Weatherby has also published data comparing the 6.5 WBY RPM to other 6.5mm cartridges. For example, the 6.5 Weatherby RPM is capable of pushing a 140-grain Nosler Accubond bullet to 3,075 fps which, according to the company, is 146 fps more than .264 Win Mag (2,929 fps), 325 fps more than 6.5-284 Norma (2,750 fps) and 420 fps more than .260 Remington (2,655 fps) cartridges loaded with the same bullet.

With a reported case capacity that is nearly identical to the 264 WM (and the edge going to the 264) I'm dubious of the rpm besting it by 150 fps ...

Speaking of dubious, check out the 'comparison' velocities they list for the other cartridges.

I have no doubt the Wby 6.5 RPM will out run the 264. The two diameter throating in the 264 makes seating one diameter bullets deeper using up some powder space. the 6.5 RPM is a standard throat .2645 in diameter .188 long giving more powder space. Time will tell. Just sayin.

Velocity listed for the 6.5-284 Norma (2,750 fps) is bullschit.

All comparisons are odious and Weatherby's add copy writers like to stack the deck. The technicians should write the factual numbers. Look at the 6.5x300 trajectories, they use a 3 or 400 yard zero and compare it to other cartridges with a 200 yard zero. Also they use factory loads compared to hand loads. What pressure is the Weatherby? I bet it is 65,000 compared to 64,000 for the 264 Win.

They would not be the first to embellish stats on new cartridges and rifles. On the other hand, all the Weatherby factory loads I fired in 7mm and .300 wby met the advertised velocity over a chronograph. Ymmv

Don't you guys remember when a 300WSM would out run a 300 WM despite less powder capacity simply due to efficient case design. Sounds great in all the magazines despite it defying physics.

My 26” Kreiger 6.5-284 will push 140’s at 3K fps over 48 gr. RL-17. No problem with half inch groups and no pressure issues. Primers OK, effortless extraction. Lapua brass not stressed.

DF

22” barrel 260Rem will do 2750 with a 140 Hornady. That’s not leaning on the powder scale either. Bad choice of marketing strategy.

This should shed some light on where it sits in the 6.5 family.

Seems to me like a nice place to be.

I doubt they're trying to take over the world with this, just appeal to Weathery-minded folks who want something "special". If the rifle I saw is what they're hanging their hat on for this, price alone will keep it from becoming a standard of any sort. What really matters is: will they make money on it, either on its own or by the enthusiasm it creates in Weatherby stuff in general?

I'm long past the point where I believe a new cartridge is going to change my life. BTW, has anyone figured out how many 6.5 caliber cartridges are out now? Gotta be nipping at .30's heels at least, counting ones currently for sale anyway.

Just looking at cartridges of the world there were at least 18 in the 7th edition from 1968 and this pre-dates the 260 Rem. 6.5 Rem and at least a dozen more not counting the less mainstream wildcats. So well over 30 is best guess.

Just looking at cartridges of the world there were at least 18 in the 7th edition from 1968 and this pre-dates the 260 Rem. 6.5 Rem and at least a dozen more not counting the less mainstream wildcats. So well over 30 is best guess.

Those water capacity numbers look like to the neck so with a bullet seated the Weatherby may be closer to the 264 or at least the short chambered ones.

It depends on where they take their info from. The Hornady reloading manual lists 2700 for a 140 out of the 6.5x284. Nosler lists 2953. Of course WBY is going to take info that makes their product look better. My .264 WM easily gets 3100 and WBY numbers show 2929 even though factory loads are rated to be better than that.

I'll bet that Weatherby ammunition is going to be $70/box too. I'll stick with $33/box 6.5 PRC.

Yep, $65 on their site for the accubond.
Still wondering about the actual case capacity. The screengrab Whelen posted from the shooting times article is all over the place with it’s purported capacities for known cartridges.

I'm wondering how the 145 gr eldx hornady cartridge in 270 WSM at a listed 3100 fps would compare.

The 6.5 WBY RPM is running higher pressures is my understanding

Still waiting to hear an independent verification of the case capacity. That shooting times table is all kinds of fubar.

ELD-X is down 34,2 inches @ 500 with a 200 yard zero. Maximum point blank range 300 yds at 3.9" of drop.
Just about identical to the 6.5 143 gr ELD-X if the 3,045 fps is do able with handloads. It might be a custom burn rate powder more like the light magnum loads so hard to do with canister powders, but I don;t know if this is the case. Anyway now I don't have to rush out and get one. But a titanium 257 WBY would float my boat if the price ever drops.
Mostly the cool factor as the titanium is less than one beers worth of weight lighter.

Just an FYI for anyone considering this cartridge.


Ammo is available for $41 and change here:
https://www.budsgunshop.com/product_info.php/products_id/713087936

I recently bought 6 boxes of the 127lrx for $35.96/box from wholesalehunter.com

Accurate Arms and Ammo have 1 more Redding 3 die set in stock after I ordered a set for $140 and change delivered. Redding is releasing the dies mainstream Feb 1st.

I’m awaiting Weatherby’s new Backcountry model from the custom shop with a deliver date of March 12th. Hope it’s a shooter.

AKwolverine,

"Still waiting to hear an independent verification of the case capacity. That shooting times table is all kinds of fubar."

Yep. Measuring case capacity by filling the case to the mouth is not the functional capacity. If it was, the .30-40 Krag's very long neck would count as "extra" powder space, even though with most bullets the neck is filled with, well, the bullet--not powder. You could shorten the neck 1/4" and it wouldn't make any difference in functional powder room.

On the other hand, the Weatherby fills yet another slot in the ever-increasing number of 6.5mm rounds.

As I have a Winchester Model 70 that needs a barrel and has a standard .473 bolt face this is another interesting proposition. wonder what the barrel life will be? The 6.5x284 has a reputation as being a bit hard when pushed. Another over bore 6.5?

The 6.5/.284 has a shoulder angle and short neck that tend to direct how powder gas right into the throat, just in front of the case mouth.

Case capacity is not the only factor in throat erosion.

OK, understand that. Will the Weatherby 6.5 RPM be a better choice? The three I am looking at are the 6.5X284, (many options, and not sure of the differences. Norma, Lapua etc. ) 6.5-06, and now the 6.5 RPM ?

well anyway my 6.5x284 shoot round 2850 fps and shoot very nice 5 shot groups even the stock Savage S.S. shoots 2850 fps and shoots 5 shot in little groups. i do like the 6.5 x 284 for longer target shooting but i still kinda like my Winchester pre64 264 WIN. Mag.s . if i was to buy a new cartridge it would be 26 Nosler, worried about erosion ? buy a cartridge that shoots slow its that simple

The 26 isn't nearly as bad on barrels as some apparently believe. Generally they last at least 1000 rounds, which is a lot more than the average hunter shoots from a hunting rifle.

That'a right. Once loads are worked up, as a hunter, no reason to keep on blasting. My 26 Nos does show thru the Hawkeye, the effects of 400 rounds, but is still a sub MOA shooter.

My 6.5-284 with even more rounds shows some erosion, but also remains a sub MOA shooter.

If I'm pushing 140 VLD's at 3K with RL-17 out of my 6.5-284 and I know some of the .264 guys post much better speeds than we've seen mentioned here,.

I'm waiting to see what "Fire" speeds we're gonna see out of the RPM and PRC...

Ya can't believe those books....

DF

Most of the guys worried about barrel life havent worn out a barrel. That and they make barrels every day.

Waiting for some first hand accounts of the rpm ... rifles and ammo appear to be available.

I picked up a box of Weatherby 6.5 RPM 140gr AB ammo, and yes its just an extended 6.5-284, I pulled the bullet and got 64.6grs of powder, looks like/similar R23 but not positive.

I got 80.1grs of H2o, the loaded length was 3.333", here's a cpl pictures for comparison,

6.5-284 / 6.5 RPM / 280AI






6.5-284 / 6.5 RPM / 280AI / empty 6.5 RPM

Is the rim of the RPM rebated? It doesn't look like it from the photos.

Rebated......

6.5 WBY RPM (Rebated Precision Magnum)

Weatherby has traditionally designed and built ultra-high velocity cartridges with unique case designs-belted magnums with a double-radius shoulder. This is seen in all of the existing Weatherby cartridges until now. The Mark V 6 lug standard action has been one of our best-kept secrets for years. The goal of the 6.5 WBY RPM (Rebated Precision Magnum) was initially based around maximizing the potential of this great lightweight action. Setting out to produce the best backcountry rifle and cartridge combination ever, it was a project not taken lightly. At our core, Weatherby prides itself in ballistic superiority. The rebated rim helps achieve the desired velocity and energy we were looking for while remaining compatable with our 6 lug action. The 6.5 WBY RPM packs a punch and is capable of being chambered in Weatherby’s new sub five pound rifle, the Mark V Backcountry Ti. This combination offers maximum downrange performance in the lightest rifle possible. After years of development, the 6.5 WBY RPM combination achieves the weight savings, ballistic performance and price that cannot be found in a rifle anywhere else.


THE CARTRIDGE

The 6.5 WBY RPM is based on a lengthened version of the existing 284 Winchester. This cartridge has a rebated rim, making it compatible with standard 30-06 bolt faces and reloading equipment. However, the large body diameter, low body taper, and 35-degree shoulder mean that case capacity is greatly increased, leading to higher velocities. In addition, bullet innovation in the 6.5mm category are highly efficient with less drop and wind deflection than many heavier calibers. All these details culminate into a cartridge that delivers 1,500 foot pounds of energy at 500 yards capable of ethically taking big game animals across the globe.

Pretty easy to get a 264 win over 3100 with a 140, even with a standard chamber. Mine shot great with 140 accubonds @ 3150 with reloder 22.

Hmm,a 6.5X280AI would look interesting.

Doh! and I thought RPM was revolutions per minute. Interesting cartridge and package I hope other makers pick it up. Seems like some long range target shooters would experiment with it. You could run it at 6.5x284 velocities and maybe get longer barrel life due to lower pressures and longer neck. In fact I think this could be the best niche for this cartridge.

Bccp,
Thanks for posting.
I think it may make for a nice option for a LA 6.5; hopefully some of the other ammo makers will pick up the chambering.
I could like a brown pounder adl, LA ti action, 8 twist rock #2, and TT special at a little over 5 pounds ....
Or just buy the weatherby offering - but what fun would that be!

Wby store shows brass available at around $1.5 a case.

I would always get a commercial offering over a wildcat.

It should feed much better than a PRC.

I like the 7mm rpm version better.

The MkV Backcountry Ti is reportedly 4.8#'s. That's too light for my tastes. The steel version is 5.3#'s.

Those would be a good bit cheaper than what you're thinking and as hard as ultralight rifles are to shoot, would probably be about as accurate.

Maybe not as much fun....

DF