Two part comparator

[ovenpaa]

I have wanted to build a new simplified yet accurate comparator for a while and tonight I took some time out to turn the sketch on the white board into something tangible plus I do not have one of my three section comparators for the 6,5X284. The new design had to offer the same alignment features as before so I knew the upper and lower tools were always perfectly in line, plus still give the accuracy the three section system did and here it is.



The upper and lower interlock via registers to ensure they are perfectly aligned and they attach to the callipers with thumbs screws, the slot is sized to be a snug fit on callipers so they do not move around and I offset the grooves so they can only go onto the callipers in one position, I also add a stainless M5 grub screw that can be tightened to fine tune the comparator if needed, I added this feature after coming across some callipers that the jaws were slightly sprung on, they closed perfectly and zeroed but were slightly bowed in the long axis. The grub screw seems to help however a gentle twist of the comparator also does the job.

Here is the comparator in position, nicely aligned and locked in place.



Finally the comparator in operation. I find these types of comparators (two and three section) so much more accurate than the other offerings currently on the market. No doubt someone will copy the idea at some point but until then…



Anyway, I am very pleased with the result and look forward to measuring some loaded rounds. The cartridge in the comparator is actually a dummy 6,5SE that was sitting on the bench and was grabbed to demonstrate the process.