I don't own a Franchi or a Stoeger ....but the few I've helped take apart to diagnose issues with at my club ....internally, while they look similar to the Benelli's, they don't look identical to me ....
.....and I only suspect -- but I haven't done a lot of thorough inspection or measuring of the parts between the various models ...but some of the internal parts don't appear to be made to the same specs as the Benelli parts....( especially on the Stoegers ).
I'll make the analogy to 1911 style handguns ...in theory they are a lot alike at least internally ....but who makes the parts, how they're fit ...makes a big difference / and it makes a big difference after they've each seen 10,000 rds ...or 25,000 or 50,000 ..../ but its hard to see with just the eyes.
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I'll wait for Slugo's range report ....lets hope it holds up and performs well !