Q: I am a longtime reader of your column and have come to trust and rely upon the information. My son and I both use Browning BLRs in .300 WSM for general hunting but I’ve had problems with short case life.
After I read your article on correct headspacing, I bought a Hornady headspace comparator gauge, which opened my eyes to some problems. I discarded my Remington brass and replaced it with 200 Federal cases. I cleaned and prepped the cases and full-length sized them as per the manufacturer’s instructions, only to find I had shortened the cases by five thou (0.127mm) compared with a new factory case and factory loaded ammo.
The Hornady headspace gauge showed the following lengths: new Federal brass and factory ammo measured 1.740” (44.196mm); once fired cases from my BLR 1.745” (44.323mm); and full length resized cases 1.735” (44.069mm). So it appears my new cases are now 10 thou (0.254mm) too short for my BLR.
Can you tell me how to fire-form this brass to salvage the cases? I’ve re-adjusted the full-length sizing die to 1.744” (44.298mm) and handloads are feeding and ejecting well.
Accuracy of the BLR is fairly ordinary — two inches (5cm) at 100 metres is not uncommon. I had a Que adjustable barrel tuner on a .270 Ackley. All I had to do was work up a safe load and tune the barrel to suit that load and it would group into .75 MOA all day.
I’d like to obtain a Que for my BLR, but I can’t find any dealers that import them any more. Do you know any Aussie company that makes a similar barrel tuner? Mine didn’t have a muzzle brake.
Brian Duncombe
A: It appears that you have overdone the full-length resizing of your .300 WSM brass. But did you full-length size the cases before they were fired in your rifle or after they’d been fired?
All I do with new brass is run their necks over the neck expander button to round their mouths out and chamfer them to make bullet seating easier.
The industry maximum for allowable headspace measurement for a rimless bottleneck case is .004” (0.102mm) and .010” is dangerous.
You can’t fire-form those short cases to fill the chamber, but there is a simple solution. Get a tapered neck expander button, one larger than .308 (.323 or .338) and run it through the necks of your cases to expand the necks. Then lube a case and carefully run it into your full-length .300 WSM die set to miss contacting the shellholder by about 1/16” (1.6mm) or so, then try to chamber it.
It won’t go fully in the first time, so size it down by stages. When it chambers with a slight feel, headspace will be correct. Lock your die in the press and treat the rest of your cases the same way.
Redding makes tapered sizing buttons, but not one that goes from .308 to .323 or .338. But I am sure that 7mm to .35 will do the job for you. Ask for number 16356.
Regarding the accuracy of your BLR, I wouldn’t expect that type of rifle with a light barrel to shoot better than 1½ MOA, but it is a hunting rifle, not a benchrest rifle.
Short case life is usually from using hot loads, but since you didn’t tell me what your loads are, I cannot comment other than to say that the front-locking BLR will contain high-pressure loads without any of the problems associated with traditional lever-guns.
The Browning BOSS was a gimmick that changed barrel vibrations and was dropped years ago. It wouldn’t have been much use on your BLR anyway, so forget it. I found that to find the so-called sweet spot took lots of experimenting with different loads and after all that it only worked with one particular load. A costly exercise indeed.
Forget these ‘tuners’ as they won’t work with the BLR. Find a load that shoots 1½ MOA groups, which is as good as that rifle will do.
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