Ok, so I bought some new Lapua 300 win mag brass for my 7-300 Win Mag, when my nosler stuff gives out. They're on 10 firings now and still holding up great. I use a Redding FL bushing sizer with a 308" bushing. Loaded OD round is .311" and OD neck of fired case is .313" COAL is 3.490" Headspace measures 2.271" with .002" bump and they chamber great. No scrapes on the head of the case.
So I made a dummy round with 1 one of the Lapua cases. Ran it through the sizer, sized most of the neck but left a donut type right at the base of the neck. The headspace is 2.261" and the OD unfired brand new lapua case neck after sizing is .316" I loaded it with a 180g ELDM to 3.490" After seating the OD loaded round was also .316" then tried to chamber it. It was pretty stiff/hard but it went. However, I noticed it left a nice shiny circular bolt face swipe on the case head. Trying to figure out where my problem is with that. I don't want to tear up this new lapua brass. Do I need to turn these necks down just a hair, or would a different size bushing fix it? I'm thinking I need to turn the necks down .003" to the outside fired neck dimensions of .313" Or would I need to do .005" since the OD loaded round of Nosler brass is .311" and Lapua is .316"?
And secondly, if they do need neck turned, does anyone know someone who does that on the side and what the approx cost is? Not sure I can justify $180 on a PMA tool for 1 rifle and set of brass in my arsenal that needs turned. Once its turned down, it'll wear out a whole barrel...
Hope that made some sense.
So I made a dummy round with 1 one of the Lapua cases. Ran it through the sizer, sized most of the neck but left a donut type right at the base of the neck. The headspace is 2.261" and the OD unfired brand new lapua case neck after sizing is .316" I loaded it with a 180g ELDM to 3.490" After seating the OD loaded round was also .316" then tried to chamber it. It was pretty stiff/hard but it went. However, I noticed it left a nice shiny circular bolt face swipe on the case head. Trying to figure out where my problem is with that. I don't want to tear up this new lapua brass. Do I need to turn these necks down just a hair, or would a different size bushing fix it? I'm thinking I need to turn the necks down .003" to the outside fired neck dimensions of .313" Or would I need to do .005" since the OD loaded round of Nosler brass is .311" and Lapua is .316"?
And secondly, if they do need neck turned, does anyone know someone who does that on the side and what the approx cost is? Not sure I can justify $180 on a PMA tool for 1 rifle and set of brass in my arsenal that needs turned. Once its turned down, it'll wear out a whole barrel...
Hope that made some sense.
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