What is the proper diameter of a .45 chamber? Both go and no-go gauges fit with clearance, but fit correctly. But a fired brass is snug. The brass is .476+, the chamber about .473. The reason I ask is I have a number of shells with blow back or powder residue about half way down the case. It is a used barrel but the lugs are good and the rifling sharp. One other barrel that is handy measures about the same.
You should be able find chamber specs from SAAMI website. Were those rounds you fired handloads? Powder residue is usually indication of low chamber pressure; the load is on the light side. -TL
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Most of my reloads are toward the low side, but I think these were factory loads. All of my 1911’s are older so I don’t like to punish them, but I like to shoot them.
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Having soot on your brass is not unusual. Low pressure rounds do not swell the brass case enough completely seal the chamber and some gasses flow back around the case. DC
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Powder down the side of the case is not a real issue. Never use a fired case to check chambers….even a case fired in the same gun as it will never insert exactly the same as it came out and remember no chamber is perfectly round so you will simply get misreads on whatever you are checking. If you are checking extractors or something of that nature a fired case is fine but that has nothing to do with the chamber dimensions. Ken
