Longshot338
CGN Regular
- Location
- Southern Ontario
Something I have noticed in my reloading activities thus far are some discrepancies between load data. One manufacturer's maximum recommended load data may differ from another. In some extreme cases, I have even noted 1 manual citing a starting charge that exceeded the maximum recommended charge of another manual.
The first question that springs to my mind is "Why do these differences exist, and why can they be so drastic?
First off, every company is using different testing equipment. I am not familiar at all with any of them, but it stands to reason that different test environments and equipment will lead to some differences in results.
Secondly, most manuals are put out by companies that manufacture projectiles. Hornaday isn't testing Speer bullets, and Barnes isn't loading Nosler projectiles for their data results. Differences in jacketing material, BC, design, crimp/cannelures, etc... exist between similar bullets. Not all bullets of the same diameter and weight perform the same.
Thirdly, (and this goes back to my first point), different rifles and test barrels are used. If one were to run the same load through a 1/12" rifled barrel and a 1/7" rifled barrel, the same velocities and pressures would not result. Likewise, a tight new bore won't produce the same results as an oversized bore (a common discrepancy in rifles like the Enfield where bores range from .310" to .324" for the same cartridge).
Finally, components may differ to a small degree. Different neck tension from different brass, crimp vs. no crimp, different primers etc... all play a role in a loads performance, and not all manufacturers use the same.
This begs the question; "where do I start and which do I trust?".
First of all, try to get data for the exact bullet you are using. If you are using a 50gr. V-Max, grab the Hornaday manual. If you are using a 180gr. Match King, try to find Sierra's data.
Secondly, take note of the test rifle/barrel being used. See how similar or different it is from the rifle you are loading for.
Thirdly, there can sometimes be found data for very specific rifles. This is one reason that I am partial to Hornaday's manual. I own an M14/M1A. Hornaday has a chapter separate from their regular 308Win data designed for the M1A service rifle. Other chapters include 30/06 data for the M1 Garand, and 5.56x45 data for the AR Service rifles. If you own specialized rifles such as these, this type of data may be of particular use to you.
Finally, try to find information from a wide variety of sources. This will give you the best indication of safety and performance overall.
I have 7 sources for data. Hornaday, Speer, Lyman, Lee, Barnes, Nosler, and Hodgdon's Data site (basically the Lee data from what I can see. I take data from every manual for each powder if I have it. I take all the starting loads for a given powder, add the grain values, and divide by the # of entries to get an average. I do the same for each manual's maximum recommended loads. I then choose a grain weight exactly halfway in between the minimum and maximum average numbers. I check to make sure it does not exceed any manual's maximum, and if it doesn't, that is the load I use.
We can capitalize on our efforts even further. This process is a very thorough method that puts all results on the same page as it were. Consider this; if you are trying to determine the powder your rifle likes the best, you will load a sample of each. Say you have 2 powders. You don't have a manual with data for both, but you have 2 manuals that covers 1 of each of your given powders in each of them. Suppose you start with each manual's starting load data. But; if 1 suggests a higher pressure/velocity load, while the other is more conservative, you get false results. The hotter of the 2 loads may give you a more consistent burn and tighter groups; leading you to believe that it is the one your rifle likes better. However, if you bring the other load up to the same pressure, you may find that it actually is the preferred powder to use in your rifle.
The procedure I have outlined gives you a very good basis to judge between powders. It puts them all on the same grounds for testing. Use it to determine the load for each different powder, and use the same primers, brass, COL, etc... Load up 10 of each, and shoot 2 5-shot groups at a range you are comfortable with.
Once I find the powder my rifle likes, I immediately start playing with the COL. I'll seat the bullets till they touch the rifling, and work back from there in 0.005" increments. Most of the time, the rifles I own like it seated right to the rifling, but I do have an Enfield No.4 Mk.I that definitely prefers that the bullet be 0.010" back.
After I have the optimum COL determined, I will go back to the powder charge, and begin upping it in reasonable increments. For smaller capacity cases like my .223 Rem, I will up it by .2gr at a time. For my Enfields and my M1A/M14, I will try .5gr. increments. Again; load 10 of each, and shoot 2 5-shot groups. This puts my mind at ease that I am not basing data on flukes...
This isn't for everyone; nor do I presume it to be the best method for developing a load. However, it has worked with great success for me. I recently perfected my load for my .223. It shot several 1/2" or less groups at 100m which I never expected any rifle in my hands to do. It went from 1.5" groups with premium factory ammo to an absolute tackdriver I never believed it was capable of.
I Hope this helps somebody. I've burned a lot more bullets and powder than were necessary before my load development techniques were refined.
The first question that springs to my mind is "Why do these differences exist, and why can they be so drastic?
First off, every company is using different testing equipment. I am not familiar at all with any of them, but it stands to reason that different test environments and equipment will lead to some differences in results.
Secondly, most manuals are put out by companies that manufacture projectiles. Hornaday isn't testing Speer bullets, and Barnes isn't loading Nosler projectiles for their data results. Differences in jacketing material, BC, design, crimp/cannelures, etc... exist between similar bullets. Not all bullets of the same diameter and weight perform the same.
Thirdly, (and this goes back to my first point), different rifles and test barrels are used. If one were to run the same load through a 1/12" rifled barrel and a 1/7" rifled barrel, the same velocities and pressures would not result. Likewise, a tight new bore won't produce the same results as an oversized bore (a common discrepancy in rifles like the Enfield where bores range from .310" to .324" for the same cartridge).
Finally, components may differ to a small degree. Different neck tension from different brass, crimp vs. no crimp, different primers etc... all play a role in a loads performance, and not all manufacturers use the same.
This begs the question; "where do I start and which do I trust?".
First of all, try to get data for the exact bullet you are using. If you are using a 50gr. V-Max, grab the Hornaday manual. If you are using a 180gr. Match King, try to find Sierra's data.
Secondly, take note of the test rifle/barrel being used. See how similar or different it is from the rifle you are loading for.
Thirdly, there can sometimes be found data for very specific rifles. This is one reason that I am partial to Hornaday's manual. I own an M14/M1A. Hornaday has a chapter separate from their regular 308Win data designed for the M1A service rifle. Other chapters include 30/06 data for the M1 Garand, and 5.56x45 data for the AR Service rifles. If you own specialized rifles such as these, this type of data may be of particular use to you.
Finally, try to find information from a wide variety of sources. This will give you the best indication of safety and performance overall.
I have 7 sources for data. Hornaday, Speer, Lyman, Lee, Barnes, Nosler, and Hodgdon's Data site (basically the Lee data from what I can see. I take data from every manual for each powder if I have it. I take all the starting loads for a given powder, add the grain values, and divide by the # of entries to get an average. I do the same for each manual's maximum recommended loads. I then choose a grain weight exactly halfway in between the minimum and maximum average numbers. I check to make sure it does not exceed any manual's maximum, and if it doesn't, that is the load I use.
We can capitalize on our efforts even further. This process is a very thorough method that puts all results on the same page as it were. Consider this; if you are trying to determine the powder your rifle likes the best, you will load a sample of each. Say you have 2 powders. You don't have a manual with data for both, but you have 2 manuals that covers 1 of each of your given powders in each of them. Suppose you start with each manual's starting load data. But; if 1 suggests a higher pressure/velocity load, while the other is more conservative, you get false results. The hotter of the 2 loads may give you a more consistent burn and tighter groups; leading you to believe that it is the one your rifle likes better. However, if you bring the other load up to the same pressure, you may find that it actually is the preferred powder to use in your rifle.
The procedure I have outlined gives you a very good basis to judge between powders. It puts them all on the same grounds for testing. Use it to determine the load for each different powder, and use the same primers, brass, COL, etc... Load up 10 of each, and shoot 2 5-shot groups at a range you are comfortable with.
Once I find the powder my rifle likes, I immediately start playing with the COL. I'll seat the bullets till they touch the rifling, and work back from there in 0.005" increments. Most of the time, the rifles I own like it seated right to the rifling, but I do have an Enfield No.4 Mk.I that definitely prefers that the bullet be 0.010" back.
After I have the optimum COL determined, I will go back to the powder charge, and begin upping it in reasonable increments. For smaller capacity cases like my .223 Rem, I will up it by .2gr at a time. For my Enfields and my M1A/M14, I will try .5gr. increments. Again; load 10 of each, and shoot 2 5-shot groups. This puts my mind at ease that I am not basing data on flukes...
This isn't for everyone; nor do I presume it to be the best method for developing a load. However, it has worked with great success for me. I recently perfected my load for my .223. It shot several 1/2" or less groups at 100m which I never expected any rifle in my hands to do. It went from 1.5" groups with premium factory ammo to an absolute tackdriver I never believed it was capable of.
I Hope this helps somebody. I've burned a lot more bullets and powder than were necessary before my load development techniques were refined.
