Why does the Gallager Rapine mould work?

[Bruce Cobb 1723V]

I am restarting this thread again because the original is now all morphed up. " The barrel slugs to about .523. I know the Rapine bullet is .540." This works very well because of its ogive design. This is the radius near the front of the bullet to its maximum diameter. Since the largest diameter of .540 and is so short and narrow, it deforms into the rifling and creates a great bearing surface. Again, it is not always about size.

[Jud96]

I am restarting this thread again because the original is now all morphed up. " The barrel slugs to about .523. I know the Rapine bullet is .540." This works very well because of its ogive design. This is the radius near the front of the bullet to its maximum diameter. Since the largest diameter of .540 and is so short and narrow, it deforms into the rifling and creates a great bearing surface. Again, it is not always about size.

Anything that is .017 over size will deform into the rifling. It doesn't matter what the ogive is, the ogive doesn't touch the rifling at all, only the bearing surface, only the small driving band on the Rapine 540300 engages the rifling. The nose of the bullet and the heel are both under .540 diameter and are designed to not touch the rifling but they may in his .523 bore because of how over sized the bullet is. You have to take bore size into account, just because a .540 diameter bullet will shoot out of a .523 bore doesn't necessarily mean its the best idea, this can cause high pressures and that is a lot of lead to squeeze down and stretch out.

[Bruce Cobb 1723V]

Yes, the driving band is short and narrow and just above the ogive in this design.

[Jud96]

Yes, the driving band is short and narrow and just above the ogive in this design.

The driving band is below the ogive just like the bearing surface on any bullet.

[Owen F]

My problem is not with the rifling or the bullet gripping it. It's that the Moose bullet sticks out of the cartridge too damn far. I can't even get my Gallager to close with the Moose bullet. My teammates cartridges with the Rapine bullets fit fine and I can close up the gun.

I'm going to head over to a machinist I know today and see what he'd charge me to make a bullet mould based on the Poultney and Trimble.

[John Holland]

Owen - All of the modern Gallager cases I have seen have a shoulder inside the case. If you increase the depth of the shoulder then the bullet will seat deeper into the case, thereby allowing you to close the action. This work will also require the services of a Machinist. The original Gallager cases were only thin brass foil, or foil with a paper wrapper. They were not the thick walled cases of today.

[Owen F]

Owen - All of the modern Gallager cases I have seen have a shoulder inside the case. If you increase the depth of the shoulder then the bullet will seat deeper into the case, thereby allowing you to close the action. This work will also require the services of a Machinist. The original Gallager cases were only thin brass foil, or foil with a paper wrapper. They were not the thick walled cases of today.

I'm aware of the shoulder inside the case, but the bullet is stopping well before that. It's hitting the lower driving band on the bullet well before the bullet gets to the shoulder inside the case. The Moose bullet is just designed wrong for an original Gallager. The Rapine bullet sits further in the case and will chamber fine.

[John Holland]

Thank you, now I understand your dilemma!

[Bruce Cobb 1723V]

The driving band is below the ogive just like the bearing surface on any bullet.

I don't believe you are correct with the above statement concerning this design and other lead bullet designs. I think you got things twisted around. The driving band on this design is a larger diameter and not below any of the smaller diameters associated with the ogive radius. The whole purpose of driving band is to engage the grooves in the barrel which have a larger diameter than the lands. Lead bullets often have more than one driving band. BTW, the most accurate modern made bullets ( boat tails ) don't have a driving band at all and DO use the largest ogive diameters on the radius to replace the driving band which engages the barrels grooves.

[Jud96]

I don't believe you are correct with the above statement concerning this design and other lead bullet designs. I think you got things twisted around. The driving band on this design is a larger diameter and not below any of the smaller diameters associated with the ogive radius. The whole purpose of driving band is to engage the grooves in the barrel which have a larger diameter than the lands. Lead bullets often have more than one driving band. BTW, the most accurate modern made bullets ( boat tails ) don't have a driving band at all and DO use the largest ogive diameters on the radius to replace the driving band which engages the barrels grooves.

Yes I understand this, I shoot high power rifles probably more than my skirmish guns. The driving band is the bearing surface on this bullet, and the bearing surface sits directly below the ogive. And there are modern rifle bullets with driving bands Cutting Edge makes them. The driving band acts like any other bearing surface. 25mm Bradley guns fire a depleted uranium projectile with a copper driving band, they are still used today. The driving band sits below the ogive. From top to bottom it goes meplat, ogive, bearing surface, lube groove and then the base. The driving band is in the middle of the slug, correct? So that means something is above it and that is the ogive. Whether the bearing surface is .54cal such as the Gallager and the ogive is .50cal the bearing surface still sits below the ogive. I think you are confused on what I was saying, I am not saying the bearing surface is below the surface of the ogive and is smaller in diameter, I am saying the ogive tapers down and then abruptly meets the driving band. Whether the bullet has a secant ogive like a modern high BC bullet or is a Gallager bullet with a driving band, the ogive is above the bearing surface in relation to its location on the projectile from top to bottom.

[Bruce Cobb 1723V]

Yes, I guess we were just saying the same thing differently.