Compare to unfired/new brass. If the base is growing .003" or more it will probably stick in the chamber. Being hard to load or unload.

If I'm understanding you here is the results from Factory round and fired round.

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Name:	Factory.jpg 
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ID:	6166

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Name:	Fired.jpg 
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Size:	150.9 KB 
ID:	6167

Fired = .05550
Factory = 0.5499
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Diff of .0051