back in the 90's I did a bunch of load development for the 8mm RM
I ended up using Reloder 22 exclusively for much of my handloads as it had over 100% load density and filled the case right up to the base of the bullet, which is conducive for high velocity accurate loads....
the most accurate load I developed was with the 200 gr. Swift A-Frame and 82 gr. of RL22 velocity was 3050 fps, Fed. 215M primers
another good load was the 200 gr Barnes XFB bullet with 80 gr of RL22 at 3000 fps, Fed 215M primers, this was my Kodiak deer load in bear infested areas,
another excellent bullet is the Hornady (#3238) 220 Gr Spire Point with a .464 bc and .301 sd.....loaded with 80 gr of RL 22 at 2900 fps.......... but is not listed in the new Hornady 2012 9th Edition manual, or their website.....apparently this bullet has been discontinued, too bad as it offered the best performance in the 8Mag, I still have 4 (100pc) boxes if anyone is interested...
Hornady now offers a 180 Gr. GMX in 8mm
I did use the Sierra 220 gr Match King with 80 gr. of RL 22 accuracy was stellar but had a really bad scary close range incident with a brown bear that involved numerous shots and a 300 Win Mag backup with 200 gr. X bullets... the SMK bullets did not penetrate enough to dispatch the brown bear and am fully convinced the 300 WM killed the bear with the X bullets, have never used a single Sierra bullet since, it is a good bullet for deer but just not sturdy enough for the brown bastards in Alaska at 20 yards
the new Nosler Manual #7 has data for the no-lead 180 gr E-Tip with a listed bc of .427 and sd of .246 ..the highest velocity is found with RL22... you could probly use this data for the 180 gr.GMX also, just start low and work up
180 gr. E-Tip COAL 3.530"
88.0 gr. 3283 Fps max load
86.0 gr. 3242 Fps
84.0 gr. 3181 Fps
heres an excellent article I found .....
The 8mm RM doesn't take a back seat to many cartridges when it comes to raw game-stopping power, and muzzle energies approaching 4,000 ft-lbs were achieved with most of our loads.
The M700's magazine length of 3.7 inches allows considerable flexibility in seating depth, and a little experimentation revealed that this particular rifle liked to give the bullets a running start to the rifling. Thus, all bullets were seated .030 inch off the lands, except for the Barnes Triple Shock-X and Swift A-Frames, which were loaded .050 inch off, as recommended by their makers.
Barnes TS-X bullets offer the hunter a no-lead alternative and provide deep penetration and controlled expansion. With the 180-grain version, a load of 85.0 grains of H-1000 produced a sizzling 3,025 fps and grouped 1.34 inches. The same charge weight of MagPro zipped this bullet along at 3,051 fps, and it still shot under two inches. In addition to MagPro, the 200-grain TS-X liked Reloder 25. With 84.0 grains, velocity was only one lone foot-pound shy of 3,000, and groups averaged 1.57 inches.
A "best of show" load was the Hornady 195-grain InterLock over 84.0 grains of Reloder 25. It consistently averaged less than an inch at a sizzling 2,936 fps.
Nosler offers three 8mm bullets that excel in the 8mm RM. A terrific load with the 180-grain Ballistic Tip is with H-4831SC, which grouped under an inch at 2,979 fps. The 200-grain Nosler Partition was boosted along at 2,950 fps by 85.0 grains of H-1000. Also of note is the new 200-grain AccuBond over 85.0 grains of MagPro at 2,970 fps.
For what Jack O'Conner called a "Sunday go-to-meetin' load," check out the 220-grain bullets. Sierra's 220-grain SBT's thick jacket will stand up to the 8mm RM's velocity, and it shot into an inch and a half with 83.0 grains of H-1000. The highest muzzle energy of any load was with the ultra-tough 220-grain Swift A-Frame. Pushed by 82.0 grains of Reloder 25 at 2,963 fps, it had muzzle energy of a crushing 4,290 ft-lbs--enough for anything in North America.
A good moderate load is the Speer 170-grain Semi-Spitzer with 55.0 grains of H-4895 at a leisurely 2,597 fps. This mimics the 8x57 Mauser and makes a terrific low-recoil load for deer.
The 8mm Remington Magnum can hold its own anywhere. Unfortunately, it will probably continue its fade into obscurity. Nevertheless, the hunter armed with one is well prepared, especially with handloads created with today's high-tech bullets and ultra-slow powders.
website found here......