Getting ready to start soon on this as I'm waiting for my VVCG barrel to be made. Any and all advice needed so as to go smoothly while necking down. I have a Redding set which includes F/L sizer, seater, and form/trim die. Please advise. Thanks, Jeff

I neck-size mine down in a RCBS .25/.284 trim die, run them through the regular 6mm/.284 FL die, then load 'em up!! Never had a problem of any kind... (I use RCBS dies, but yours should be at least as good!!)

eldeguello is right. Try the RCBS case forming die. If you try to form from 284 to 244 you will probably crush the cases during forming. When I chambered my rifle in 6-284, I made the chamber a little tight. Depending whether you gunsmith or if your doing it yourself, your chamber might be tight enought when you close the bolt it might be a little tight going down. Once you fire form you won't have a problem. But remember to keep plenty of grease on your bolt lugs or they could possibly gauld. Then you have a slight problem. You can also help prevent this by purchasing a set of Redding competition shell holder set. Good luck. It is a great caliber. I love it and I made a great shot on a prairie dog at 1440 yards last year with a 107 grain Sierra.

I could not size the necks from .284 to 6mm in one operation, ended up using a 5/16" collet in a South Bend lathe to reduce the neck size before putting the cases in the 6mm-284 die. The gunsmith who rechambered the rifle thought the lines on the neck from the collet might reduce the case life, but it hasn't worked out that way. I also use the lathe to trim case lengths.

Tom

JB, did you say you were forming using 284 brass? If so, why not use 6.5-284 brass as a starting point? - less to form - plus you can get it from Lapua and others.

JB,
I use the same process as Eldeguello and have not had a problem. You can reach out and touch coyotes with 70 gr BT's. One note, my form/trim die is 25/284 RCBS and my FL Sizing Die and Seating Die are Redding. Both work great, also the 6mm Rem guys will say they can match anything a 6mm/284 will do. They can but have to use a pry bar to open the bolt. You will be able to better their velocities 100-200 fps and load your brass 10-12 times.

Saludos...Frank

Griongo is right. The 6mm/.284 is the equal of the .240 Weatherby Magnum. Mine will fire the 105 Speer in excess of 3300 fps, and will approach 3600 with Norma MRP and the 85 grain Sierra. One 85-grain Sierra/MRP load I tried gave 3623 FPS, but was not as accurate as a lighter one that averaged 3584 FPS. This latter load gave no indications of high pressures IN MY RIFLE, and produced .5 MOA!! My rifle has a 26" barrel, 1/10 twist, and is throated for the 105 Speer seated to the base of the neck. So, in effect, it has some "free-bore". This factor probably allows me to use loads that would be too much for a standard chamber.

Thanks for all the info. On your advice, I've ordered a .25-.284 form/trim die to help squeezing the neck down. Can't wait to see what kind of speed I can get out of the 12" barrel with a 1-10 twist.