Forster Datum Dial

[JeffreyDeGraff]

Ive never had a headspace comparator before, so this has been very eye opening for me.

WW 30-06 range brass I got from Wes, varied up to .015”

Hornady 6mm Remington brass that I fire formed to 257 Roberts, is .005” shorter than FC 257 Roberts brass fired from the same gun.

S&B 7x57 brass loaded with powder puff loads were .010” shorter than same brass fired at standard pressures.

New Hornady and Nosler 280 Ackley brass were .002” longer than fireformed RP 280 brass, but twice fired RP brass was .005” longer that the Hornady and Nosler.

I haven’t used the bullet comparator yet, but I’ve been using the Sinclair hex bullet comparator for years.


JTD

[Flyeralan]

Ive never had a headspace comparator before, so this has been very eye opening for me.

WW 30-06 range brass I got from Wes, varied up to .015”

Hornady 6mm Remington brass that I fire formed to 257 Roberts, is .005” shorter than FC 257 Roberts brass fired from the same gun.

S&B 7x57 brass loaded with powder puff loads were .010” shorter than same brass fired at standard pressures.

New Hornady and Nosler 280 Ackley brass were .002” longer than fireformed RP 280 brass, but twice fired RP brass was .005” longer that the Hornady and Nosler.

I haven’t used the bullet comparator yet, but I’ve been using the Sinclair hex bullet comparator for years.


JTD

Jeffery, the one thing I know about forming 6mm and 7mm TCU brass is that I have to leave them long for fire-forming or they will end up short. Kinda makes sense when you think about it. (Thinking specifically about the Roberts forming) I am very curious about the 7X57 powder puff loads ending up shorter? That just doesn't compute, guess I"ve still got plenty to learn. Thanks for sharing, this is very interesting.