After may years of looking I finally found a reasonably priced M600 6.5 to go with my M600 .350 RM.
I have found quite a bit of loading data but none includes my favorite powder... WW748. It works great in all the centerfire rifles I own in .223, .308, .350 RM and .405 Winchester. Now the question is will it work in a 6.5 RM?
Any load data you may want to share with this or any other powder would be appreciated.

Bob

While WW 748 is a splendid powder for your other calibers, it is somewhat too fast for your new 6.5 Remington Mag.

If you like the WW powder line, WW 760 is a good fit for the 6.5. When I was loading for a 6.5 many years ago (Ruger 77, and no, I should never have sold it), I used H4831 very successfully under a 120 grain bullet. IMR 4350, 4831, N-160, H-414, RL 19 and 22 and other powders in this burning range are the appropriate powders for your 6.5 mag.

There's a wealth of loading data for this cartridge out there; if you can't find it listed as 6.5 Remington Magnum, look at 6.5/284 and 6.5/06 data as they have virtually identical case capacities to the 6.5 Rem Mag. As is prudent with any data, start below the heaviest loads listed and work upward according to pressure indications.

Thankyou for the reply. I just found some of my old reloading manuals that list a lot of loads for many bullets that are not even available any longer. The fastest powder listed for the 6.5 is IMR3031 which is a lot faster buring than WW748. According the the powder burning rate chart I have WW748 and IMR4320 have about the same buring rate. It is also one of the better powders listed the manuals. Seems IMR 4350 is the best overall. Guess it won't hurt to try it....lets hope not at least.
I am in a minor quandry however. All the loading data I have seen complains that long bullets take up too much powder space in the 6.5.....ok then why are there no compressed loads showing in any of the manuals but there are lots of compressed loads for the .260 Remington....? Operating pressure for the .260 is 60K psi...the 6.5 52K. Velocities are shot with either a 18.5" or 22" barrel in the 6.5 but a 24 or 26" barrel in the .260.
Did you have a chronograph at the time? If you did what real world velocities were you getting?
Any thought for a bullet for deer/black bear.... 120 Speer, 100 or 125 grain Nosler Petition, 129 Hornady Spire Point or SST. The SST would really be nice at 2900 fps but I am not sure if it will seat that deep without getting the neck above the bearing surface of the bullet.
A 120 grain 6.5 has the same SD as a 165 .308 and a 225 .358 which is also what I shoot. They also have about the same BC as those bullets if the design is the same or close. If I could get 2900 fps from anyone of the above bullets in the 120-130 grain class I would be very happy.

Bob

RJM: I still have a box of 20 6.5's that I loaded waaaaay back when. I know that they're loaded with 120 Sierras and orginal surplus 4831 (just a tad slower than currently manufactured 4831). But I have misplaced my notes and don't recall just exactly how much powder.

I've had a chronograph almost since Dr. Oehler introduced his first Model 10, and I did chronograph those loads. Again, I don't have any records (and no gun to shoot them in currently), but my recollection is that the 120's were running about the same velocity as 140's from my .264 Winchester, which was around 3100 fps. I don't think you'll have any trouble at all in getting 2900+ from your carbine barrel.

I have a copy of Ken Waters Pet Loads that lists some good prospects for the 6.5. He lists 55.0 grains of 4350 from a 20" barrel at 3001 fps and calls it a "factory equivalent load". He doesn't list WW 748 (or its spec equivalents, BL-C2 or WC-846), but does list 47 grains of 4064 as yielding 2860 fps with the 120 Sierra. A note of caution: Although WW 748 is usually listed as slightly slower than 4064, they have somewhat different burning characteristics. I like 748 in small .22 centerfire cases, and use it very satisfactorily in medium bore cases like .30-30, .300 Savage, and .308. But all my experience with larger-cased, smaller bore cartridges indicates that 748 can get a little "horsey" and not behave like you would like. If you decide to give the 748 a try, just be conservative with it until you can prove it out.

Waters also lists 55 grains of 4350 with a 125 grain Nosler Partition at 2985.

I recall shooting one coyote and one deer with my 6.5 and 120 Sierras. Both were one-shot kills, but that's not a very large sample.

I would be confident in deer hunting with any of the 120's or the 125 partition. Waters loaded his 6.5's to 2.84" for a Ruger magazine, but you'll probably need to get your LOA down to about 2.75" or maybe 2.8" for the Remington magazine. I don't think any of the 120's (except maybe the longer BAllistic Tip) should require excessively deep seating at this length. Waters loaded 140 Sierra Boattails (55gr H4831, 2815 FPS) and 140 Nosler partitions (52gr 4350, 2798 FPS) in his article, and notes no problem with seating depth.

By the way, the SAAMI pressure standard for the .260 Rem is expressed in PSI (measured by piezo-electric methods), and for the 6.5 Rem is expressed in CUP (copper units pressure), measured by the older copper crusher method. The two methods cannot be perfectly correlated, but 52K copper and 60K PSI are very roughly the same.

Good luck with your find!

Bob,
Congrats on your new 6.5. I used to have a 264 Win Mag. After blowing a few Texas deer in half with 120 grain Sierras I started using 140 grain bullets. In your 6.5 I would use the 125 Nosler Partition for my all round load, maybe switiching to a 140 or 160 grain for Black Bear over bait of hogs up close.... but that is what the 350 Mag is for.