6mmAI or 6mm-284?

[AndyW]

I currently have a 6mm Remington based on the Remington VSF platform that has been customized, a short action. I am considering going the Ackley route with the 6mmAI or 6mm-284. I am thinking of the latter because the case is somewhat shorter and that should give me more flexability with bullet selection. As well I will only have to neck down the Lapua brass and shoot. Right now I am shooting the 87 grain Vmax out of the 6mm and getting 3450 FPS. I like this bullet, so would be mostly using it which ever route I go.
Anyone shooting either of my above options?
What kind of velocity and accuracy are you getting with the 87 Vmax out of either?
Any problems with the short action with either case?

FYI- I currently have a 6mmbr on the exact same platform, shoots lights out, easy on barrel, etc... It is my go to vermin gun. I believe the 6mmbr is the most accurate 6mm, and mine stands up to this reputation. Now I want the fastest 6mm,within reason) and I believe the 6mm-284 is the caliber, but it has to be done out of a short repeater action.

 

[Tommie]

The difference in case length between the 6MM Rem and the 6-284 is only .063" so I don't know how much that factor should weigh into your final decision.

According to Volume 7 of the Hornady loading manual, there really isn't a huge velocity gap between the .243 Winchester, 6MM Remington and the 6MM-284. Matter of fact, the .240 Weatherby and .243 WSSM aren't much ahead of the others. From the smallest to the largest, we're only looking at a 200 FPS spread.

How much throat erosion are you prepared to accept for an extra 100 FPS?

Tom

 

[AndyW]

Looking throught the Sierra manual I was suprised to see that there is really no velocity difference between the 6mm-284 and the 6mmAI?

 

[Tommie]

Andy,

Once optimum bore capacity is passed, the law of diminishing returns kicks in swiftly. Most people agree that the lowly .243 Winchester has near-max practical capacity for the 6mm bore. Any increases in powder capacity yield very minimal velocity gains. Instead of looking for increased capacity, you might think about better utilization of what you already have. Build a 6mm Rem with a 28",or longer) barrel. You'll be amazed at the velocities you'll hit. For example: my 6x250AI has a 27.5" barrel and shoots an 87gr v-max at the same speed as my 6mm Remington with a 24" barrel.

Tom