I'm shooting a 700VS in .308 Winchester. The gun shoots pretty accurately considering the long throat, but one thing that has been a constant source of headaches is the neck area.

I've been using Winchester brass, un-turned, which measures right around 12 thou neck wall thickness, maybe a smidge more. Loaded rounds come out 0.330-0.331". Where the problem comes in, I think, is that the fired cases come out 0.346". Straight w/i 0.001 or so on a dial indicator, but in my mind, a bit on the large side.

Is this 0.346" fired diameter 'normal'? I've seen/heard some information to the effect it's just on one end of the SAAMI spec for this caliber, but I'm going off of hearsay and reamer dimensions, not actual SAAMI specs.

Is it worth pursuing finding brass that might have slightly thicker neck construction, such as Lapua? Even if I get up to 14-15 thou neck thickness, I'm going to still be a fair ways away from a 'snug' fit, but maybe closer to what I think I want.

Ideas, suggestions, comments?

Monte

milanuk--

I have a couple hundred Federal match 308 cases here, once fired. All measure about .346, but they have .0155 necks.

If you have the means to turn necks you'll get much better performance from cases formed and trimmed from 30-06 cases.

Hmmm... interesting. You just jogged my memory (whew, what a workout! ;p ) in that I do have about 60 Federal Gold Medal cases collecting dust out in the shop somewhere... I'll have to measure the necks on them and see what shows.

Forming .308 from .30-06, no thanks! I'm interested in a semi-large quantity of match quality cases here, so I can tumble, deprime, size, do misc. brass prep, and prime, as one 'stage', leaving myself a nice big bucket of cases primed and ready to charge w/ powder and seat a bullet. I'm debating on whether to call it quits on this batch of ~300 Winchester cases after 7 or 8 loadings (2 more 'cycles'), and was looking at getting a batch of 500 of whatever for my next generation of cases. Having to deal w/ forming that many cases from .30-06 might be just a little too much fun for me.

Thanks anyway,

Monte

I am surprised at how thin the Win cases are. Lapua average from my lot about .338 with Sieera 168's seated, and Fereral about .342 which is oversized for my hart/sako (.340) My Remington VSSF shoots extremely well with about a .345 fired neck, so don't worry... fatten up.

Consulting "Handloading" 1981 Davis and the NRA:

The SAAMI spec on the neck of the chamber of a .308 win is at the rear .3462 to .3482" and at the front from .3442 to .3462".

The SAAMI spec on the neck of the cartridge of a .308 win is at the rear from .3355 to .3435" and at the front is likewise from .3355 to .3435".

Your neck walls are a bit too thin but don't let the gap scare you. Years ago I had a 22-250 that shot pretty well. I was sold on the fact that a close fitting neck was the panacea. I took some military '06 cases with those heavy walls, sized them down in stages to 22-250 and turned the necks to give me .002" clearance in my chamber. Tons and tons of work and I just knew I was going to cut my half inch groups in less than half. WRONG! All that work and it didn't make one iota of difference.

All you try to do in handloading is to get the brass and bullet as concentric to the centerline of the bore as you can. If you have too much clearance at the neck it's possible that tight clearances at the body/shoulder still keep that bullet and neck concentric, even if you have a quarter inch clearance. Optimum is about .002" clearance for an experienced handloader. Hunting guns usually have .005" clearance, or a bit more. Benchrest chambers work with .0002", or a bit more.

Get a better lot of brass with neck walls nearer .015". Still will probably not make much difference.

My Lapua .308 brass is .015 thick at the neck. It's on about it's fifth firing mind you. I'm in the process of going thru sizing 30-06 brass down to .308 for longer and thicker necks. After reading the above hopefully I'm not wasting time As it turns out I may need to do some neck turning on the resized 30-06 brass though I don't currently own a neck turner or reamer for that matter. Fired Lapua .308 brass is measuring .345 and the resized 30-06 is measuring .344 before seating a round... to close for comfort IMHO.