I saw a 6mm/284 Win at the range last night. Looked like a hot little number. Can anybody give me the particulars on this cartridge? I know it is a 284 Winchester necked down the 6mm, but what type of velocity is attainable in a 26" barrel?

Ballistically, the 6mm-284 (and the 6mm-06, which are pretty darn close) will equal a 240 Wby. So, basically, a 100 gr bullet at about 3200-3300 fps. - Dan

I have built and tested one with peak strain measurements and chronograph. You can get about 100fps more than a 6mm rem within safe pressures(Adam Bennett barrel). Not as impressive as I had hoped. Maybe I'll try again with a better barrel.

I have been shooting 6mm Rem varmint and target rifles for over 20 years. It has always been one of my favorite small bore cartridges. I started playing with a 6mm-284 30" Krieger about 6 years ago. I saw a little more gain in performance than grkldoc reports, however, there is not a significant increase in velocity to get too worked up over. Throw into account that brass and dies are very hard to find - you generally neck your own brass and cut your own dies. It is a lot of work for a little bit of improvement. In addition, you can easily get a 6mm Rem to feed from a magazine, however the .284 case is more problematic.

Where I have spent most of my LR target and varmint focus is on the 6.5-284. Shooting a high BC 140gr bullet is a wonderful thing at 600 and 1000 yards. This cartridge is a step up in performance over the 6mm Rem for LR work.

In my opinion, you can get a 6mm Rem to shoot just as accurately as a 6mm-284. If a 100+fps is important to you, then consider the larger case. Otherwise, the 6mm Rem is a great cartridge.

I built a 6/.284 in 1964 with a 1/10" twist, 26" Douglas Premim Grade bullet and throated to shoot the 105 Speer spitzer seated to the base of the neck. It was barrelled and chambered by Shebal's Gun Shop in Fairbanks, AK, and stocked by Fagen's using AAA grade Myrtlewood. This is the only rifle I've ever owned that consistently shoots five shots through the same ragged hole at 100 yards, and it has never changed zero (despite what you hear about Myrtlewood!!). It produces 3400 FPS with the Sierra 100 grain bullet, and will beat 3500 with the 85 grain Sierra HPBT and Hornady 87 grainer. For a deer load, I use the 95 grain Nosler at 3350 FPS. It is a real killer, and I find it to be a big step ahead of the .243 Win., but not too much better than the 6mm Remington. It is also harder on barrels, but I like it anyway!!