Hi. Would like to know how one measures amount of engagement between barrel and slide locking lugs in Browning/1911 style pistols?
Have read of using clay in the slide lugs and pressing in the barrel but seems this would tell you maximum possible engagement. How do you know the amount the lower lug/link system is allowing?
You can use plastigage. Can be found at most auto parts stores. Or you can soot it all up really good with candle smoke, re-assemble, lock up, dis- assemble and "eyeball" you engagement by the marks in the soot.
What matters is your particular combination of parts in their assembled operating state. I use a depth micrometer at the top front edge of the ejection port. You can also use the stem on the end of a dial caliper if you are careful with your technique. Measure once with the slide in battery. Then with the slide out of battery about 1/4 inch so that the top of the barrel is resting against the roof of the slide (not engaged). The difference is your actual engagement.
I use BBBBill's method. the trick is to be consistent on the placement of the tool, centered on the top of the slide. To make sure that the barrel is as high as the slide lug will allow it to go, use a makeshift shim between the breechface and the hood that's about .050 thick.