THE HANDLOADING BENCH
6mm NORMA BENCH REST (Part 5)
I look for the shoulder to only just be pushed back, by 0.001-0.002 inches, to give easy chambering but a snug fit. With the tight chamber from Norman Clark’s reamer, there is very little expansion either in the case- body or neck, so sizing requires little effort on either of these powerful single stage presses after applying a thin coating of Imperial Sizing Die Wax to the case using the thumb and finger.
After some initial enthusiasm, I’ve never bothered much about preparing the Lapua brass that I’ve used throughout with this cartridge. I have a look through the flash-holes on new brass to check there is no minor flashing from the drilling operation then run them over a case neck mike measuring three points, batching them as needed to keep variations small – all cases within the same smallest and largest reading range, individual cases seeing no more than 0.0004 inch variation over the three readings.
Berger’s new 87gn 6mm VLD, the orange box showing it is a thin-jacket ‘Hunting’ model. “Also Excellent for Targets” it says on the box – but not in the UK!
for mid-twist rate 6BR owners, it is a great design for shooters with accurate heavy-barrel .243 Win rifles.
Mechanical Bits Although I use a Co-Ax press these days for this and similar cartridges, most of my 6BR loads came off a Lee Classic Cast single-stage press that preceded the Forster model on my bench. The big Lee is great value for money and produced very concentric results in conjunction with Forster dies. Nevertheless, I reckon the Co-Ax plus Forster or Redding dies provide as good a combination as you’ll find short of going to BR Wilson type ‘hand dies’ and an arbour press.
As noted previously, I have a Forster FL sizer with an oversize (0.265 inch) honed-out neck section to reduce case-neck sizing to a minimum. All cases are full-length sized with a close watch kept on the headspace dimensions by comparing a selection of fireformed cases against those coming out of the die using callipers and a Stoney-Point / Hornady L-N-L comparator body with a #‘B’ (0.350 inch aperture) headspace bushing.
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I might or might not batch them after weighing, but the overall range is usually so small out of the box it isn’t worthwhile, so it’s more a check to cull out the very occasional ‘rogue’ case. It’s always worth checking neck thickness and weight variations on a new production lot though to ensure they’re up to Lapua’s usual standards. I did give 50 selected cases a light neck-turn reducing neck thickness variations to near zero and to find out how it affected group sizes but, to be honest, I couldn’t see any change one way or the other and have never bothered repeating the exercise. I also used to ‘uniform’ primer pockets, but reckon they’re near perfect as they leave the factory, so that’s another onerous job that’s been dropped.
With most older lots of Lapua brass close to 0.013 inch neck-wall thickness (I believe more recent ‘Blue Box’ batches may run a half-thou’ thinner), my Forster sizer die’s neck section 0.265 inch diameter is a bit on the tight side for a round that will have an O/D around 0.269 inches, slightly less for Lapua Scenars and slightly more for Berger BTs or VLDs, even after the usual 0.001 inch ‘spring-back’.
I chose this size to allow for possible factory brass lot to lot neck thickness variations, to encompass 0.0005-0.001 inch wall reductions from a clean-up neck-turn, also because I often loaded Lapua’s Silver Scenar factory moly-coated bullets in the rifle’s early 6BR days. Coated bullets need an extra thou’ of neck tension over ‘naked’ examples, say 0.003 inches compared to 0.002 inches.
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