WOW!! 15 years later I'm still fighting the same Weatherby fanatazies
Nosler reloading Guide #5 180 gr. with safe IMR 4350 load
.300 Weatherby
3088 fps
76 gr. IMR 4350
26 in. barrel
300 WM
3130 fps
70 gr. IMR 4350
24 in. barrel
Those 6.5 RPM numbers look sandbagged based on the apparent size of the case.
The lowly old 6.5 Rem Mag shoots those bullets faster without even trying.
Edit: I dug around for the case capacity of the 6.5 RPM which is reported at 81 gr H2O
6.5 RM is 70.
6.5 PRC is near 70 iirc




WOW!! 15 years later I'm still fighting the same Weatherby fanatazies
Nosler reloading Guide #5 180 gr. with safe IMR 4350 load
.300 Weatherby
3088 fps
76 gr. IMR 4350
26 in. barrel
300 WM
3130 fps
70 gr. IMR 4350
24 in. barrel
My 300 Wby is triggering the crono at 3250 fps with 180's and 7828.
I ordered a 6.5 RPM Backcountry, hopefully its here this year sometime !
I also picked up a box of Weatherby 6.5 RPM ammo loaded with 140gr Accubonds and pulled the powder out of it and it had 64.6grs of powder not sure what it is but looks like R26,
I measured the H20 volume and I had 80.1grs , a recent article measured 82.5, its definitely just an extended 6.5-284
I see a 270 RPM, 280 RPM and 300 RPM in the near future !
The case measurements
rim- .463
base- .490
shoulder .463
6.5-284 / 6.5 RPM / 280AI / empty 6.5 RPM
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Would make a neat four to five down .375, that case.
Theres NO way a 264 win mag holds that much water more like about 79-80 grs - RJ
3075fps with a 140gr isn't anything special.
Surely this will help me kill deer at less then 100m better!

I’ve been dreaming lately of a .284 Winchester that was lengthened to a 7RM OAL. What’s not to like? Then I started dreaming about actually making one and investing heavily into it. Then I realized this it’s basically a 7mm/6.5 RPM and that it’s likely already on the shelf at Weatherby just waiting for the 6.5 to lose its 1st year shine and then they’ll drop the 7RPM. I just bought a 284 long action that I don’t really want to keep as so, as I just built a 7-08 and was thinking how or what to rechamber it to. Maybe I should just wait till the 7RPM comes out? That would work perfectly with that existing chamber. 7RM is my all time favourite, but rechambering to another 7RM would involve opening up the bolt face, which isn’t a big deal, but gives me an excuse to play with something new![]()
That’s the one Buckmastr
Yeah I’ll probably throw a few rounds through and see what happens on the chrony




























