T. O'Heir,
That may be, but they can still make tight chambers that may increase pressure. Example: I have a Ruger Redhawk that has 5 chambers that shoot into about 5/8" C.T.C. at 50 yards, and the sixth chamber opens that up about 1 5/8". A friend of mine was so impressed by it that he bought a copy. His wouldn't stay on a dinner plate at that distance. All chambers all over the map. So we sent the gun back to Ruger with a note explaining how well my copy shot compared to his. His came back 5 weeks later with a note saying the cylinder (chambers) had been reamed. The gun then shot well. So, despite their concerns, we know Ruger can still turn out a tight chamber when its reamers get worn, or there would have been nothing for them to ream in my friend's cylinder. Those tight chambers, in turn, affect pressure.
Jim8115,
Tight extraction is a classic pressure sign for revolvers. Steel can stretch further than brass can and still return to shape. Steel makes a better spring for this reason. When case extraction becomes sticky, it generally means the steel at the inside diameter of the chamber is expanding beyond the brass's spring limit (its yield point). As a result, the steel snaps back to shape over top of the now-slightly-oversize brass, trapping it and causing the difficult extraction.
If you get sticky extraction from your handloads and not from commercial loads, it's a pretty definite sign of excess pressure. At the least, your loads are making higher pressure than the commercial loads are. Some guns will take that, especially if the cylinder walls at the thinnest part of the chamber, the outside edge, are thicker than the 101's. That's something you can measure with a caliper well enough for comparison purposes. In the meanwhile, sticky extraction in a revolver means knock the loads for this gun down 5% from the level at which sticking begins.
So, why are your loads warmer: You used a different lot of powder than the manual did. You used a different primer. You used different, possibly thinner brass. You used a different bullet that is either harder (thicker jacket) or that seats more deeply when the crimp cannelure is at the case mouth than did the bullet the load data was developed with. All these things can cause some differences in pressure individually, and in combination they can add up. This is why published load data is more like a suggestion than a rule, especially when you near maximum.
You could get the lighter gun's chambers reamed. You could also have bore that's a little tight or constricted where it screws into the frame. If you can measure that the chambers are tight, Ruger might be willing to ream them, but you need to complain about accuracy, and not handload problems if you do. No gun maker likes to encourage or make accommodations for hand loads for liability reasons.
