Newb question

[Charlie-NY]

Been reloading for over 40yrs but I'm new to the world of 6mmBR. I had a new Krieger bbl put on a Rem 40X action that was shot extensively in 22-243AI.

I've got new Lapua brass, Berger 105Hybrid bullets and CCI 450 primers. While I'm waiting for some dies I figured I would fire a couple of rounds just to see what I get. I loaded the Bergers (roughly) to where the boattail/shank junction landed at the should/neck junction of the case. I could have been on or off the rifling but with a mild load of 28.0gr Varget I figured that it didn't matter.

The new Lapua cases measured 1.158"-1.1595" (cartridge base to datum line using a Stoney Point shoulder gauge. The first firing with the light load increased the measurement to 1.163"-1.1645". I'm assuming that a subsequent full load will increase the dimension a bit farther and I can begin to adjust my dies (when I get them) from that point.

Any observations, comments or suggestions as I get this project underway?

 

[dgeesaman]

I would take the longest brass you have now and add circles of masking tape to the base until it chambers snugly. Then measure it to get an idea where your actual final headspace measurement will be.

 

[dgeesaman]

Also when I'm getting to this point (1-2 firings) I make sure to set my fired brass in the loading box upside-down if it was a tight bolt lift. These are usually the cases with the longest headspace. Saves me time on the bench determining which brass to use to set my sizing die.

 

[Charlie-NY]

I would take the longest brass you have now and add circles of masking tape to the base until it chambers snugly. Then measure it to get an idea where your actual final headspace measurement will be.

Hey now - that's a good idea. With a piece of tape being about .003", I hope it won't chamber. :>)

I was going to do the AW seating depth test but just didn't get around to yanking the ejector out. It's something I've never done before. I normally just use the Hornady OAL gauge with a piece of converted, fired brass.