joeb33050
01-22-2006, 10:41 AM
Again, for the book, pictures only work on the CBA site, forum, files. Looking for comment, friticism, (yes, friticism, dammit!!), additions, personal stories, lies, what some guy told you, etc. This thing won't let me put it all here, so it's in 2 parts.
There are some situations where the general rules do not work well, as follows:
Some chamber necks are too small to seat a CB of proper diameter for the neck, throat and bore and groove dimensions.
One example is the Browning copy of the Winchester Lever Action rifle in 348 Winchester. John Rhodes has reported on his rifle’s inability to shoot with CB’s. The chamber is made for jacketed bullets of much smaller diameters than needed for CB use.
Other examples include the 41 Colt, 44-40, 38-40 and some transitional rifles such as the Springfield Trap Door.
In these cases there are several alternatives to fix the problem.
Open the throat with a throating reamer.(This should be the LAST choice.)
Breech seat the bullet in front of the case.
Turn case necks or make step-necked cases to allow larger bullets to be used.
Use a "Heel" or "hollow based" design bullet. These are examples of pistol bullets, the information applies to rifle bullets as well.
The 359417 is a conventional design bullet. Sometimes this bullet style, loaded in the case, makes a cartridge that is too big for the chamber. The 386177 is a "heel" style bullet Where the "196 grs" is printed is smaller in diameter than further forward, allowing the bullet to be seated in the case and the cartridge to fit the chamber. The 387178 is a hollow based bullet that, when seated in the case, allows the cartridge to fit in the gun. Upon firing the hollow
base expands, sealing the bore and stopping blow-by and leading.
Use a smaller bullet of soft alloy that makes a cartridge that fits in the chamber. With a fast smokeless powder or black powder the bullet may expand enough on firing to seal the bore.
Military and worn barrel throats present a condition where bullet diameters are needed that are not available in standard moulds. Many factory sporter rifles have such large throats. In this case there are two ways to remedy this:
Have a custom mould made or modify a current mould to fit such a throat, or
Fit the bullet as recommended and use a wad under the bullet that will seal the throat when the round is fired. Such wads are made from paper card and plastics and are cut with an arch punch. with a wad cutter using a drill press, or when a few wads are needed, cut with a cartridge case neck fitted and outside deburred to a knife edge so that cutting is consistent.
Wads can be cut by using a mallet tapped on the cartridge cutter on the wad material backed by a soft backer of wood, leather, or a soft plastic so as not to bend the wad cutter; chucking the cartridge wad cutter in a drill press is a good option.
If using the Lee Collet die to size cartridge necks for loading CB’s, the same die can be used to adjust the cartridge case to cut different diameter wads until the diameter is suitable for the load and chamber throat. Such wads must be at least the diameter of the throat or slightly larger and should fit the cartridge neck under the bullet with no airspace between the wad and bullet and the wad must be seated in the case neck in such a way it cannot fall into the powder space of the cartridge.
In no case should a loaded cartridge neck be larger than the chamber neck; the cartridge may not chamber and even if chambered, dangerous pressure could result. There should be enough clearance to allow the neck to expand on firing. Tight-chambered rifles built for and used by experienced cast bullet reloaders may have very little neck clearance. For the rest of us, the loaded cartridge neck should be a minimum of .002" smaller than the chamber. It is thought that greater neck clearance diminishes accuracy, so a maximum of .006"clearance should be the goal.
Bullets can be sized down in size/lube dies to fit the groove dimensions. Nose diameters cannot be reduced without custom dies. A rather simple die is available from Don Eagan; such dies are made to reduce nose diameters and are also made to taper the entire bullet to fit a tapered throat. Don advertises in The Fouling Shot and can make a die to suit a particular throat. These dies are used in place of the regular size/lube dies in RCBS and Lyman lube/sizers; once all the bullets are modified, the die is removed and the regular die is replaced for seating gas checks and lubing the bullets.
An aside on restricted bores.
Some revolver barrels are squashed where the barrel is screwed into the frame.
Some rifle barrels are squashed where a sight base or sling swivel base is swaged onto the barrel. It has been reported that some Ruger barrels with swaged-on sling swivel bases are squashed.
When the barrel is squashed the bore and groove are squozen smaller, as much as .004"-'005" has been reported. This constriction in the barrel of rifle or revolver may/will substantially reduce accuracy, may be found and measured by slugging the barrel, and may be removed by lapping or fire-lapping the barrel.
There are some situations where the general rules do not work well, as follows:
Some chamber necks are too small to seat a CB of proper diameter for the neck, throat and bore and groove dimensions.
One example is the Browning copy of the Winchester Lever Action rifle in 348 Winchester. John Rhodes has reported on his rifle’s inability to shoot with CB’s. The chamber is made for jacketed bullets of much smaller diameters than needed for CB use.
Other examples include the 41 Colt, 44-40, 38-40 and some transitional rifles such as the Springfield Trap Door.
In these cases there are several alternatives to fix the problem.
Open the throat with a throating reamer.(This should be the LAST choice.)
Breech seat the bullet in front of the case.
Turn case necks or make step-necked cases to allow larger bullets to be used.
Use a "Heel" or "hollow based" design bullet. These are examples of pistol bullets, the information applies to rifle bullets as well.
The 359417 is a conventional design bullet. Sometimes this bullet style, loaded in the case, makes a cartridge that is too big for the chamber. The 386177 is a "heel" style bullet Where the "196 grs" is printed is smaller in diameter than further forward, allowing the bullet to be seated in the case and the cartridge to fit the chamber. The 387178 is a hollow based bullet that, when seated in the case, allows the cartridge to fit in the gun. Upon firing the hollow
base expands, sealing the bore and stopping blow-by and leading.
Use a smaller bullet of soft alloy that makes a cartridge that fits in the chamber. With a fast smokeless powder or black powder the bullet may expand enough on firing to seal the bore.
Military and worn barrel throats present a condition where bullet diameters are needed that are not available in standard moulds. Many factory sporter rifles have such large throats. In this case there are two ways to remedy this:
Have a custom mould made or modify a current mould to fit such a throat, or
Fit the bullet as recommended and use a wad under the bullet that will seal the throat when the round is fired. Such wads are made from paper card and plastics and are cut with an arch punch. with a wad cutter using a drill press, or when a few wads are needed, cut with a cartridge case neck fitted and outside deburred to a knife edge so that cutting is consistent.
Wads can be cut by using a mallet tapped on the cartridge cutter on the wad material backed by a soft backer of wood, leather, or a soft plastic so as not to bend the wad cutter; chucking the cartridge wad cutter in a drill press is a good option.
If using the Lee Collet die to size cartridge necks for loading CB’s, the same die can be used to adjust the cartridge case to cut different diameter wads until the diameter is suitable for the load and chamber throat. Such wads must be at least the diameter of the throat or slightly larger and should fit the cartridge neck under the bullet with no airspace between the wad and bullet and the wad must be seated in the case neck in such a way it cannot fall into the powder space of the cartridge.
In no case should a loaded cartridge neck be larger than the chamber neck; the cartridge may not chamber and even if chambered, dangerous pressure could result. There should be enough clearance to allow the neck to expand on firing. Tight-chambered rifles built for and used by experienced cast bullet reloaders may have very little neck clearance. For the rest of us, the loaded cartridge neck should be a minimum of .002" smaller than the chamber. It is thought that greater neck clearance diminishes accuracy, so a maximum of .006"clearance should be the goal.
Bullets can be sized down in size/lube dies to fit the groove dimensions. Nose diameters cannot be reduced without custom dies. A rather simple die is available from Don Eagan; such dies are made to reduce nose diameters and are also made to taper the entire bullet to fit a tapered throat. Don advertises in The Fouling Shot and can make a die to suit a particular throat. These dies are used in place of the regular size/lube dies in RCBS and Lyman lube/sizers; once all the bullets are modified, the die is removed and the regular die is replaced for seating gas checks and lubing the bullets.
An aside on restricted bores.
Some revolver barrels are squashed where the barrel is screwed into the frame.
Some rifle barrels are squashed where a sight base or sling swivel base is swaged onto the barrel. It has been reported that some Ruger barrels with swaged-on sling swivel bases are squashed.
When the barrel is squashed the bore and groove are squozen smaller, as much as .004"-'005" has been reported. This constriction in the barrel of rifle or revolver may/will substantially reduce accuracy, may be found and measured by slugging the barrel, and may be removed by lapping or fire-lapping the barrel.