
09-15-2002, 08:30 AM
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Beartooth Regular
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Join Date: Sep 2002
Location: Afton, VA
Posts: 551
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Gentlemen -
Thanks for the fast response. The Remington "Accellerator" ammo was to my knowledge the only high velocity sabot ammo ever offered to civilians.
I will look in SN for the .30/.22 sabots, as they might be useful for some types of testing.
The problem with the Rem ammo was that the 50 gr bullet in a .308 bore imposed burn rates on the powder that can't be resolved my current commercial propellants. These loads (30-30, .308 Win and 30-06) reached at more about 30,000 CUP hence energy was a fraction of the parent round, and velocity variations were high. They really needed a powder that was both fast and insensitive to pressure on burn rate (the new XMP 5744 is a notable exception).
To get full energy potential, we need to use bullet weights at the light end of the spectrum that the parent case normally shoots. Hence my interest in the 300 WSM as a platform for the 100 gr 6MM bullets. With the sabot, these would run 107 to 110 grs for total weight, and should perfrom like the 110 gr bullets in .308 that are available.
The advantage is therefore in the increase in sectional density and BC. SD for the .308 at 110 gr is .166, while for the 6MM at 100 gr it is .242. A 100 gr 6MM at 3800 fps is a whole new ball game in terms of down rage energy and trajectory.
To push that bullet at 3800 fps in a 6MM bore, you would need over 100 grs of high density powderand a 32 inch barrel. The 300 WSM needs only 75 grs to accomplish the same thing with a 110 gr bullet - or 110 gr sabot with 100 gr 6MM bullet.
By extrapolation we could duplicate the velocities of many of the new beltless, overbore ammo offerings with older, smaller cases. A prime candidate is the .338 Win Mag, which has a 1:10 twist rate and will stabilize most .270, 7MM and .308 bullets.
The big market is probably for the .270 and .308 Win, along with the 30-06, using 100 gr 6MM bullets at 3300 - 3500 fps, due to the many rifles out there.
Don't forget that the sabots eliminate the need for a jacket, and do a great job of reaching the lands while centering the bullet in the bore. Coatings for the sabot surface hold limitless possibilities.
I do consulting work on US military ranges, and have seen first hand the M-1 main tank gun fired - it is a 120MM smooth bore with an 80MM projectile encased in a sabot. The 14 lb "dart" does 5250 fps with an accuracy of 1 meter in 4000 meters.
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