603 Country Wrote:Depends on who you ask. I always trim the Lapua brass, but usually don’t do a full resize. The main reason I trim the brass is that I use an RCBS Trimpro with the 3 way trimmer and get the case mouth like I prefer.

37L1 Wrote:I mandrel the neck and chamfer. No trim or full length size.

Old Bob Wrote:I'll chime in for the neck straightening chore for new brass. I've never had a bunch of new brass that didn't have some pieces with dented or oval shaped case mouths. Used to do a full case sizing, trim & chamfer of the whole lot but found just running all the cases over a mandrel would clean up any bad case necks. What I do then is measure the case lengths to see if any need trimming. Will still chamfer all cases. If any shooter wants good, accurate ammo, you gotta do this.

DIANEB Wrote:Ok I did everything you posted and they all are looking great...
One more question, the flash holes are kinda small should I do anything to them?
Thanks again
.

Klem Wrote:No need, Lapua finish of their flash holes is as good as any.

There is an online debate by the long range/bench-rester shooters as to whether Lapua drills or punches their flash holes, and whether that is even an issue. Bryan Litz in his Modern Advancement Volume II reportedly claims they are drilled (I have never read this book). My thoughts are it does not matter as we only worry about whether there is any need for internal chamfering. I have never seen the need to do this with Lapua; their quality control and finish is excellent and no doubt why they are the preferred brand for high-end competition.

If you are concerned about their 1.5mm (0.059") holes being small then it's perfectly fine for primer spit. The only time primer holes are an issue for me is if you tumble in walnut media after removing the primer. if your media is small enough there will be pieces clogging the occasional hole. You can easily check by holding cases up to the light.

European small primer holes 0.059" are a bit narrower than the US 0.062" but Grendel die manufacturers have deprime stems that cope with this without sticking.

No need to drill wider and in fact this may be dangerous. No need to chamfer. I read online that Jack Nary did a test of 6BR flash holes seeing if chamfering or drilling made any difference to results on target. With Bench Rest guns you can see if these minimalist efforts make a difference. Apparently, they did not. So, if Bench Resters can't see a difference then we won't either.

Klem Wrote:I size for consistent neck tension and chamfer inside necks

Zeneffect Wrote:Iduno, for 1st firing I care a lot less as i was not in control of the sizing process. Sd and es are basically never as good as after firing and resizing. Once fired from the intended chamber, then the attention to detail becomes hypercritical. I would rather have my case capacity established for my chamber than by factory dies and work from there. new brass I always just use as plinkers or sighters. Anything I care to establish reference groups, or compete with will be fired brass from that gun.