| Rule303 |
| (.416 member) |
| 12/01/23 08:21 AM |
Re: Is the 7mm Rem Mag slow and never achieved predictions?
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Quote:Quote:
The original claim for short fat cartridges being more efficient was based on the clam that the Primer flame would ignite a greater percentage of the powder. True or not I do not know. What I do know is that if this is true then different powders will most likely be required. Probably slower powders for the same calibre and bullet.
I know one bloke who is getting damn near 358 Norma Mag velocities out of his 35 Whelen using a new powder. I do know that long throating a chamber and seating the bullets out a bit does increase the Muzzle Velocity. Roy Weatherby knew a thing or two.
The last increases case volume so more powder can be used.
Some guys just always seem to get higher velocities as well.
True, but even if you use the same amount of powder there is a velocity increase when long throated. Is it enough to make any real world difference, I'd say not. Long throating comes handy when using mono mental bullets as you do not have to seat them down into the powder space.
My Rem 700 as a 270 would barely make 2900fps with a 130 grain bullet. Same load in my Styer Prohunter gives me 3200fps. So, yes, the barrel can make a difference. I now use 140 grain 270 bullets and these chrony at 3100fps.