By Bruce Potts
Tuesday, 20 March 2007
.338 BR calibre review: The .338 BR is just the thing for the woodland stalker who wants a calibre that can produce one-shot kills without damaging the meat.
.338 BR calibre review.
I have come to form the opinion that less is more with woodland deerstalking: enough calibre without overkill is what I want.
The benefits not only manifest themselves at the shooter's end with milder recoil, better placed shots and lower noise levels but also, while remaining legal and humane, a kill is ensured without excessive carcase attrition.
Many cartridges fall into this category, but one that springs to mind is the Bench Rest (BR), originally designed by Jim Stekl, of Remington Arms, in the mid-1970s.
The mid-size BR or .1/2 size .308 case is coming into its own. This is not from its original 7mm calibre configuration, but from its many forms of wildcatted sizes, starting from .17 all the way up to .35 calibre.
I wanted a woodland deer cartridge that would propel a heavy bullet of 250 grains at deer-legal energy figures with small powder capacity, light recoil and ease of moderator use, yet exhibiting humane clean kills. Mostly I shoot at 100 yards unless in Scotland, when a 200-yard range is not uncommon. Though .243s and .308s are excellent, for many uses they are overkill. I wanted an efficient, humane, accurate, non-meat-damaging cartridge. Perhaps the .338 calibre derivative of the BR case would be it.
Sourcing the kit
I needed to source a donor gun or action to have rebarrelled and I needed a competent gunsmith, as well as the essential moderator, reamers, dies and all the paraphernalia necessary for any 'unusual' project. Usually I would use Pac-nor from Oregon, in the US, to supply a barrel and reamer, however this time Steve Bowers, gunsmith for the job, sourced a Border barrel from Scotland.
I used Pacific Reamers, in the US, for the chamber reamers. Ordering a barrel for a normal calibre is not usually a problem - length and twist rates are pretty standardised based on the bullet weight and type. However, a 250-grain projectile travelling supersonic at 2,200fps posed a problem as to what twist and length to choose.
Logic suggested that a 250-grain bullet seated in a relatively short case would only offer a small powder capacity, but how much?
With no load data available, I turned to the Quickload ballistics programme. With this, I was able to design a .338 BR case based on a 6mm BR diagram to project predicted charge weights, bullet choices and powder compatibility. It's an invaluable tool under these circumstances and allowed me to hone some safe and deer legal loads to try out.
Trial and error
The water capacity of a .338 BR case is 40.5 grains with Lapua 6mm BR brass, so 25 grains of powder would achieve a non-compressed load with a bullet seated. It had to be a relatively fast powder to achieve supersonic velocities in the 2,200fps range with a 250-grain bullet and still remain deer legal in England and Wales. Lighter bullets would be necessary to meet the 2,450fps velocity minimum in Scotland, however.
With these two predictions I realised that for a .338 BR to work I would need a short, fast twist if accuracy and stability were to be achieved.
It fact a twist rate of one-in-eight was settled on, as this would stabilise up to 250-grain projectiles and, as it turned out, 300-grain as well, though one-in-seven would be better for 300-grain. This was achieved from a 14.5in barrel (16in overall with 14.5 of rifling). All powder was burned within this length and the bullet was stabilised. Any additional length would be superfluous and might cause additional and unwanted fouling problems. Being short, the barrel could be fat for rigidity, but I wanted to use a sound moderator. I plumped for an effective and straightforward muzzle-mounted PES 38mm diameter. It is a great system and the rifle is only 45in with a sound moderator fitted - perfect as a close-quarter woodland rifle.
The barrel was mated to a Tikka M65 action, sourced from Macleod's of Tain, in Scotland, and blueprinted by Steve in his workshop, producing the best action blueprints anyone could ask for. Once you have gone this far, it would be sacrilege not to hone the trigger carefully. Relatively heavy at 3lb, but a superbly crisp clean-breaking trigger was the outcome. I elected to save the original stock, which, despite its heavy look, was light and tactile, and the adjustable cheek-piece gave a correct scope-eye alignment. Bedding the action for consistency was left alone at the initial testing stage. If the rifle showed promise, then a full synthetic bed would be added later. The whole stock was covered in a high-impact green crinkle military paint to repel the elements.
With the rifle sorted, the cartridge case needed to be formed - no factory brass is available. Case forming involves expanding 6mm BR Lapua or Norma brass up in stages to .338 diameter with K&M mandrels supplied from Sinclair International. Take your time and lubricate the necks well until the final stage where a degree of neck turning is essential to eliminate a forming bulge at the base of the neck. Reload and fire-form the brass as usual.
The .338 BR is a small case and with a 250-grain flat base bullet, the overall length was 2.299in, which meant the bullet seated a long way into the case, reducing capacity from 42.5 to 30 grains or less useable. This was actually quite handy, as relatively fast powders of small weights are necessary to launch a bullet to deer-legal 1,700ft/lb (England and Wales) from only a short 14.5in barrel. Quickload, a computer ballistics programme supplied from JMS Arms, suggested VIT N120 powder with a charge weight of 26 grains maximum to achieve 100.1% load-density, 100% burn-rate and the magical 1,827fps and 1,854ft/lb. Alternatives would be Benchmark, a medium burn-rate that at 29 grains would give 1,815fps and 1,829ft/lb, or the slightly faster burning powders of Alliant RL7 and RL10X.
Get a load of this
I started with 24 grains of Vit N120 and accuracy at 100 yards was great - three-shot groups measured a scant 0.5in. As the break in procedure progressed the group sizes shrank still further. But 24 grains was not quite deer-legal so an increase up to 25.8 grains peaked at 1,816fps and 1,832ft/lbs and 0.45in groups.
I settled on a Hornady 250-grain round-nose flat-base bullet - it best fitted my criteria as a short-range deer round. I did try the Bench Mark, which gave similar results. One thing to remember when loading this round is the throat on the barrel allowed a long bullet length. If the bullet was to be seated shorter, pressure would rise accordingly so, as with all reloading, take care.
This was conceived as a short-range, low meat-damage round and the trajectory at 200 yards does rainbow. But when zeroed at 30 yards (close-range) a 250-grain round-nose Hornady is 1.6in high at 100 yards, 1.2in low at 150 yards and 7.8in low at 200 yards. Up to 150 yards is no problem if you take a heart or lung shot.
The rifle shot beautifully - the .338 BR has all the potential to be a superb woodland deer round. The Bowers custom rifle has proven itself on roe and fallow with none of the spoiled meat from using a lighter, higher velocity bullet.
Try as I might, I could not make the rifle deer-legal for Scotland with its 2,450fps - a shame, as the .338 BR would make a great woodland stag rifle.
However, it offers the stalker who appreciates a novel and specialised cartridge a new approach to woodland deer management.
SHOOTING GAZETTE: Driven shooting's finest journal
BRITAINíS BIGGEST & BEST SHOOTING MAGAZINE JUNE 2013 £3.60
Don't miss this week's Shooting Times (on sale Wednesday 1st May)! FREE PRIZE DRAW - win a Bowman clay trap worth £1,000! Plus, who is the UK's top Shot keeper? Buy your copy today!