284 Shehane
Rob:
I had 6.5x284 Shehane dies from my BR days and thought I could just switch the bushings, but that will not work. My dies are by Jim Carstensen and are his typical high quality.
On 6mmBR.com, on the 7mm info page, there is a reamer print for Mark King. John Whidden does most of my chamberings and keeps my reamers at his place.
I always thought the 6.5x284 was a little too much of a good thing for a 6.5 chambering, but in 7mm it is just about perfect. I have shot the 284 Shehane for the last two seasons and I can think of nothing that can match up, all things considered, from accuracy to recoil management to high BC bullets, to long barrel life, and Lapua brass.
If I was not shooting this 7mm I would shoot a 300 WSM. Great barrel life and accuracy but not as good if I miss a wind call. In 1000 BR where most make runs of 30 to 60 seconds in heavy gun, I think the 300 WSM is great, but on 20 minute strings in the prone game, the 284 Shehane will give you a target ring of buffer over the 300 WSM and 300 Win Mag and that means higher scores and a better X count. I have seen this time and time again. My problem is that some of the seasoned prone shooters can read the wind like a book. You just cannot believe what shooters like John Whidden, Mid Tompkins, Kent Reeve, Norm Crawford and some of the Palma Team members can do in the wind. I am learning and have my days from time to time.
The reason I bring this up this chambering is that in 1000 BR we never have a real chance to compare wind drifts because we have no feed back from shot to shot. You can have a great run and have crap for a score and/or group. On the other hand, you can do everything wrong and win the relay or shoot off. It is hard to figure it out because the only feed back you get is the finished target.
In long range prone, we get to see the result on each and every shot. We also get to look at other targets on the line through our spoting scopes in an effort to pick up on how conditions are blowing the bullets of our competitors.
Charles Ballard has run tests at 1000 yards with his 284, a 6.5 and a 300. His straight 284 shot inside of each one. The 284 Shehane has about 3.35 grains of H20 capacity over the straight 284 -- and I run about 3 grains more H4831SC than Charles with a corresponding increase in fps with accuracy without pushing the load.
Another point about the 284 chambering is that less taper in the body helps you on a fast run in the BR game and keeps you from having hard bolt lift in the prone game which helps you maintain your position if you keep the gun in your shoulder the entire string. Of course, in F-Class that would mean less bag disturbance just like BR. Additionally, since you are basically expanding the body with less taper, but leaving the shoulder alone, you don't suffer an even shorter sucked in neck after fire forming like you would if you AI the chambering.
The 284 Shehane is nothing but a sweet 100 yard cartridge that even shoots well during fire forming. You might think about trying it out. I hope this information helps you and others just a little in making a chambering decision for 1000 yards.
Favor center,
Jim Hardy