Tuesday, September 13, 2016

Correcting Excess Headspace in a Winchester 1890

Nope, it's not a shotgun and yes, I like .22s (good ones).  This Winchester 1890 had been restored (including a new barrel) and is cosmetically brilliant.  Apparently though, the breechface of the bolt had some pitting that was removed by milling the surface, thus creating an excess headspace condition.  The cases were rupturing when fired.  I would have welded the boltface and then remachined it.  Since I got the job after the fact, and refinishing the bolt wasn't an option, I took a different route.  I machined the boltface to accept a screwed-in insert.
The photos will explain.

The excess headspace condition, it's actually greater than shown here because I couldn't hold the bolt all the way to the rear (against the locking lugs) and also take the photo.

The breechface as it was,

 After machining for the new insert,

The blank insert installed,

 After machining and filing, the amount of excess clearance is evident by the amount that the insert stands above the boltface.

The finished job,

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