6.5 RPM what is it good for?

[Horsemen61]

Hello all,

Let me start by saying I'm a 6.5 Junkie I love the .264 diameter bullets but I don't know anything about this cartridge so I'd love to learn about it

 

[Zen Archery]

What's any new cartridge good for?
+200-250 over the 65CM
+100-150 over the 65PRC
So if speed is your game (definitely a game Weatherby likes to play) then you have your answer.

 

[Calvin45]

What's any new cartridge good for?
+200-250 over the 65CM
+100-150 over the 65PRC
So if speed is your game (definitely a game Weatherby likes to play) then you have your answer.

I think it also really finds its niche in weatherbys ultralight type rifles. It's a less "beefy" bolt and bolt face and receiver than the full size belted magnums

 

[sable tireur]

For the folks that this matters, it is a beltless case with a .473 bolt face and .284 body shape and size. The case capacity is 84 grains so it's about 2 grains more than the .264 Win. Mag. The OAL is listed as being 3.340" which is a standard magazine length.

 

[just_jon]

If speed is your game, step on up to the 6.5-300 Wby. Mine drives the 156 Berger more than 500 fps faster than a 6.5 CM (3317 vs 2779 fps 26" barrel). Looking at QL, the 6.5 RPM will only get you to around 2950-3000 fps with the same bullet.

 

[6.5x300 WBY]

If speed is your game, step on up to the 6.5-300 Wby. Mine drives the 156 Berger more than 500 fps faster than a 6.5 CM (3317 vs 2779 fps 26" barrel). Looking at QL, the 6.5 RPM will only get you to around 2950-3000 fps with the same bullet.

Love my 6.5x300 bee too. Working up a load for Bergers 153.5 Hybrids and US869 and I am at 3250 with zero pressure. Gonna see where pressure is and drop back a grain. It's gonna be a hammer.

 

[NorthernShot]

Hello all,

Let me start by saying I'm a 6.5 Junkie I love the .264 diameter bullets but I don't know anything about this cartridge so I'd love to learn about it

Hey Horsemen61,

I don't have one, but I have a 6.5-300 Weatherby mag. But the idea of the 6.5 RPM was to maximize the 6 lug action that Weatherby produces for their standard length action. So they blew out a 284 and lengthened it to increase powder capacity and allow a magnum cartridge fit in their lights action and then developed the Backcountry rifle for it. Lightweight rifle that hits harder than most can usually get that light while remaining stock off the shelf.

It's faster than the PRC by 50-100 fps and is a cool rebated rim Weatherby cartridge. It's not as fast or overbore as the 26 Nosler or the big daddy 6.5-300 Wby though.

 

[K.E.C. Darkside]

If speed is your game, step on up to the 6.5-300 Wby. Mine drives the 156 Berger more than 500 fps faster than a 6.5 CM (3317 vs 2779 fps 26" barrel). Looking at QL, the 6.5 RPM will only get you to around 2950-3000 fps with the same bullet.

Howdy Jon
What powder are you using for the 156's
3317 is boot scooting.
GO MOUNTAINEERS.

 

[just_jon]

Howdy Jon
What powder are you using for the 156's
3317 is boot scooting.
GO MOUNTAINEERS.

Hey David. I used Ramshot LRT which I believe you had recommended when I bought the rifle from you. I tested from 84.5 to 86.5 in .5 grain increments and got 3172, 3168, 3213, 3258 and 3317. I was shocked at the velocity as QL estimated I would top out around 3170 which is about where I ended up with US869, N570 and RL33. Bolt lift was a tad stiff at 86.5, but brass showed no signs of excess pressure. Accuracy was sub-moa for a charge weights, I plan on backing off to 85.5 which shot under 1/4";@ 100.

Hope your Mountaineers are having a better afternoon that my Nittany Lions, They stunk up the 1st half at USC, but are mounting a comeback.

Jon

 

[K.E.C. Darkside]

Hey David. I used Ramshot LRT which I believe you had recommended when I bought the rifle from you. I tested from 84.5 to 86.5 in .5 grain increments and got 3172, 3168, 3213, 3258 and 3317. I was shocked at the velocity as QL estimated I would top out around 3170 which is about where I ended up with US869, N570 and RL33. Bolt lift was a tad stiff at 86.5, but brass showed no signs of excess pressure. Accuracy was sub-moa for a charge weights, I plan on backing off to 85.5 which shot under 1/4";@ 100.

Hope your Mountaineers are having a better afternoon that my Nittany Lions, They stunk up the 1st half at USC, but are mounting a comeback.

Jon

But the Lions Win. WOW
Good for them.

 

[Calvin45]

Hey David. I used Ramshot LRT which I believe you had recommended when I bought the rifle from you. I tested from 84.5 to 86.5 in .5 grain increments and got 3172, 3168, 3213, 3258 and 3317. I was shocked at the velocity as QL estimated I would top out around 3170 which is about where I ended up with US869, N570 and RL33. Bolt lift was a tad stiff at 86.5, but brass showed no signs of excess pressure. Accuracy was sub-moa for a charge weights, I plan on backing off to 85.5 which shot under 1/4";@ 100.

Hope your Mountaineers are having a better afternoon that my Nittany Lions, They stunk up the 1st half at USC, but are mounting a comeback.

Jon

But the Lions Win. WOW
Good for them.

By any chance have either of you 6.5-300 shooters ever fiddled around with seeing how fast you can drive light for caliber bullets?
I know that's not what it's for, it's impractical to do, etc…but just thought I'd ask as I'm curious about this

 

[K.E.C. Darkside]

By any chance have either of you 6.5-300 shooters ever fiddled around with seeing how fast you can drive light for caliber bullets?
I know that's not what it's for, it's impractical to do, etc…but just thought I'd ask as I'm curious about this

Jon better at that then I am.
I played with 124 H.H. with the 6.5/300
I would have to look in my notebook to tell you the speed. Thanks for inquiring.

 

[6.5x300 WBY]

Hey David. I used Ramshot LRT which I believe you had recommended when I bought the rifle from you. I tested from 84.5 to 86.5 in .5 grain increments and got 3172, 3168, 3213, 3258 and 3317. I was shocked at the velocity as QL estimated I would top out around 3170 which is about where I ended up with US869, N570 and RL33. Bolt lift was a tad stiff at 86.5, but brass showed no signs of excess pressure. Accuracy was sub-moa for a charge weights, I plan on backing off to 85.5 which shot under 1/4";@ 100.

Hope your Mountaineers are having a better afternoon that my Nittany Lions, They stunk up the 1st half at USC, but are mounting a comeback.

Jon

Jon, seriously you topped out at 3170 with US869? I understand topping out with N570 as I did as well at 3150. Very disappointed to say the least.
But US869 has been the best powder I played with. My 153.5 BERGERS are past 3250 with zero pressure. As soon as it cools off to sub 50° I'll be back pushing forward to find pressure. I feel 3300-3350 should be very easy. Just shocked at you peaked at 3170 with US869.
Is your rifle a Weatherby or ? Just trying to figure how you topped out so low with US869.

 

[just_jon]

By any chance have either of you 6.5-300 shooters ever fiddled around with seeing how fast you can drive light for caliber bullets?
I know that's not what it's for, it's impractical to do, etc…but just thought I'd ask as I'm curious about this

I've tested the 123AH and 124HH:

123AH
RL17: 71.0 gr @ 3580 fps. Hit pressure at 70.0 grains.
RL22: 78.0 gr @ 3507 fps. Hit pressure at 77.0 grains.
IMR 7828 SSC: 78.0 gr @ 3,385 fps. Never got to pressure.
H4350: 70.5 @ 3,457 fps. Hit pressure at 70.5 grains.

124HH
IMR 7828 SSC: 77.5 gr @ 3426 fps. Never got to pressure.
RL25: 80.0 gr @ 3381 fps. Never got to pressure.
N570: 81.0 gr @ 3573). Never got to pressure.

I have a bunch of 80HHT and 85HH that I plan on testing this fall. QL estimates RL16 can push the 85HH at 4240 fps. The 80HHT should do a bit better.