Bonz
01-25-2015, 10:02 AM
Proper reloading practices
Beyond the basic's, Reloading for accuracy.
With the recent influx of new shooters, as well as veteran shooters, new to the world of custom rifles, we have seen a lot of confusion on match prepping ammo for such firearms. Please understand, prepping ammo for a match or minimum SAAMI chamber can be very different than prepping ammo for a NATO chamber or a loose chamber on a factory rifle. Please feel free to critique and correct as you see fit with your own personal experiences. We are typing this as veterans of competitive shooting (including but not limited to: High Power/Service Rifle, Bench Rest, Silhouette as well as Bullseye Pistol) as well as reloading for the same, but we are humble enough to admit that we do not know everything there is to know about shooting and reloading. We have made our own mistakes in the past, and have learned from them. We hope to pass some lessons learned on to reloaders/shooters that are struggling with similar issues but aren’t sure what or who to ask. Most of the returns that we see for function and even accuracy issues are traced back to improperly reloaded ammunition, or even poor or damaged factory ammunition, and can be solved by simply following these steps.
Properly sizing brass.
Get a case gauge for the cartridge you are reloading for, this is an invaluable tool when it comes to sizing brass. A case gauge is essentially a ‘chamber’ in a piece of steel with a hi/low limit step at the base to check headspace of your brass (checking from a datum point on the shoulder to the base of the case head), as well as a hi/low limit step at the case mouth to determine proper trim length. If one is not available for the cartridge you are loading for, have one made by a custom gunsmith. Do not believe that screwing your sizing die down to the shell holder will properly size it. We have had two personal incidents where doing this (following the die manufacturers instructions) has pushed the shoulder back .050” too far on a set of .308 dies, and also did not size the shoulder back far enough (by .005”) on a set of .223 dies. In both cases, the case gauge showed this on the first piece of brass sized! The .308 was an easy fix, just unscrew the die in the press by the .050” that it was short. The .223 needed .005” removed from the top of the shell holder on a precision grinder to correct the problem. Now that shell holder is ‘married’ to that sizing die for life. Some benchrest shooters and other advanced reloaders / long range shooters will even have custom dies made to re-size brass and seat bullets to there specific chamber, also using special "arbor press" type reloading presses for these operations.
If the shoulder on your brass is pushed back too far, at ‘best’ you will have accuracy issues, at ‘worst’ you can have a failure to extract or failure to fire because the cartridge is pushed too far into the chamber. Or, it could fire, stretching the brass too far, too fast, and you could split or separate a case. If it is not sized back far enough for the chamber in your rifle, you can have a failure to feed or completely close the bolt. Depending on the length and the rifle type, this could result in firing out of battery and can be extremely dangerous!
Properly sizing brass is even MORE important if you are firing brass in a loose chamber, then sizing it for a match or minimum tolerance chamber. Brass springs back a bit after sizing and it is common for .223 Rem ammo fired in a NATO chamber to not size properly, even with a full length die, to fit into a minimum SAAMI .223 Remington chamber. In these cases a “Small Base” sizing die may need to be used, but still does not guarantee it will fully re-size brass fired in a loose chamber to the point that it will work in your minnimum SAAMI chamber. WHENEVER POSSIBLE a rilfe barrel with a new match chamber should only be fired with new unfired brass for the first time, then that brass re-sized and used in that rifle/chamber only. Even rifles chambered with the same reamer can vary enough that brass sizing can be an issue. Please keep this in mind when you have an "It works in rifle "A" but not rifle "B" " issue with your ammo.
5.56 NATO is NOT .223 Remington. Although nearly identical in outside dimensions they should be treated as different cartridges. You can shoot .223 Rem in a NATO chamber, but it will expand to fit the looser chamber, and will not give premium accuracy. Unfired 5.56 NATO brass will “fit” into a .223 Rem chamber, but NATO ammo is loaded to higher pressures, making it unsafe, or at the least, uncertain in it’s pressures, to properly operate in a tight SAAMI .223 Remington chamber. 5.56 NATO ammo in a .223 Rem SAAMI chamber will almost always cause some sort of pressure and/or function issue and it should not be used. There is a long running debate over this issue, and we do not wish to argue it. These are the findings that our experience has shown, and it is our company’s stand on it. Please don’t call to discuss that “It has worked for you in the past.” If it has, you have been lucky, it will eventually not work, most likely when you start to attempt it in a minimum SAAMI spec chamber such as we provide. The solution to shooting both 5.56 NATO and .223 Rem through the same rifle with a moderate amount of accuracy is to use the .223 Wylde chamber. This chamber is looser than a minimum SAAMI chamber, but tighter than a NATO chamber. There is the issue of the ammunition still being within a dimensional specification to work, even in the Wylde chamber. We have seen some examples of M193 ammo with bullet diameters over .224". This condition will cause feeding, function, and pressure issues in any properly sized barrel/chamber combination.
Properly sizing brass also includes trimming the cases to the proper length for your chamber, and properly deburring/chamfering cases. If the case is longer than the maximum case length listed in your reloading manual, the neck of the case will actually flow into the throat portion of the chamber, “pinching” the bullet or severely increasing neck tension, resulting in high, or even dangerous pressures. This can/will also impede function and accuracy.
Neck diameter or clearance between the case and the chamber is important as well. Common match rifle practice is to have about .002” to .003” clearance between the neck diameter of a loaded cartridge and the diameter of the neck of the chamber. This allows for the case to expand a minimal amount (extending brass life) while also allowing for dimensional changes in the steel as it heats up. Any tighter than this and you can have pressure/function problems, any looser than this and you cannot expect the best accuracy out of your barrel. Neck turning/reaming brass is a great way to uniform brass thickness to give consistent neck tension on the bullet, but keep in mind, for every .001” you turn off the diameter of the neck, you increase the clearance in the chamber by .001”. So although you may be uniforming the neck thickness of the brass, you are making the neck clearance larger. The only solution to this is to use a “tight neck” chambering reamer when your barrel is fitted to your action. Then turn your necks for proper clearance in the chamber you have.
Other items to consider when prepping brass is cleaning primer pockets on fired brass, de-burr primer flash holes (inside), weighing cases and segregating them into groups, etc. The better quality brass you start out with, the better your results will be. We are not going to recommend particular brands of brass, bullets, primers, powder, etc. Nor will we give ANY load data for liability reasons. Every rifle will like something different as far as powder charges, type of powder, bullet seating depth, etc. This will have to be determined with your load development for each particular rifle.
Weighing components.
A very important part of reloading for accuracy is weighing components. For maximum accuracy Brass & Bullets should be within about .2 (two tenths of a grain), and powder charges should be within .1 (one tenth of a grain). Brass can also be sorted by ‘water capacity’ in cc’s to segregate brass by volume or inside area capacity.
Some long range shooters, want powder charges closer than that. There are electronic scales on the market that will measure to .01 grains, but care must be used with these as they are extremely sensitive to vibration, noise, and even fluorescent lights! For reference, one kernel of Varget powder weighs about .03 grains, so unless you are using ball or flake powder, you can’t get to within .01 grains, but the ability to measure that small is helpful when trying to create the most accurate ammo you can. Benchrest shooters are known to simply go by case volume and pay little attention to the actual weight of the charge. In theory, weight and volume would go together, but the ‘looser’ the powder is packed the more volume it will consume while still having the same weight on a scale. They will use some extremely accurate powder measurers with drop tubes to give a very uniform volume of powder for each ‘throw’. A case that holds 90 grains of powder is going to be less affected by a variance of .1 grains than a case that holds 45 grains of powder. Keep this in mind when sweating over a variance in powder charges.
Bullet Ogive’s and Cartridge overall length.
Bullets of similar weights but from different manufacturers will have varying lengths and ogive shape. The ogive is the tapered part of the bullet between the tip and the bearing surface. This is the part of the bullet that first contacts the throat and will determine cartridge overall length when touching the lands. Not only will bullets from different manufacturers produce a different OAL when touching the lands, but bullets from one manufacturer, and from different lot’s can do the same. When setting OAL for ammunition that you are loading, always use a bullet from that particular box to set this length. If you are tracking throat erosion over the life of the barrel, use ONE bullet that you keep with your Stoney Point/Hornady OAL gauge. This way you are measuring the throat with the exact same ogive dimensions every time you check throat wear.
What we have found in most cases, the best accuracy is achieved when the bullet has about .010” to .015” jump to the lands. Some rifles need more jump, some need less. Some rifles give their best accuracy with the bullet “jammed” in the lands, meaning you set your ammunition LONGER than your OAL gauge shows as touching the lands. Caution should be used with this technique though as jamming a bullet in the lands, then trying to open the bolt on a loaded round can result in the bullet sticking in the throat, and you ejecting a case full of powder all over the inside of your action and trigger! Also, this method should NEVER be used with a semi auto, especially with a floating firing pin. The bullet hitting the lands can slow the bolts forward motion, causing the inertia of the firing pin to strike the primer with the cartridge out of battery. This can be extremely dangerous!
We hope this helps you get started. There are many books and publications on the market that cover these subjects in great detail and should be referred to. The information given here is to simply get you started down the road to properly create accurate ammunition for your competition or high end sporting rifle, and make you aware of the steps you need to take to produce the most accurate rifle with the best ammunition possible. This by no means is intended to give the highest level of reloading information. It is simply the next step up from basic reloading practices to help identify some of the additional steps "Beyond the basic's" that you need to know when reloading for accuracy.
Please check out Sinclair International (http://www.sinclairintl.com/) for a complete catalog containing a great selection of basic and advanced reloading equipment for the novice through experienced shooter/reloader.
Thank you,
Krieger Barrels
Beyond the basic's, Reloading for accuracy.
With the recent influx of new shooters, as well as veteran shooters, new to the world of custom rifles, we have seen a lot of confusion on match prepping ammo for such firearms. Please understand, prepping ammo for a match or minimum SAAMI chamber can be very different than prepping ammo for a NATO chamber or a loose chamber on a factory rifle. Please feel free to critique and correct as you see fit with your own personal experiences. We are typing this as veterans of competitive shooting (including but not limited to: High Power/Service Rifle, Bench Rest, Silhouette as well as Bullseye Pistol) as well as reloading for the same, but we are humble enough to admit that we do not know everything there is to know about shooting and reloading. We have made our own mistakes in the past, and have learned from them. We hope to pass some lessons learned on to reloaders/shooters that are struggling with similar issues but aren’t sure what or who to ask. Most of the returns that we see for function and even accuracy issues are traced back to improperly reloaded ammunition, or even poor or damaged factory ammunition, and can be solved by simply following these steps.
Properly sizing brass.
Get a case gauge for the cartridge you are reloading for, this is an invaluable tool when it comes to sizing brass. A case gauge is essentially a ‘chamber’ in a piece of steel with a hi/low limit step at the base to check headspace of your brass (checking from a datum point on the shoulder to the base of the case head), as well as a hi/low limit step at the case mouth to determine proper trim length. If one is not available for the cartridge you are loading for, have one made by a custom gunsmith. Do not believe that screwing your sizing die down to the shell holder will properly size it. We have had two personal incidents where doing this (following the die manufacturers instructions) has pushed the shoulder back .050” too far on a set of .308 dies, and also did not size the shoulder back far enough (by .005”) on a set of .223 dies. In both cases, the case gauge showed this on the first piece of brass sized! The .308 was an easy fix, just unscrew the die in the press by the .050” that it was short. The .223 needed .005” removed from the top of the shell holder on a precision grinder to correct the problem. Now that shell holder is ‘married’ to that sizing die for life. Some benchrest shooters and other advanced reloaders / long range shooters will even have custom dies made to re-size brass and seat bullets to there specific chamber, also using special "arbor press" type reloading presses for these operations.
If the shoulder on your brass is pushed back too far, at ‘best’ you will have accuracy issues, at ‘worst’ you can have a failure to extract or failure to fire because the cartridge is pushed too far into the chamber. Or, it could fire, stretching the brass too far, too fast, and you could split or separate a case. If it is not sized back far enough for the chamber in your rifle, you can have a failure to feed or completely close the bolt. Depending on the length and the rifle type, this could result in firing out of battery and can be extremely dangerous!
Properly sizing brass is even MORE important if you are firing brass in a loose chamber, then sizing it for a match or minimum tolerance chamber. Brass springs back a bit after sizing and it is common for .223 Rem ammo fired in a NATO chamber to not size properly, even with a full length die, to fit into a minimum SAAMI .223 Remington chamber. In these cases a “Small Base” sizing die may need to be used, but still does not guarantee it will fully re-size brass fired in a loose chamber to the point that it will work in your minnimum SAAMI chamber. WHENEVER POSSIBLE a rilfe barrel with a new match chamber should only be fired with new unfired brass for the first time, then that brass re-sized and used in that rifle/chamber only. Even rifles chambered with the same reamer can vary enough that brass sizing can be an issue. Please keep this in mind when you have an "It works in rifle "A" but not rifle "B" " issue with your ammo.
5.56 NATO is NOT .223 Remington. Although nearly identical in outside dimensions they should be treated as different cartridges. You can shoot .223 Rem in a NATO chamber, but it will expand to fit the looser chamber, and will not give premium accuracy. Unfired 5.56 NATO brass will “fit” into a .223 Rem chamber, but NATO ammo is loaded to higher pressures, making it unsafe, or at the least, uncertain in it’s pressures, to properly operate in a tight SAAMI .223 Remington chamber. 5.56 NATO ammo in a .223 Rem SAAMI chamber will almost always cause some sort of pressure and/or function issue and it should not be used. There is a long running debate over this issue, and we do not wish to argue it. These are the findings that our experience has shown, and it is our company’s stand on it. Please don’t call to discuss that “It has worked for you in the past.” If it has, you have been lucky, it will eventually not work, most likely when you start to attempt it in a minimum SAAMI spec chamber such as we provide. The solution to shooting both 5.56 NATO and .223 Rem through the same rifle with a moderate amount of accuracy is to use the .223 Wylde chamber. This chamber is looser than a minimum SAAMI chamber, but tighter than a NATO chamber. There is the issue of the ammunition still being within a dimensional specification to work, even in the Wylde chamber. We have seen some examples of M193 ammo with bullet diameters over .224". This condition will cause feeding, function, and pressure issues in any properly sized barrel/chamber combination.
Properly sizing brass also includes trimming the cases to the proper length for your chamber, and properly deburring/chamfering cases. If the case is longer than the maximum case length listed in your reloading manual, the neck of the case will actually flow into the throat portion of the chamber, “pinching” the bullet or severely increasing neck tension, resulting in high, or even dangerous pressures. This can/will also impede function and accuracy.
Neck diameter or clearance between the case and the chamber is important as well. Common match rifle practice is to have about .002” to .003” clearance between the neck diameter of a loaded cartridge and the diameter of the neck of the chamber. This allows for the case to expand a minimal amount (extending brass life) while also allowing for dimensional changes in the steel as it heats up. Any tighter than this and you can have pressure/function problems, any looser than this and you cannot expect the best accuracy out of your barrel. Neck turning/reaming brass is a great way to uniform brass thickness to give consistent neck tension on the bullet, but keep in mind, for every .001” you turn off the diameter of the neck, you increase the clearance in the chamber by .001”. So although you may be uniforming the neck thickness of the brass, you are making the neck clearance larger. The only solution to this is to use a “tight neck” chambering reamer when your barrel is fitted to your action. Then turn your necks for proper clearance in the chamber you have.
Other items to consider when prepping brass is cleaning primer pockets on fired brass, de-burr primer flash holes (inside), weighing cases and segregating them into groups, etc. The better quality brass you start out with, the better your results will be. We are not going to recommend particular brands of brass, bullets, primers, powder, etc. Nor will we give ANY load data for liability reasons. Every rifle will like something different as far as powder charges, type of powder, bullet seating depth, etc. This will have to be determined with your load development for each particular rifle.
Weighing components.
A very important part of reloading for accuracy is weighing components. For maximum accuracy Brass & Bullets should be within about .2 (two tenths of a grain), and powder charges should be within .1 (one tenth of a grain). Brass can also be sorted by ‘water capacity’ in cc’s to segregate brass by volume or inside area capacity.
Some long range shooters, want powder charges closer than that. There are electronic scales on the market that will measure to .01 grains, but care must be used with these as they are extremely sensitive to vibration, noise, and even fluorescent lights! For reference, one kernel of Varget powder weighs about .03 grains, so unless you are using ball or flake powder, you can’t get to within .01 grains, but the ability to measure that small is helpful when trying to create the most accurate ammo you can. Benchrest shooters are known to simply go by case volume and pay little attention to the actual weight of the charge. In theory, weight and volume would go together, but the ‘looser’ the powder is packed the more volume it will consume while still having the same weight on a scale. They will use some extremely accurate powder measurers with drop tubes to give a very uniform volume of powder for each ‘throw’. A case that holds 90 grains of powder is going to be less affected by a variance of .1 grains than a case that holds 45 grains of powder. Keep this in mind when sweating over a variance in powder charges.
Bullet Ogive’s and Cartridge overall length.
Bullets of similar weights but from different manufacturers will have varying lengths and ogive shape. The ogive is the tapered part of the bullet between the tip and the bearing surface. This is the part of the bullet that first contacts the throat and will determine cartridge overall length when touching the lands. Not only will bullets from different manufacturers produce a different OAL when touching the lands, but bullets from one manufacturer, and from different lot’s can do the same. When setting OAL for ammunition that you are loading, always use a bullet from that particular box to set this length. If you are tracking throat erosion over the life of the barrel, use ONE bullet that you keep with your Stoney Point/Hornady OAL gauge. This way you are measuring the throat with the exact same ogive dimensions every time you check throat wear.
What we have found in most cases, the best accuracy is achieved when the bullet has about .010” to .015” jump to the lands. Some rifles need more jump, some need less. Some rifles give their best accuracy with the bullet “jammed” in the lands, meaning you set your ammunition LONGER than your OAL gauge shows as touching the lands. Caution should be used with this technique though as jamming a bullet in the lands, then trying to open the bolt on a loaded round can result in the bullet sticking in the throat, and you ejecting a case full of powder all over the inside of your action and trigger! Also, this method should NEVER be used with a semi auto, especially with a floating firing pin. The bullet hitting the lands can slow the bolts forward motion, causing the inertia of the firing pin to strike the primer with the cartridge out of battery. This can be extremely dangerous!
We hope this helps you get started. There are many books and publications on the market that cover these subjects in great detail and should be referred to. The information given here is to simply get you started down the road to properly create accurate ammunition for your competition or high end sporting rifle, and make you aware of the steps you need to take to produce the most accurate rifle with the best ammunition possible. This by no means is intended to give the highest level of reloading information. It is simply the next step up from basic reloading practices to help identify some of the additional steps "Beyond the basic's" that you need to know when reloading for accuracy.
Please check out Sinclair International (http://www.sinclairintl.com/) for a complete catalog containing a great selection of basic and advanced reloading equipment for the novice through experienced shooter/reloader.
Thank you,
Krieger Barrels