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**44 AMP** · January 16, 2010, 02:20 PM

And finding out that the published velocity figures are at best, only a guideline.

Guns with longer or shorter barreals will give you a different number. Shoot at 0 degrees temp and get a different number than the same gun and ammo at 70 degrees. Shoot a gun with the same barrel length as the test gun, and still get a different number, due to variations in the interaction between all components. Usually less than 100fps, but greater differences are by no means uncommon.

Each powder/bullet/case/primer combination will deliver a certain speed, in your gun. It can be a different speed in my gun, even if my gun appears identical to yours. This is a simple, but not well known fact of life. Before personal chronographs became common (affordable), few people recognised this. Today, more are learning.

What is in the loading data, or on the ammo boxes or in the catalogues is what they got with their ammo, in their test gun. What velocity you get, and whaty is a safe maximum working pressure, in your gun, can only be determined by firing and testing in your gun!

I have seen guns that safely handle loads well above the maximums listed in the manuals. I have also seen guns that gave signs of dangerous pressures from the recommended "starting loads". Every gun is an individual in that regard. While most fall into the same general groups, there are exceptions, and the exceptions can be drastically different than the general group performance. There is no way to tell from a visual inspection. Only shooting, and careful tracking of all the performance indicators will show what, and how much is different from the "average".

I would expect a rifle with a 30 inch barrel to chronograph higher velocities that "standard" piblished data, as most of that is taken using a 22" or 24" inch barrel (in suitable calibers).

Yes, Federal 210M are magnum primers, intended to reliably ignite large volumes of slow burning powders. Their performance with faster burning powders may not be what you expect. Sometimes magnum primers deliver a significant velocity increase with medium burning rate powders (along with an increase in pressure). Sometimes they do not, and only increase the pressures, especially in smaller than magnum size cases.

This belongs in the handloading forum, I think.

January 16, 2010, 02:20 PM	#2
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 30,460	Welcome to the wonderful world of having your own chrony! And finding out that the published velocity figures are at best, only a guideline. Guns with longer or shorter barreals will give you a different number. Shoot at 0 degrees temp and get a different number than the same gun and ammo at 70 degrees. Shoot a gun with the same barrel length as the test gun, and still get a different number, due to variations in the interaction between all components. Usually less than 100fps, but greater differences are by no means uncommon. Each powder/bullet/case/primer combination will deliver a certain speed, in your gun. It can be a different speed in my gun, even if my gun appears identical to yours. This is a simple, but not well known fact of life. Before personal chronographs became common (affordable), few people recognised this. Today, more are learning. What is in the loading data, or on the ammo boxes or in the catalogues is what they got with their ammo, in their test gun. What velocity you get, and whaty is a safe maximum working pressure, in your gun, can only be determined by firing and testing in your gun! I have seen guns that safely handle loads well above the maximums listed in the manuals. I have also seen guns that gave signs of dangerous pressures from the recommended "starting loads". Every gun is an individual in that regard. While most fall into the same general groups, there are exceptions, and the exceptions can be drastically different than the general group performance. There is no way to tell from a visual inspection. Only shooting, and careful tracking of all the performance indicators will show what, and how much is different from the "average". I would expect a rifle with a 30 inch barrel to chronograph higher velocities that "standard" piblished data, as most of that is taken using a 22" or 24" inch barrel (in suitable calibers). Yes, Federal 210M are magnum primers, intended to reliably ignite large volumes of slow burning powders. Their performance with faster burning powders may not be what you expect. Sometimes magnum primers deliver a significant velocity increase with medium burning rate powders (along with an increase in pressure). Sometimes they do not, and only increase the pressures, especially in smaller than magnum size cases. This belongs in the handloading forum, I think. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.