Found an awesome load development technique

[skidderman]

There is an old gunsmith on youtube I believe called The Old Gunsmith. He says he has built several custom rifles over the years. What he looks for is the lowest sd possible. Once he finds that he then plays a bit to fine tune. His premise is that low sd means consistency. To me the guy makes sense. I have not tried this or the ladder tests but I do find these ideas intriguing.

[covey ridge]

Originally Posted by skidderman

There is an old gunsmith on youtube I believe called The Old Gunsmith. He says he has built several custom rifles over the years. What he looks for is the lowest sd possible. Once he finds that he then plays a bit to fine tune. His premise is that low sd means consistency. To me the guy makes sense. I have not tried this or the ladder tests but I do find these ideas intriguing.

Would you please explain how he and you came to that conclusion?

[skidderman]

Originally Posted by covey ridge

Would you please explain how he and you came to that conclusion?

His thought process is pretty simple. If the average difference in velocity is low, say 8fps or so then the premiss is that you have made ammunition that does not vary from one round to the next. If your difference in speed is say 125 fps then something is not consistent. Without consistency it would be harder to have tight groups. Like I said I for one have not gone this far. I am a hunter, not a target shooter so I go for the best group at 100 yards & I call it a day. However if I went for consistency or low SD I might find that getting that one nice load that works really well gives me the confidence on making that one difficult shot. To me shooting is about confidence in what you & your rifle can do time after time. If I have no confidence then my chances of blowing that one shot of a lifetime might be lost. Learning about this stuff to me is like candy. It makes me want to get out & shoot & experiment more. That makes it fun, the way it should be!!!!!

[covey ridge]

Originally Posted by skidderman

His thought process is pretty simple. If the average difference in velocity is low, say 8fps or so then the premiss is that you have made ammunition that does not vary from one round to the next. If your difference in speed is say 125 fps then something is not consistent. Without consistency it would be harder to have tight groups. Like I said I for one have not gone this far. I am a hunter, not a target shooter so I go for the best group at 100 yards & I call it a day. However if I went for consistency or low SD I might find that getting that one nice load that works really well gives me the confidence on making that one difficult shot. To me shooting is about confidence in what you & your rifle can do time after time. If I have no confidence then my chances of blowing that one shot of a lifetime might be lost. Learning about this stuff to me is like candy. It makes me want to get out & shoot & experiment more. That makes it fun, the way it should be!!!!!

Thank you for that explanation. I now see where your are coming from. I may be wrong but being a hunter I sort of think that higher sectional density may be better for terminal performance even though it may not wring out the best consistency.

What gives me confidence is the ability to hit the kill zone every single time and the confidence of knowing the bullet will do its job when it gets there.

Before the development of some really good hunting bullets I nearly always chose Nosler partitions that really did not have a reputation as being tack drivers. The Nosler partitions never disappointed me.

[Soulcousin]

Originally Posted by covey ridge

Thank you for that explanation. I now see where your are coming from. I may be wrong but being a hunter I sort of think that higher sectional density may be better for terminal performance even though it may not wring out the best consistency.

What gives me confidence is the ability to hit the kill zone every single time and the confidence of knowing the bullet will do its job when it gets there.

Before the development of some really good hunting bullets I nearly always chose Nosler partitions that really did not have a reputation as being tack drivers. The Nosler partitions never disappointed me.

Gotta step in here....there are two different 'sd' terms being discussed. The sd being referred to by skidder is standard deviation, or the average difference in velocities shot to shot. Sectional density is a comparison of the weight of the bullet to the calibre (can't remember but one of those values might be squared). So for reloading a hunting round I'd strive for the highest sectional density bullet coupled with the lowest standard deviation load achieved by varying charge weight, seating depth, etc.

[covey ridge]

Originally Posted by Soulcousin

Gotta step in here....there are two different 'sd' terms being discussed. The sd being referred to by skidder is standard deviation, or the average difference in velocities shot to shot. Sectional density is a comparison of the weight of the bullet to the calibre (can't remember but one of those values might be squared). So for reloading a hunting round I'd strive for the highest sectional density bullet coupled with the lowest standard deviation load achieved by varying charge weight, seating depth, etc.

Thanks for that clarification. sd for me has always meant sectional density. I goofed up and thought skidderman and the old smith were onto using projectiles with the least bearing surface.

It does make sense that the least deviation of velocities would or should translate into the best potential for accuracy.
Thanks

[Salavee]

Originally Posted by covey ridge

Thanks for that clarification. sd for me has always meant sectional density. I goofed up and thought skidderman and the old smith were onto using projectiles with the least bearing surface.

It does make sense that the least deviation of velocities would or should translate into the best potential for accuracy.
Thanks

Lots of confusion between SD and Std Dev or StD (Standard Deviation) It's all in the way we write them.