Reloading 284 Winchester for a BLR

This has probably already been covered but couldn't find any obvious reference, so here goes.

Reloading the cartridge for an old mate.

Knocked up a couple of dummy rounds using Nos BT 140 grn and 150 grn using specified COAL. Fits in the magazine, just! Projectile though, seated that deeply into case I suspect I'll need to crimp the case mouth. Could use 120 grn, much less of an issue being somewhat shorter. Not sure that the barrel rifling twist will stabilize them, I think it's 1 in 10 but not sure. Google hasn't helped.

Secondly am using 2209, no specific data but I'm pretty sure it's equivalent to IMR4350. That said I don't want to bet my mate's well being on my semi educated guess.

If anyone's dealt with the matter before, advice will be appreciated.

Cheers

Loaded for BLR in .308, you may need to be careful to completely resize each time as action doesn't have much cam power. Really nice rifles once trigger is sorted. No help on 284 sorry

Can't help with BLR specifics but I run 150 nbt and 2209 with 55.5g seated way out. Suggest starting at 50g and work up. Also have a look at adi powder data as there is heaps of info there.

Not a levee action, but I was running a 140 Nosler AB in my 20in 284 (bolt action) with 2209. 54.3gn but COL 3.08, so longer than SAAMI. You’d want to back off that load by 2-3 grains for shorter COL. I was getting 2890fps with this load.

Hodgdon and ADI have data. AR2209 is H4350. Getting max loads in will be a challenge and I would stay away from them.
GPM.