4007SSC....Questions and Discussion

[ChrisA]

Is it possible the chrony is reading low? Probably not if you tested your Father's load and it seemed ok. Just a thought.

Chris

[xswanted]

Originally Posted by ChrisA

Is it possible the chrony is reading low? Probably not if you tested your Father's load and it seemed ok. Just a thought.

Chris

That was my first assumption but the old man's 22-6 went across it only 50fps slower than 40 degrees. So its right in the wheel house on that one.

[MIBULLETS]

Supposedly even temp insensative powders can be sensative in the right senario. I think I read that somewhere. In the article they said that each powder was basically tuned for specific use cases or case volumes. Once you are outside of that volume you should expect to see some velocity variation with temperature swings. Only what I've read, no data from personal testing but thought I would throw it up here to see if it stimulates any discussion or if anyone else heard something similar....

[xswanted]

Originally Posted by MIBULLETS

Supposedly even temp insensative powders can be sensative in the right senario. I think I read that somewhere. In the article they said that each powder was basically tuned for specific use cases or case volumes. Once you are outside of that volume you should expect to see some velocity variation with temperature swings. Only what I've read, no data from personal testing but thought I would throw it up here to see if it stimulates any discussion or if anyone else heard something similar....

I think this is the answer here. It sounds like 4007 was designed more for a larger volume case. The 22-6 of my dads is running way more powder than my 250. I'm thinking the cold actually did cause the velocity change. Last winter it could have been that my ammo wasn't cold like it was the other day.

[MIBULLETS]

Like I said, I don't know that for sure, but I also see this on the Accurate Powders website in their FAQ...

Most of our powders are not insensitive, and will show some effect at hot and cold temperatures.

However, we test at -40F and +125F and the deviation in most cases are ca 3% to 5% at these extreme levels. Therefore most shooters do not notice much difference under normal practical hunting conditions.

More elaboration on the subject:

Complete temperature stability can only be achieved with tubular extruded powders designs, either with double base (NG) and/or with other coating technologies.

Because the ballistic performance at extreme temperature is completely dependant on the specific combination, it is very difficult to quantify and qualify.

Our standard powders perform very well at extreme temperatures, and usually pass the strict military requirements by a large margin.

This is a subject that often fraught with misconceptions and inaccuracies.

The term is used loosely by manufacturers without qualifying the subject, and is obviously exploited for marketing purposes and perceptions.

The facts are:
•Although powders can be improved, it’s really only possible with advanced coating procedures and additives which increase the cost.
•A particular powder can be improved re temperature stability for certain combinations, within a certain envelope which is specific to the following three main parameters/aspects ◦The caliber.
◦The weight of the projectile/bullet.
◦The performance level.


If any of these parameters/aspects go beyond or outside the intended ratio/s, the results will change and the performance will sometimes be different.

It is also very important that when a comparison is made, that all conditions re weapon i.e. components primer, case, bullet and the velocity are equal, and preferably done at the same time on the same day.

[xswanted]

Originally Posted by MIBULLETS

Like I said, I don't know that for sure, but I also see this on the Accurate Powders website in their FAQ...

Most of our powders are not insensitive, and will show some effect at hot and cold temperatures.

However, we test at -40F and +125F and the deviation in most cases are ca 3% to 5% at these extreme levels. Therefore most shooters do not notice much difference under normal practical hunting conditions.

More elaboration on the subject:

Complete temperature stability can only be achieved with tubular extruded powders designs, either with double base (NG) and/or with other coating technologies.

Because the ballistic performance at extreme temperature is completely dependant on the specific combination, it is very difficult to quantify and qualify.

Our standard powders perform very well at extreme temperatures, and usually pass the strict military requirements by a large margin.

This is a subject that often fraught with misconceptions and inaccuracies.

The term is used loosely by manufacturers without qualifying the subject, and is obviously exploited for marketing purposes and perceptions.

The facts are:
•Although powders can be improved, it’s really only possible with advanced coating procedures and additives which increase the cost.
•A particular powder can be improved re temperature stability for certain combinations, within a certain envelope which is specific to the following three main parameters/aspects ◦The caliber.
◦The weight of the projectile/bullet.
◦The performance level.


If any of these parameters/aspects go beyond or outside the intended ratio/s, the results will change and the performance will sometimes be different.

It is also very important that when a comparison is made, that all conditions re weapon i.e. components primer, case, bullet and the velocity are equal, and preferably done at the same time on the same day.

Very good read there. Thats probably the most logical piece on powder temp I've read.

Thanks!

[SShooterZ]

I've been testing 4007SSC in my .243 and 6MM. I want to try it in my .22-250 too. I too heard that it was going discontinued but I have about 12 lbs of it so I'm not too worried.

Results have been promising for me. Accuracy has been good, but haven't chronoed yet.