had purchased from Fulton Armory) to check a brand new G.I. barrel I recently installed on another receiver, it closed on the no-go gauge. I then tried the G.I. bolt/carrier on the rifle with the 11.5" barrel, it closed on the no-go gauge also. Like I said before, when the Colt bolt/carrier is installed, it will not close on the no-go gauge. I will try and find a new bolt to see if this clears up this problem. I just read in the "Troubleshooting Checklist" at the beginning of this section, that the Forster no-go gauges (.223) are slightly shorter than the 5.56 G.I. no-go gauges. Maybe that is what my problem is, since this bolt closes on a no-go gauge with a brand new barrel. I really appreciate the feedback from you guys, thanks for the help. |
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The Go and No-Go Gauges are for new build of the gun. The field gauge is intended to check if headspace is too far gone on a used gun. If you are handloading, just adjust your sizer to size the cases less. If you are shooting factory ammo, and it gets to the point of swallowing a Field Gauge, then you should DEFINITELY CONSIDER A LONGER BOLT OR A NEW BARREL. The real limit occurs when you either start failing cases or can not get them to fire because the firing pin's reach is not long enough. |
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