Do I need to full length size new rifle brass
- Thread starter Furlan1098R
- Start date
- Location
- Western Manitoba
I have no experience with Lapua brass, or how they are packaged. Most that I work with have come loose in a bag - Winchester, Remington, PPU, Norma (from private sellers). Not unusual to see the mouths of the necks are dinged, or bent inwards. I set up my Full Length sizing die in RCBS Rockchucker press with about 1/8" or more gap between shell holder and bottom of die, and run them all through - sizes most of the length of the neck without touching the body or shoulder and gets the neck and mouth all round. Often touch the inside edge of mouth with chamfering tool if I am loading square base bullets. Worth it to check the batches for length, although 99% are fine. I load those up and go hunting - work fine. For finest precision, want to actually load and fire, to fully fill out to your chamber - then can get as fussy as you want for re-sizing after that fire-forming.
Neck sizing would be sufficient - you don't need to bump the shoulder on a virgin case. I have used Lapua and other brands right out of the box without sizing the neck too, I just did this in my 260 Rem. Accuracy was fine and it saved me some time. I don't get serious about load development until the brass has been fired in my chamber.
For new to me brass (which is new brass of a make I have never used before) I give a quick inspection to see if any are severely deformed. If not, I just fill them with a reduced powder charge, seat a relatively inexpensive bullet and head out to the range to shoot at the gongs. This gets the fire forming about 90-95% of the way. There is always some springback. Next reload is neck size with a Lee collet neck die, a more accurate amount of powder, same bullet and back to the range to see what the velocities and accuracy are like on paper. This step gets the case about 98-99% fireformed and gives me some info about what to expect as I approach loads more consistent with known accuracy. Next reload is thorough cleaning in a vibratory cleaner with fresh media for an hour or so. Then full length size, setting the shoulder back 1 to 1.5thou from my measured rifle's chamber. Then trim to length. Then neck turn. Then reload to perform ladder tests with quality bullets. From this point on they are cleaned every time, get body sized every third reload, and neck sized/shoulder bumped every reload. I monitor length and trim each lot to length at the same time as necessary after neck sizing/shoulder bumping.
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There is one other thing I will do though and that's make sure the case mouths are not longer on one side than the other. So, I take the time to trim all of them to minimum length, chamfer the edges. I also measure the run out on several, just to make sure they're reasonably straight. If they're not, then I will partially resize to get the shoulder and necks aligned.
As far as accuracy goes???? That may just depend on the rifle more than anything else. I've shot some of my tightest groups with new brass that has only had the case mouths cleaned up and trimmed.
I have ONE rifle that shoots really well with full length resized brass. It's an old 6.5x57 MS. Twist rate is slower than most 6.5 bores and it doesn't shoot anything heavier/longer than 130 grain boat tails well. It loves the ttsx 129 grain pills in new S&B brass.
If your chamber/throat/leade is on the max side of spec, full length resizing may not be your go to choice.
