Report: Thinner Neck-Walls on Latest Lapua 6mmBR Brass

Robert Whitley sampled a recent lot of Lapua 6mmBR brass and found that the neck-walls are marginally thinner, resulting in a very slightly smaller loaded neck diameter. Here is Robert’s report….

For the last few years the different boxes of Lapua 6mmBR Norma brass I have purchased (four different lots) have yielded brass with necks that measured around .269″ – .2695″ loaded. While this worked out very well in a variety of applications, sometimes I had to neck-turn that brass because it was a little too tight for an application or chamber I had. I recently received some of the latest “blue box” Lapua 6mm BR Norma brass (Lot # P00487801) and this latest lot of 6BR brass measures right around .268″ loaded (with popular 6mm bullet types). While some may bemoan the smaller neck diameter of this latest brass lot, for others, this can be a buying an opportunity to resolve an existing clearance issue with a “no neck turn” chamber. For example, if you have a .271″ “no neck-turn” type chamber, this may help resolve clearance issues that arose with other batches of brass. Or, for those who need to turn their necks to fit a tighter chamber, this new lot of 6mmBR brass has about .001″ – .0015″ less metal to remove, making the turning process that much easier.

This lot of brass (Lot # P00487801) was obtained from Graf & Sons. Since the batches of Lapua 6mmBR Norma brass that come into this country typically sell out quickly, if this .268″-loaded-neck brass is of interest to you, get some soon as it may go fast. While in years past I tried to keep my neck clearance very close to the chamber neck diameter, as time passes, I am now finding that in some situations a little more neck clearance can help remedy an accuracy or consistency issue. A certain amount of clearance is clearly needed for the proper accuracy and consistency of ammunition, but in some situations a tight neck clearance is not optimum and may be more detrimental then beneficial. We tinker with everything else with our loads and rifles, why not neck clearance? — Robert Whitley

Editor’s NOTE: If you need some new 6BR brass, but your existing cases have no-turn necks which are .269″+ loaded, you may want to segregate the newer .268-necked brass. Segregating the new brass will allow you to use a a slightly smaller diameter bushing to maintain the same amount of grip on the bullet (as before). Other than this minor change in neck diameter with this lot of brass, this Lapua 6mm BR Norma brass is essentially the identical product as it has been all along.

Visit Robert Whitley’s 6mmAR.com website for more information on Grendel-based cartridges, and his 6mmHOT.com site for info on the 6mmBR Improved Dasher, 6-6.5×47, and 6.5×47.