I think I know the answer but other opinions are always welcome here.I'm going to load 6.5x55 swedish for my new Tikka T3.I bought 50 new Lapua brass cases.I dropped one in the chamber ,seated and ejected perfect,length appears to be .016 short by my caliper.I want to (fireform)neck size only after the first firing of these when reloading.
Would YOU run them thru a full length sizer or not?I have to believe the FL die could do more harm than good.Also should I start light or are full power loads ok for first firing.
I plan on graphing the Win. Fl loads I bought to sight in and start the reloads at that velocity and work up.
Sound like a plan?
Any pet loads out there?
Thanks

Based on past experience (though not with Lapua cases) I'd run them through a FL die to uniform them. You could use them with full power loads assuming the load your will be using was worked up using the same (kind) of brass, bullet, powder and primer before. If not, cut back 10% and work up, preferably using a chron.

OK..it's the length that is about .016" short, not headspace....no problem, most cases are a lot closer to min. than to max. and a bit short does no harm at all.

Would still resize them...proably with the die backed up in the dress enough to not fully size, just size enough to get neck tension equal. Then I'd proably find the shortest cse of the lot, and trim the rest to match it just to have them all start off even.

Same as Cossack and Ribbonstone, I would resize them just to have the same uniformity especially with neck tension.

One thing I've notices with most new brass is they will have the necks dinged, oval and sometimes just bent. I always full length resized new brass. It's dead soft from the factory and even if you only neck size from then on It will be the best time to do a full length sizing.

I then neck anneal every fifth firings along with checking the inside for incipient case seperation. This is done with a bent paper clip run up and down the inside of the case.

Good luck with your new brass and keep shooting.

A short scroll down the page to the "Similar Threads" section contains previous posts on this question and will give you lots of thoughts.

New brass, resize?

YES

Mostly, I would agree with the above forum members. In this case, I think that I would fire form them as they are. You have already measured them and checked that they chamber fine. After fire forming, give them the full treatment. I would use up a can of powder that has enough left for the task at hand, and perhaps use some bullets that I wouldn't use for anything except plinking. You will clean your bench a little and will minimize working your new brass.
My opinion only.
Cheezywan

I have done it both ways and gotten good results both ways, that said, the only reasons I have gone with out FL sizing is before I knew better and If I need to get ammo loaded fast