RETUMBO powder

[CZ2506]

Does anyone have any experience using Hodgdon RETUMBO powder in a 25-06? I using 117 gr Hornady SST's. I use H4831 and have been thinking about trying either 4831sc for better metering or the RETUMBO to fill up the case. I'd appreciate any imput.

First off I have never used it in an 06 case. But I can see a problem using such a slow powder in an 06 case. You might actaully loose velocity. Cause you can't get enough powder in it. Let us know if itworks.

[CZ2506]

Hodgdon says you can squeeze 60grs into an 06 case, but it will be a compressed load. estimated velocity 3050fps.

One more question if you don't mind. We talk about muzzle velocity and downrange velocity all the time, but I never hear anything about the acceleration rate of the bullet down the barrel. The acceleration rate must have at least as much to do with putting rotation on the bullet as muzzle velocity, so why can't I find any info?

[driftrider]

The initial rotation rate of the bullet depends entirely on the muzzle velocity and the twist rate of the barrel. For instance, if you have a rifle with a 1-turn-in-12" twist, and the muzzle velocity is 3000fps, then the rotation rate is 3000 R/sec, or 180,000 RPM. If the twist rate was 1-in-10", at the same 3,000fps MV, the rotational rate would be 3600 R/sec, or 216,000 RPM. After leaving the muzzle the velocity and spin rate become independant, and I've never seen any data regarding the rate at which the rotational speed slows over time after leaving the muzzle. I would guess that the rotation speed sustains better than velocity because of the small amount of drag the bullet would encounter that would resist the spin, but that's purely speculation.

Mike