I never got back over to where my calipers were, but just remembered I had a box of ammo with me. I grabbed the tape measure and found out that my calipers apparently are not reading correctly! I specifically remember the other day a loaded factory RST hull was 2.7” and my chambers were 2.775”. Well…. I just put a factory loaded hull up against the actual tape measure and it’s a hair under 2 1/2 inches. So the extra .075”” I measured in my chambers would basically be 2 1/2 inches. Needless to say that made my head spin when I just measured one a few minutes ago with a tape measure. I’ll remeasure the chambers tomorrow to verify. So my cheap digital calipers were reading incorrectly…my fault for not verifying measuring with a second source other than those calipers. I will post back what I found after I measure my chambers again with something else besides the faulty calipers. Looks like the RST hulls that I thought were too long look like they are right on the money are going to be 2 7/8 inch total length unfolded… or pretty darn close to it. So…It was the calipers not reading correctly that was throwing me off. I’ll be curious to find out if something weird happened and I didn’t zero them at some point in both measurements of ammo and calipers were off or something happened after I measured the chambers and didn’t raise zero for the ammo. Either way, it sounds like I have a 2 1/2 chambered 10 gauge and the 65 number is correct for millimeters after all.
