seems like you could test the barrel/receiver to toggle asy with go/no-go gauges
but beware that the excess looseness / wear in some toggles asy / connecting pins may create some misleading variation in the correct headspace measurement
like :
http://www.brownells.com/gunsmith-to...prod25181.aspx
note the breechblock damage on sample at the top view picture - a 30 cal example! ( slide magnify to max )
http://www.simpsonltd.com/product_in...ducts_id=31706
happy trails
Bill