6.5x284 Winchester -6.5x284 norma
- Thread starter encs
- Start date
Dimensions could be different depending on who designed or requested what on their reamer but the basic cartridge is the same. I'd go with the 6.5/284 Shehane, it has a slight difference in taper. Enough to allow shooting the standard max loads without standing on the brass.
encs said:
There is no one 6.5x284 Winchester, it is a wildcat, and therefore no one standard exists for you to compare it to another round. Nominally, it's just a .284 Win necked to 6.5, but the devil is in the details.
The 6.5x284 Norma is a CIP standardized cartridge, and therefore there is a single, published standard for the round.
If you just want a standard 6.5x284 cartridge, get the Norma. Otherwise you're playing the wildcat game (in which case you may as well go with something that's not going to be 99.5% of a standard cartridge, but might have critical differences, like the aforementioned Shehane (that is the Shehane is something different)).
Yes, it's as per Catfur's response. The other distinction between the pair is in freebore and COAL. .284 Win was originally designed as a short-action cartridge and therefore has a 2.800" SAAMI maximum OAL. This severely limited the choice of bullets as anything much over 140gn has to be seated very, sometimes too deeply in the case.
The simplest version of 6.5-284 Winchester retains this characteristic with a simple switch to a 6.5mm barrel and use of a modified chamber in the neck area with appropriately necked-down brass. Hornady uses this form in its 7th edition reloading manual and simply calls the cartridge '6.5-284' noting that its choice of a short (24-inch) short-throated barrel in a T/C Contender for load development purposes severely limits attainable velocities (and of course usable charge weights although the company doesn't say that).
With lots of individual variations on the theme involving scores of chamber designs, the vast majority increasing COAL and freebore, Norma eventually stepped in and produced its long-throat version in 2000, the cartridge supported by and specified by the CIP, our version of the US SAAMI. It has settled on a COAL of 82.00mm (3.228-inch), although specs that go to the governing bodies involve many more aspects than just this alone. In effect, 6.5-284 Norma is a new cartridge and that's what most loading data is now for.
With both .284 Win (often called the 'straight 284') and its 6.5mm offspring used more often in custom built target and hunting rifles than in factory models, chamber versions still proliferate - especially for the .284 which has never had a long SAAMI version developed and adopted - and users need to be wary in initial load work-ups tailoring charges to suit the individual rifle's chamber freebore.
The simplest version of 6.5-284 Winchester retains this characteristic with a simple switch to a 6.5mm barrel and use of a modified chamber in the neck area with appropriately necked-down brass. Hornady uses this form in its 7th edition reloading manual and simply calls the cartridge '6.5-284' noting that its choice of a short (24-inch) short-throated barrel in a T/C Contender for load development purposes severely limits attainable velocities (and of course usable charge weights although the company doesn't say that).
With lots of individual variations on the theme involving scores of chamber designs, the vast majority increasing COAL and freebore, Norma eventually stepped in and produced its long-throat version in 2000, the cartridge supported by and specified by the CIP, our version of the US SAAMI. It has settled on a COAL of 82.00mm (3.228-inch), although specs that go to the governing bodies involve many more aspects than just this alone. In effect, 6.5-284 Norma is a new cartridge and that's what most loading data is now for.
With both .284 Win (often called the 'straight 284') and its 6.5mm offspring used more often in custom built target and hunting rifles than in factory models, chamber versions still proliferate - especially for the .284 which has never had a long SAAMI version developed and adopted - and users need to be wary in initial load work-ups tailoring charges to suit the individual rifle's chamber freebore.
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