Home Forums Reloading Big Game Rifles Flash hole diameters

This is kind of a long intro for my question, but a friend of mine uses the case length gauge/cutter thing from Lee Precision and I was amazed at how accurate they were. Even though I trim all of my cases on a regular trimmer, I thought these things were novel enough to buy a couple and try them out.

At a gun show a few months ago I picked up a few of these for next to nothing. I had a chance to use one of them this weekend and found that the pin on the "pilot" would not enter the flash hole. I contacted Lee today to see why this was. Lee Precision says that the componet industry switched to a smaller flash hole diameter about 10-12 years ago. The current Lee product uses a .062 diameter pin wheras the pins that I have measure at .078

The case gauges were "new-old-stock" I bought one in 6,5 x 54 Mannlicher-Schoenauer and another one in .308 Norma Mag. All of these were still in the original, blister carded, factory packaging.

So my question is why did the component mfgs. switch to a smaller diameter flash hole.

I haven't noticed any problems with my depriming pins and they all measure .070 except my one set of PPC dies and that is .060 but PPC cases did have a smaller flash hole. If your guide pins are actually .078 they may give you problems, shouldn't be difficult to reduce the diameter slightly as I doubt they are hardened steel.

One of the reasons the PPC is thought to be so inherently accurate is because of the smaller than standard flash hole size. I wasn't aware that other cases followed this trend???