Re: 6.5 RUM
Richard offers an extensive line of 6.5mm bullets up to and including a huge 169.5 gr ULD RBBT. Other then that there is a 120, 125, 130, 135, 142, 150, 160 and 165 gr. All offered with either a 10 or ULD ogive and either Flat base or RBBT.
He also offers the same bullets from 120 to 160 in his flat based Bonded Core hunting bullets.
As far as velocity goes, it depends on who you talk to and what they are shooting. I have talked with guys that are loading the 264 Win Mag up hot enough to match my 6.5mm Allen Xpress [img]/ubbthreads/images/graemlins/blush.gif[/img]!!
Still on average, I would list the common 6.5mm rounds as follows with a 142 class bullet in a 28" barrel.
6.5-06 AI......3050 fps
6.5 WSM........3100 fps
264 Win Mag....3200 fps
6.5-300 Win....3250 fps
6.5 STW........3350 fps
6.5 AX.........3350 fps
6.5 AM.........3475 fps
These are of course general numbers. Anyone can load up any of these rounds to jump several spots in this order but using relatively sane chamber pressures in all I feel this is a realistic velocity representation for the rounds listed.
The 6.5/7mm RUM should be nearly identical to my slightly shorter 6.5 Allen Mag as they have nearly identical case capacity.
In my opinion, as you go up in case capacity with this caliber and the 257 for that matter, you really need to start adding on the bullet weight to see the advantage of the larger case capacity. I have not done alot of testing with the 6.5mm AM, at least not nearly as much as my 257 version but I can tell you with the 257 AM, unless your shooting a bullet of 130 gr or more, your really better off with an STW class round.
That said, if you pour on the bullet weight and use the 156 gr ULD RBBT, the larger case capacity starts to pull more of an advantage, a full 175 to 200 fps over the long belted magnum wildcat.
I see no reason why the 6.5mm rounds would be any different.
For a comp rifle, I would personally never go over the size of say a 6.5 WSM or 264 Win Mag and use bullets in the 140 to 150 gr class.
Just my opinion!!
Allen Precision Shooting
Home of the Allen Magnum, Allen Xpress and Allen Tactical Wildcats and the Painkiller Muzzle brakes.
Farther, Faster and Flatter then ever before.
Web Page: www.apsrifles.com