These gains assume the rifle is barreled with the stellar Bartlein 5R gain twist
A gain twist
barrel engraves and spins the bullet up gradually.
By this time Bartlein was also offering gain twist
The benefit of gain twist
in an extreme high-pressure/high-velocity modern revolver like the M460XVR is similar in that it allows the bullet to transition into the rifling more slowly from a nonrotating state instead of being forced to "spin up" instantly when it crosses the barrel/cylinder gap and slams into the rear of the barrel at the very instant deformation potential is at its height.
One of the intriguing aspects of the trials was that the Commission had decided to use a gain twist
barrel to over-come the effects of throat erosion.
barrels beginning with a slow twist and incrementally increasing toward the muzzle should last longer than barrels with uniform fast twists.
Though this goes into theories of why gain twist
barrels seem to shoot so well, I did not cover gain twist
That, coupled with my gain twist
barrel design, allows me to hit my target muzzle velocity of 2,600 fps with Berger 90 grain boat tails and stay strong supersonic (1,249 fps remaining) out to 1000 yards.
I am loading the same powder charges in my gain twist
To get those long, heavy bullets moving out of the throat faster you may want a gain twist
I am working with Bartlein on a gain twist
that begins with 1:13" at the chamber and doubles to the muzzle where it hits a final 1:6.
seems to be helping with longevity a lot.